Android studio 3.1.3 初始化项目 build 失败问题

本机环境：mac 10.12.6 . Android Studio 3.1.3 代理已测试可连结youtube.com  build.gradle ``` apply plugin: 'com.android.application' android { compileSdkVersion 28 defaultConfig { applicationId "com.example.hubs.ok" minSdkVersion 19 targetSdkVersion 28 versionCode 1 versionName "1.0" testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner" } buildTypes { release { minifyEnabled false proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro' } } buildToolsVersion '28.0.1' compileOptions { sourceCompatibility JavaVersion.VERSION_1_8 targetCompatibility JavaVersion.VERSION_1_8 } } dependencies { implementation fileTree(include: ['*.jar'], dir: 'libs') implementation 'com.android.support:appcompat-v7:28.0.0-alpha3' implementation 'com.android.support.constraint:constraint-layout:1.1.2' testImplementation 'junit:junit:4.12' androidTestImplementation 'com.android.support.test:runner:1.0.2' androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2' } ``` 点击编译时一直卡在Download ....  命令行里gradlew build 也一直卡在这  本地curl -i 是可以访问链接的  到底是什么原因呢...崩溃了....哪些同学遇到过这个情况？谢谢。

android studio 5.0以下编译不成功

android studio classpath 'com.android.tools.build:gradle:2.0.0' 这能编译成功5.0以上的，以下的都编译不成功 bulid。gradle： compileSdkVersion 23 buildToolsVersion "23.0.1" defaultConfig { minSdkVersion 14 targetSdkVersion 23 versionCode 1 versionName "1" } 如果将.build:gradle:2.0.0 改成1.2.3的话连5.0都编译不成功了 编译失败的原因是导包重复 Error:Execution failed for task ':app:transformClassesWithDexForDebug'. > com.android.build.api.transform.TransformException: com.android.ide.common.process.ProcessException: java.util.concurrent.ExecutionException: com.android.ide.common.process.ProcessException: org.gradle.process.internal.ExecException: Process 'command 'D:\Program Files\Java\jdk1.7\bin\java.exe'' finished with non-zero exit value 2 跪求大牛帮忙解答。。。

Android Studio2.3.3真机调试安装失败

为什么使用avd就能安装成功，真机就不能安装成功？ 提示如图 

Android Studio 升级到3.5的错误

Android Studio 弹出升级的消息框，手贱点了一下 ，然后升级到了Android Studio3.5，升级完成后打开Android Studio ，提示升级失败，查看错误为： java.lang.UnsatisfiedLinkError: org.sqlite.core.NativeDB._open_utf8([BI)V at org.sqlite.core.NativeDB._open_utf8(Native Method) at org.sqlite.core.NativeDB._open(NativeDB.java:71) at org.sqlite.core.DB.open(DB.java:174) at org.sqlite.core.CoreConnection.open(CoreConnection.java:220) at org.sqlite.core.CoreConnection.<init>(CoreConnection.java:76) at org.sqlite.jdbc3.JDBC3Connection.<init>(JDBC3Connection.java:25) at org.sqlite.jdbc4.JDBC4Connection.<init>(JDBC4Connection.java:24) at org.sqlite.SQLiteConnection.<init>(SQLiteConnection.java:45) at org.sqlite.JDBC.createConnection(JDBC.java:114) at org.sqlite.JDBC.connect(JDBC.java:88) at java.sql.DriverManager.getConnection(DriverManager.java:664) at java.sql.DriverManager.getConnection(DriverManager.java:270) at com.android.tools.deployer.SqlApkFileDatabase.<init>(SqlApkFileDatabase.java:62) at com.android.tools.deployer.SqlApkFileDatabase.<init>(SqlApkFileDatabase.java:50) at com.android.tools.idea.run.DeploymentService.<init>(DeploymentService.java:56) at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) at java.lang.reflect.Constructor.newInstance(Constructor.java:423) at org.picocontainer.defaults.InstantiatingComponentAdapter.newInstance(InstantiatingComponentAdapter.java:193) at com.intellij.util.pico.CachingConstructorInjectionComponentAdapter.doGetComponentInstance(CachingConstructorInjectionComponentAdapter.java:92) at com.intellij.util.pico.CachingConstructorInjectionComponentAdapter.instantiateGuarded(CachingConstructorInjectionComponentAdapter.java:66) at com.intellij.util.pico.CachingConstructorInjectionComponentAdapter.getComponentInstance(CachingConstructorInjectionComponentAdapter.java:48) at com.intellij.openapi.components.impl.ServiceManagerImpl$MyComponentAdapter.createAndInitialize(ServiceManagerImpl.java:222) at com.intellij.openapi.components.impl.ServiceManagerImpl$MyComponentAdapter.lambda$getComponentInstance$0(ServiceManagerImpl.java:209) at com.intellij.openapi.components.impl.ServiceManagerImpl$MyComponentAdapter.getComponentInstance(ServiceManagerImpl.java:213) at com.intellij.util.pico.DefaultPicoContainer.getLocalInstance(DefaultPicoContainer.java:246) at com.intellij.util.pico.DefaultPicoContainer.getComponentInstance(DefaultPicoContainer.java:213) at com.intellij.openapi.components.ServiceManager.doGetService(ServiceManager.java:52) at com.intellij.openapi.components.ServiceManager.getService(ServiceManager.java:30) at com.android.tools.idea.run.DeploymentService.getInstance(DeploymentService.java:48) at com.android.tools.idea.deploy.DeployActionsInitializer.updateDeployableProvider(DeployActionsInitializer.java:184) at com.android.tools.idea.deploy.DeployActionsInitializer.access$000(DeployActionsInitializer.java:56) at com.android.tools.idea.deploy.DeployActionsInitializer$1.projectOpened(DeployActionsInitializer.java:123) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) at com.intellij.util.messages.impl.MessageBusConnectionImpl.deliverMessage(MessageBusConnectionImpl.java:114) at com.intellij.util.messages.impl.MessageBusImpl.doPumpMessages(MessageBusImpl.java:393) at com.intellij.util.messages.impl.MessageBusImpl.pumpWaitingBuses(MessageBusImpl.java:354) at com.intellij.util.messages.impl.MessageBusImpl.pumpMessages(MessageBusImpl.java:343) at com.intellij.util.messages.impl.MessageBusImpl.sendMessage(MessageBusImpl.java:320) at com.intellij.util.messages.impl.MessageBusImpl.access$100(MessageBusImpl.java:29) at com.intellij.util.messages.impl.MessageBusImpl$1.invoke(MessageBusImpl.java:192) at com.sun.proxy.$Proxy17.projectOpened(Unknown Source) at com.intellij.openapi.project.impl.ProjectManagerImpl.fireProjectOpened(ProjectManagerImpl.java:780) at com.intellij.openapi.project.impl.ProjectManagerImpl.lambda$null$6(ProjectManagerImpl.java:401) at com.intellij.openapi.application.TransactionGuardImpl.lambda$submitTransactionAndWait$2(TransactionGuardImpl.java:165) at com.intellij.openapi.application.TransactionGuardImpl.runSyncTransaction(TransactionGuardImpl.java:88) at com.intellij.openapi.application.TransactionGuardImpl.lambda$submitTransaction$1(TransactionGuardImpl.java:111) at com.intellij.openapi.application.impl.LaterInvocator$FlushQueue.doRun(LaterInvocator.java:435) at com.intellij.openapi.application.impl.LaterInvocator$FlushQueue.runNextEvent(LaterInvocator.java:419) at com.intellij.openapi.application.impl.LaterInvocator$FlushQueue.run(LaterInvocator.java:403) at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:311) at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:764) at java.awt.EventQueue.access$500(EventQueue.java:98) at java.awt.EventQueue$3.run(EventQueue.java:715) at java.awt.EventQueue$3.run(EventQueue.java:709) at java.security.AccessController.doPrivileged(Native Method) at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:74) at java.awt.EventQueue.dispatchEvent(EventQueue.java:734) at com.intellij.ide.IdeEventQueue.defaultDispatchEvent(IdeEventQueue.java:757) at com.intellij.ide.IdeEventQueue._dispatchEvent(IdeEventQueue.java:706) at com.intellij.ide.IdeEventQueue.dispatchEvent(IdeEventQueue.java:375) at com.intellij.ide.IdeEventQueue.pumpEventsForHierarchy(IdeEventQueue.java:814) at com.intellij.openapi.progress.util.ProgressWindow.startBlocking(ProgressWindow.java:210) at com.intellij.openapi.progress.util.ProgressWindow.startBlocking(ProgressWindow.java:196) at com.intellij.openapi.application.impl.ApplicationImpl.runProcessWithProgressSynchronously(ApplicationImpl.java:609) at com.intellij.openapi.progress.impl.CoreProgressManager.runProcessWithProgressSynchronously(CoreProgressManager.java:454) at com.intellij.openapi.progress.impl.ProgressManagerImpl.runProcessWithProgressSynchronously(ProgressManagerImpl.java:109) at com.intellij.openapi.progress.impl.CoreProgressManager.runProcessWithProgressSynchronously(CoreProgressManager.java:251) at com.intellij.openapi.progress.impl.CoreProgressManager.runProcessWithProgressSynchronously(CoreProgressManager.java:205) at com.intellij.openapi.project.impl.ProjectManagerImpl.loadProjectUnderProgress(ProjectManagerImpl.java:450) at com.intellij.openapi.project.impl.ProjectManagerImpl.openProject(ProjectManagerImpl.java:425) at com.intellij.platform.PlatformProjectOpenProcessor.doOpenProject(PlatformProjectOpenProcessor.java:260) at com.intellij.ide.RecentProjectsManagerBase.doOpenProject(RecentProjectsManagerBase.java:512) at com.intellij.ide.RecentProjectsManagerBase.doReopenLastProject(RecentProjectsManagerBase.java:634) at com.intellij.ide.RecentProjectsManagerBase$MyAppLifecycleListener.appStarting(RecentProjectsManagerBase.java:692) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) at com.intellij.util.messages.impl.MessageBusConnectionImpl.deliverMessage(MessageBusConnectionImpl.java:114) at com.intellij.util.messages.impl.MessageBusImpl.doPumpMessages(MessageBusImpl.java:393) at com.intellij.util.messages.impl.MessageBusImpl.pumpWaitingBuses(MessageBusImpl.java:354) at com.intellij.util.messages.impl.MessageBusImpl.pumpMessages(MessageBusImpl.java:343) at com.intellij.util.messages.impl.MessageBusImpl.sendMessage(MessageBusImpl.java:320) at com.intellij.util.messages.impl.MessageBusImpl.access$100(MessageBusImpl.java:29) at com.intellij.util.messages.impl.MessageBusImpl$1.invoke(MessageBusImpl.java:192) at com.sun.proxy.$Proxy63.appStarting(Unknown Source) at com.intellij.idea.IdeaApplication$IdeStarter.lambda$main$1(IdeaApplication.java:388) at com.intellij.openapi.application.TransactionGuardImpl.runSyncTransaction(TransactionGuardImpl.java:88) at com.intellij.openapi.application.TransactionGuardImpl.lambda$submitTransaction$1(TransactionGuardImpl.java:111) at com.intellij.openapi.application.TransactionGuardImpl.submitTransaction(TransactionGuardImpl.java:120) at com.intellij.openapi.application.TransactionGuard.submitTransaction(TransactionGuard.java:121) at com.intellij.idea.IdeaApplication$IdeStarter.main(IdeaApplication.java:386) at com.intellij.idea.IdeaApplication.lambda$run$1(IdeaApplication.java:220) at com.intellij.openapi.application.TransactionGuardImpl.performUserActivity(TransactionGuardImpl.java:195) at com.intellij.idea.IdeaApplication.run(IdeaApplication.java:220) at com.intellij.idea.IdeaApplication.lambda$initApplication$0(IdeaApplication.java:77) at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:311) at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:764) at java.awt.EventQueue.access$500(EventQueue.java:98) at java.awt.EventQueue$3.run(EventQueue.java:715) at java.awt.EventQueue$3.run(EventQueue.java:709) at java.security.AccessController.doPrivileged(Native Method) at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:74) at java.awt.EventQueue.dispatchEvent(EventQueue.java:734) at com.intellij.ide.IdeEventQueue.dispatchEvent(IdeEventQueue.java:349) at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:205) at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116) at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105) at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101) at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93) at java.awt.EventDispatchThread.run(EventDispatchThread.java:82) 操作系统是Win10 专业版 64位。 以为是我的老版本导致的程序不对，然后把和Android Studio有关的文件都删了，重新安装，安装好了以后可以用了，但是关了AS，再重新打开AS，又开始报上面的错误，有没有遇到这个问题的?如何来解决这个问题？ ------------------------------------------------------------》》》》》 很白痴的问题，以及个人的习惯导致的，使用管理员权限打开就好了，AS会在AppData/Local 中创建一个临时的sqlite 数据访问的dll，不是管理员权限访问不了，就导致了这个错误。

android studio编译失败

android studio 版本从2.2更新到3.0后不论是打开之前的项目，还是新建一个项目，编译都会出现同一种错误 Error:java.util.concurrent.ExecutionException: com.android.tools.aapt2.Aapt2Exception: AAPT2 error: check logs for details 之前百度了很多，试过之后也没解决，求大神解答

Android Studio跑高德地图的demo失败

今天想试一下运行高德地图的demo，把压缩包下载好后解压，用Android Stuidio打开，一开始构建项目没有问题  但是当我点击build apks时，就出问题了 说这项工程使用的gradle版本不支持，但是我同学用就没报错，他也不知道什么情况。这个项目使用的android gradle是2.1.3版本的，gradle版本是2.14.1版本的 找了一天的bug了，有没有大佬告诉我这是哪里配置有问题吗

android APP连接mysql时，APP闪退

安卓程序连接MySQL一直不成功，本地连接可以。我是用手机调试的，点击接mysql按钮时，APP闪退。在网上找了好多方法都不行。求看看什么问题 错误日志如下： 2019-08-25 08:25:33.377 5570-5570/mark.zhang E/AndroidRuntime: FATAL EXCEPTION: main Process: mark.zhang, PID: 5570 java.lang.IllegalStateException: Could not execute method for android:onClick at android.view.View$DeclaredOnClickListener.onClick(View.java:5692) at android.view.View.performClick(View.java:6663) at android.view.View.performClickInternal(View.java:6635) at android.view.View.access$3100(View.java:794) at android.view.View$PerformClick.run(View.java:26199) at android.os.Handler.handleCallback(Handler.java:907) at android.os.Handler.dispatchMessage(Handler.java:105) at android.os.Looper.loop(Looper.java:216) at android.app.ActivityThread.main(ActivityThread.java:7625) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:524) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:987) Caused by: java.lang.reflect.InvocationTargetException at java.lang.reflect.Method.invoke(Native Method) at android.view.View$DeclaredOnClickListener.onClick(View.java:5687) at android.view.View.performClick(View.java:6663)  at android.view.View.performClickInternal(View.java:6635)  at android.view.View.access$3100(View.java:794)  at android.view.View$PerformClick.run(View.java:26199)  at android.os.Handler.handleCallback(Handler.java:907)  at android.os.Handler.dispatchMessage(Handler.java:105)  at android.os.Looper.loop(Looper.java:216)  at android.app.ActivityThread.main(ActivityThread.java:7625)  at java.lang.reflect.Method.invoke(Native Method)  at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:524)  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:987)  Caused by: java.lang.BootstrapMethodError: Exception from call site #39 bootstrap method at com.mysql.cj.jdbc.AbandonedConnectionCleanupThread.<clinit>(AbandonedConnectionCleanupThread.java:58) at java.lang.Class.classForName(Native Method) at java.lang.Class.forName(Class.java:453) at java.lang.Class.forName(Class.java:378) at com.mysql.cj.jdbc.NonRegisteringDriver.<clinit>(NonRegisteringDriver.java:99) at java.lang.Class.classForName(Native Method) at java.lang.Class.forName(Class.java:453) at java.lang.Class.forName(Class.java:378) at mark.zhang.Util.openConnection(Util.java:16) at mark.zhang.Main.onConn(Main.java:30) at java.lang.reflect.Method.invoke(Native Method)  at android.view.View$DeclaredOnClickListener.onClick(View.java:5687)  at android.view.View.performClick(View.java:6663)  at android.view.View.performClickInternal(View.java:6635)  at android.view.View.access$3100(View.java:794)  at android.view.View$PerformClick.run(View.java:26199)  at android.os.Handler.handleCallback(Handler.java:907)  at android.os.Handler.dispatchMessage(Handler.java:105)  at android.os.Looper.loop(Looper.java:216)  at android.app.ActivityThread.main(ActivityThread.java:7625)  at java.lang.reflect.Method.invoke(Native Method)  at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:524)  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:987)  Caused by: java.lang.ClassCastException: Bootstrap method returned null at com.mysql.cj.jdbc.AbandonedConnectionCleanupThread.<clinit>(AbandonedConnectionCleanupThread.java:58)  at java.lang.Class.classForName(Native Method)  at java.lang.Class.forName(Class.java:453)  at java.lang.Class.forName(Class.java:378)  at com.mysql.cj.jdbc.NonRegisteringDriver.<clinit>(NonRegisteringDriver.java:99)  at java.lang.Class.classForName(Native Method)  at java.lang.Class.forName(Class.java:453)  at java.lang.Class.forName(Class.java:378)  at mark.zhang.Util.openConnection(Util.java:16)  at mark.zhang.Main.onConn(Main.java:30)  at java.lang.reflect.Method.invoke(Native Method)  at android.view.View$DeclaredOnClickListener.onClick(View.java:5687)  at android.view.View.performClick(View.java:6663)  at android.view.View.performClickInternal(View.java:6635)  at android.view.View.access$3100(View.java:794)  at android.view.View$PerformClick.run(View.java:26199)  at android.os.Handler.handleCallback(Handler.java:907)  at android.os.Handler.dispatchMessage(Handler.java:105)  at android.os.Looper.loop(Looper.java:216)  at android.app.ActivityThread.main(ActivityThread.java:7625)  at java.lang.reflect.Method.invoke(Native Method)  at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:524)  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:987)  2019-08-25 08:25:33.398 5570-5570/mark.zhang I/Process: Sending signal. PID: 5570 SIG: 9 源码如下： 这是util.java ``` package mark.zhang; import java.sql.Connection; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; public class Util { public static Connection openConnection(String url, String user, String password) { Connection conn = null; try { final String DRIVER_NAME = "com.mysql.cj.jdbc.Driver"; Class.forName(DRIVER_NAME); conn = DriverManager.getConnection(url, user, password); } catch (ClassNotFoundException e) { conn = null; } catch (SQLException e) { conn = null; } return conn; } public static void query(Connection conn, String sql) { if (conn == null) { return; } Statement statement = null; ResultSet result = null; try { statement = conn.createStatement(); result = statement.executeQuery(sql); if (result != null && result.first()) { int idColumnIndex = result.findColumn("id"); int nameColumnIndex = result.findColumn("name"); System.out.println("id\t\t" + "name"); while (!result.isAfterLast()) { System.out.print(result.getString(idColumnIndex) + "\t\t"); System.out.println(result.getString(nameColumnIndex)); result.next(); } } } catch (SQLException e) { e.printStackTrace(); } finally { try { if (result != null) { result.close(); result = null; } if (statement != null) { statement.close(); statement = null; } } catch (SQLException sqle) { } } } public static boolean execSQL(Connection conn, String sql) { boolean execResult = false; if (conn == null) { return execResult; } Statement statement = null; try { statement = conn.createStatement(); if (statement != null) { execResult = statement.execute(sql); } } catch (SQLException e) { execResult = false; } return execResult; } } ``` 这是main.java ``` package mark.zhang; import com.mysql.cj.jdbc.AbandonedConnectionCleanupThread; import java.sql.Connection; import java.sql.SQLException; import androidx.appcompat.app.AppCompatActivity; import android.app.Activity; import android.os.Bundle; import android.view.View; import java.sql.Connection; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; public class Main extends Activity { private static final String REMOTE_IP = "223.104.64.237"; private static final String URL = "jdbc:mysql://223.104.64.237:3306/mydb?useSSL=false&serverTimezone=GMT&characterEncoding=utf-8&autoReconnect=true"; private static final String USER = "root"; private static final String PASSWORD = "123"; private Connection conn; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); } public void onConn(View view) { conn = Util.openConnection(URL, USER, PASSWORD); /* final Thread thread = new Thread(new Runnable() { @Override public void run() { // 反复尝试连接，直到连接成功后退出循环 while (!Thread.interrupted()) { try { Thread.sleep(100); // 每隔0.1秒尝试连接 } catch (InterruptedException e) { System.out.println("链接数据库"); } // 2.设置好IP/端口/数据库名/用户名/密码等必要的连接信息 String url="jdbc:mysql://223.104.64.237:3306/mydb?useSSL=false&serverTimezone=Hongkong&characterEncoding=utf-8&autoReconnect=true"; String user = "root"; String password = "123"; // 3.连接JDBC try { Class.forName("com.mysql.cj.jdbc.Driver"); Connection conn = DriverManager.getConnection(url,user,password); System.out.println("远程连接成功!"); conn.close(); return; } catch (SQLException e) { System.out.println("远程连接失败!"); } catch (ClassNotFoundException e){ } } } }); thread.start();*/ } public void onInsert(View view) { String sql = "insert into mytable values(9, 'hanmeimei')"; Util.execSQL(conn, sql); } public void onDelete(View view) { String sql = "delete from mytable where name='mark'"; Util.execSQL(conn, sql); } public void onUpdate(View view) { String sql = "update mytable set name='李磊' where name='韩美'"; Util.execSQL(conn, sql); } public void onQuery(View view) { System.out.println("All users info:"); Util.query(conn, "select * from mytable"); } @Override protected void onDestroy() { super.onDestroy(); if (conn != null) { try { conn.close(); } catch (SQLException e) { conn = null; } finally { conn = null; } } } } ```

int com_fd = newPort.openPort(uart, 0, (char) longUart);这段代码错在哪里？

package com.example.newland.serialport; import android.support.v7.app.AppCompatActivity; import android.os.Bundle; import com.newland.jni.Convert; import com.newland.jni.SerialPort;//串口类 import com.newland.jni.OnDataReceivedListener;//数据接收监听口 import android.view.View; import android.widget.CheckBox; import android.widget.CompoundButton; import android.widget.EditText; import android.widget.Spinner; import android.widget.ArrayAdapter; import android.widget.TextView; public class MainActivity extends AppCompatActivity { private String strReceiveData="";//串口接收的数据 private Spinner spBaudRate,spUart; private EditText etAck,etSend; private TextView tvUartStatus; private CheckBox chkSendHex,chkAckHex; SerialPort newPort=new SerialPort();//定义一个串口 private int[] sectCom={0,1,2,3}; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); initComponent();//初始化控件 initSpinnerBaudRate();//初始化下拉框的值 //PC机发送数据是不定时的，故采用响应模式来接收数据 newPort.setCommReceivedMode(true);//设置串口通讯为响应模式 //设置数据接收的监听器 newPort.setOnDataReceivedListener(new OnDataReceivedListener() { public void onDataReceived(String data) { handleReceivedData(data);//处理接受的数据 } }); } /**************************************** * 函数名称：initComponent * 功能描述：初始化界面 * 参数及返回值说明： * ****************************************/ private void initComponent(){ //初始化控件 tvUartStatus=(TextView)findViewById(R.id.tvUartStatus); etAck=(EditText) findViewById(R.id.etAck); etSend=(EditText)findViewById(R.id.etSend); spBaudRate=(Spinner)findViewById(R.id.spBaudRate); spUart=(Spinner)findViewById(R.id.spUart); chkSendHex=(CheckBox)findViewById(R.id.chkSendHex); chkAckHex=(CheckBox)findViewById(R.id.chkAckHex); chkSendHex.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() { public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) { String str=etSend.getText().toString(); try { if (isChecked) { etSend.setText(Convert.stringToHexString(str)); } else { etSend.setText(Convert.hexStringToString(str)); } }catch (Exception e){ } } }); //增加事件监听，实现字符串与十六进制互转 chkAckHex.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() { public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) { String str=etAck.getText().toString(); try { if (isChecked) { etAck.setText(Convert.stringToHexString(str)); } else { etAck.setText(Convert.hexStringToString(str)); } }catch (Exception e){ //TODO:handle exception } } }); } /******* * 函数名称：initSpinnerBaudRate * 功能描述：初始化波特率的值 * 参数及返回值说明：* *******/ private void initSpinnerBaudRate(){ //下拉波特率的值 String[] items={"1200","B2400","B4800","9600","19200","38400","57600","115200","230400","921600"}; //第一步：为下拉列表定义一个适配器，这里就用到里前面定义的items。 final ArrayAdapter<String>adapter=new ArrayAdapter<String>(this,android.R.layout.simple_spinner_item,items); //第二步：为适配器配置下拉列表下拉时的菜单样式。 adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item); //第三步：将适配器添加到下拉列表上 spBaudRate.setAdapter(adapter); //默认选择第6项--57600 spBaudRate.setSelection(6); //下拉串口的值 String[] uarts={"COM0","COM1","COM2","COM3"}; final ArrayAdapter<String>adapterUart=new ArrayAdapter<String>(this,android.R.layout.simple_spinner_item,uarts); adapterUart.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item); spUart.setAdapter(adapterUart); spUart.setSelection(2);//默认选择第二项--COM2 } /******* * 函数名称：myClick * 功能描述：按钮监听 * 参数及返回值说明 *******/ public void myClick(View v) { switch(v.getId()) { //打开串口 case R.id.btnOpenUart: long longUart = spUart.getSelectedItemId(); int uart = sectCom[(int) longUart]; longUart = spBaudRate.getSelectedItemId(); int com_fd = newPort.openPort(uart, 0, (char) longUart); if (com_fd > 0) { tvUartStatus.setText("打开成功！..."); } else { tvUartStatus.setText("打开失败！...");} break; //关闭串口 case R.id.btnCloseUart: newPort.closePort(); tvUartStatus.setText("已关闭！..."); break; //发送 case R.id.btnSend: String msg = etSend.getText().toString(); if (chkSendHex.isChecked()) {//以十六进制数发送 newPort.sendCommand(Convert.hexStringToCharArray(msg)); } else {//以字符串发送 newPort.sendCommand(Convert.stringToCharArray(msg)); } break; //清除按钮 case R.id.btnClear: etAck.setText(""); strReceiveData = ""; break; //退出 case R.id.btnQuit: System.exit(0); default: break; } } /************ * 函数名称：handleReceiveData * 功能描述：处理数据 * 参数说明：data，从串口中接收到的数据 ************/ protected void handleReceivedData(final String data){ runOnUiThread(new Runnable() {//通过runOnUiThread在线程中执行UI更新操作 public void run() { strReceiveData = strReceiveData + data; if (chkAckHex.isChecked()) {//十六进制显示 etAck.setText(Convert.dataToHexString(strReceiveData)); }else { etAck.setText(Convert.dataToHexString(strReceiveData));} } }); } @Override protected void onDestroy(){ super.onDestroy(); newPort.onDestroy(); } } E/JIN: WARNING:could not load libuart.so E/zygote: No implementation found for int com.newland.jni.Linuxc.openUart(int, int) (tried Java_com_newland_jni_Linuxc_openUart and Java_com_newland_jni_Linuxc_openUart__II) D/AndroidRuntime: Shutting down VM E/AndroidRuntime: FATAL EXCEPTION: main Process: com.example.newland.serialport, PID: 25212 java.lang.IllegalStateException: Could not execute method for android:onClick at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:390) at android.view.View.performClick(View.java:6256) at android.view.View$PerformClick.run(View.java:24701) at android.os.Handler.handleCallback(Handler.java:789) at android.os.Handler.dispatchMessage(Handler.java:98) at android.os.Looper.loop(Looper.java:164) at android.app.ActivityThread.main(ActivityThread.java:6541) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:240) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:767) Caused by: java.lang.reflect.InvocationTargetException at java.lang.reflect.Method.invoke(Native Method) at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:385) at android.view.View.performClick(View.java:6256)  at android.view.View$PerformClick.run(View.java:24701)  at android.os.Handler.handleCallback(Handler.java:789)  at android.os.Handler.dispatchMessage(Handler.java:98)  at android.os.Looper.loop(Looper.java:164)  at android.app.ActivityThread.main(ActivityThread.java:6541)  at java.lang.reflect.Method.invoke(Native Method)  at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:240)  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:767)  Caused by: java.lang.UnsatisfiedLinkError: No implementation found for int com.newland.jni.Linuxc.openUart(int, int) (tried Java_com_newland_jni_Linuxc_openUart and Java_com_newland_jni_Linuxc_openUart__II) at com.newland.jni.Linuxc.openUart(Native Method) at com.newland.jni.SerialPort.openPort(SerialPort.java:87) at com.example.newland.serialport.MainActivity.myClick(MainActivity.java:132) at java.lang.reflect.Method.invoke(Native Method)  at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:385)  at android.view.View.performClick(View.java:6256)  at android.view.View$PerformClick.run(View.java:24701)  at android.os.Handler.handleCallback(Handler.java:789)  at android.os.Handler.dispatchMessage(Handler.java:98)  at android.os.Looper.loop(Looper.java:164)  at android.app.ActivityThread.main(ActivityThread.java:6541)  at java.lang.reflect.Method.invoke(Native Method)  at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:240)  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:767)  Application terminated.

android studio 与后台交互问题 网络访问的问题

url返回了我需要的值 只有我在控制台点击url的时候 服务器端才会有反应 HttpResponse response = httpClient.execute(httpGet);不执行 代码如下： package com.cy.mynj.com.cy.mynj.login; import android.content.Intent; import android.os.Bundle; import android.os.Handler; import android.os.Message; import android.support.v7.app.AppCompatActivity; import android.util.Log; import android.view.View; import android.widget.Button; import android.widget.EditText; import android.widget.TextView; import android.widget.Toast; import com.cy.mynj.R; import com.cy.mynj.com.cy.mynj.activities.MainActivity; import org.apache.http.HttpEntity; import org.apache.http.HttpResponse; import org.apache.http.client.ClientProtocolException; import org.apache.http.client.HttpClient; import org.apache.http.client.methods.HttpGet; import org.apache.http.impl.client.DefaultHttpClient; import org.apache.http.util.EntityUtils; import org.json.JSONException; import org.json.JSONObject; import java.io.IOException; public class LoginActivity extends AppCompatActivity implements View.OnClickListener{ private EditText et_phone; private EditText et_password; private Button btn_login; private TextView tv_login_register; private TextView tv; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_login); initViews(); } private void initViews() { et_phone=(EditText)findViewById(R.id.et_phone); et_password=(EditText)findViewById(R.id.et_password); btn_login=(Button)findViewById(R.id.btn_login); btn_login.setOnClickListener(this); tv_login_register=(TextView)findViewById(R.id.tv_login_register); tv_login_register.setOnClickListener(this); tv=(TextView)findViewById(R.id.tv); } @Override public void onClick(View view) { String phone = et_phone.getText().toString(); String password=et_password.getText().toString(); System.out.println(phone + "," + password); System.out.println("按钮点击的线程的名字为:" + Thread.currentThread().getName()); Mythread mythread= new Mythread(phone,password); mythread.start(); } Handler handler = new Handler() { @Override public void handleMessage(Message msg) { // TODO Auto-generated method stub super.handleMessage(msg); tv.setText(Thread.currentThread().getName() + msg.obj); // 在把这个字符串变成一个JSONObejct try { JSONObject obj = new JSONObject(msg.obj.toString()); String value = obj.getString("loginstate"); System.out.println("value-->" + value); if (value.equals("success")) { Intent intent = new Intent(LoginActivity.this, MainActivity.class); startActivity(intent); } else { Toast.makeText(LoginActivity.this, "登录失败",Toast.LENGTH_SHORT ).show(); } } catch (JSONException e) { // TODO Auto-generated catch block e.printStackTrace(); } } }; private class Mythread extends Thread { private String phone; private String password; public Mythread(String phone, String password) { this.phone = phone; this.password = password; } @Override public void run () { // 在线程中请求服务器的资源 // Apache HttpClient // 1.创建HttpClient对象 HttpClient httpClient = new DefaultHttpClient(); Log.d("test", "t0"); // 2.构建请求的URL String url = "http://172.20.10.3:8080/appnews/user?phone=" + phone + "&password=" + password + "&operator=login"; // String url = "http://10.0.2.2:8080/appnews/servlet/StudentServlet"; // 3.创建HttpGet请求的对象 HttpGet httpGet = new HttpGet(url); Log.d("test4", "t4"); // 4.使用创建的httpClient执行这个httpGet请求 try { HttpResponse response = httpClient.execute(httpGet); Log.d("test3", "t3"); // 5.判断服务器端请求和应答是否成功 if (response.getStatusLine().getStatusCode() == 200) { System.out.println("请求和应答成功"); // 服务器端传输的数据的一个android封装的对象 HttpEntity entity = response.getEntity(); String msg = EntityUtils.toString(entity, "UTF-8"); System.out.println("server-->" + msg); // 在android中，子线程不能更新界面组件的值， // 因为界面组件是单线程模型，必须回到主线程更新组件的值。 // tv.setText(msg); // 构建消息对象 Message smsg = new Message(); smsg.obj = msg; handler.sendMessage(smsg); } } catch (ClientProtocolException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (IOException e) { // TODO Auto-generated catch block Log.d("test5", "t5"); e.printStackTrace(); } } } }

android studio运行报下列错误

1.貌似有问题的代码 package com.example.coolweather; import android.app.Fragment; import android.app.ProgressDialog; import android.os.Bundle; import android.support.annotation.NonNull; import android.support.annotation.Nullable; import android.util.Log; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.AdapterView; import android.widget.ArrayAdapter; import android.widget.Button; import android.widget.ListView; import android.widget.TextView; import android.widget.Toast; import com.example.coolweather.db.City; import com.example.coolweather.db.County; import com.example.coolweather.db.Province; import com.example.coolweather.util.HttpUtil; import com.example.coolweather.util.Utility; import org.litepal.crud.DataSupport; import java.io.IOException; import java.util.ArrayList; import java.util.List; import okhttp3.Call; import okhttp3.Callback; import okhttp3.Response; /** * Created by Airth on 2019/5/10. */ public class ChooseAreaFragment extends Fragment { public static final int LEVEL_PROVINCE=0; public static final int LEVEL_CITY=1; public static final int LEVEL_COUNTY=2; private ProgressDialog progressDialog; private TextView titleText; private Button backButton; private ListView listView; private ArrayAdapter<String> adapter; private List<String> dataList = new ArrayList<>(); private int currentLevel; //当前被选中的级别 private Province selectedProvince;//被选中的省份 private City selectedCity;//被选中的城市 private List<Province> provinceList;//省列表 private List<City> cityList;//市列表 private List<County> countyList ;//县列表 /*获取控件实例id*/ @Override public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) { Log.d("ChooseAreaFragment","onCreateView"); View view = inflater.inflate(R.layout.choose_area,container,false); titleText = (TextView)view.findViewById(R.id.title_text); //获取标题栏文本id backButton = (Button) view.findViewById(R.id.back_button); //获取标题栏id listView = (ListView)view.findViewById(R.id.list_view); //获取Item列表id //获取ArrayAdapter对象 adapter =new ArrayAdapter<>(getContext(), android.R.layout.simple_list_item_1, dataList); listView.setAdapter(adapter);//设置并初始化适配器 return view;//将视图返回 } /*点击事件集合*/ @Override public void onActivityCreated(@Nullable Bundle savedInstanceState) { Log.d("ChooseAreaFragment","onActivityCreated"); super.onActivityCreated(savedInstanceState); //列表任意一栏被点击，则... listView.setOnItemClickListener(new AdapterView.OnItemClickListener() { @Override public void onItemClick(AdapterView<?> parent, View view, int position, long id) { Log.d("ChooseAreaFragment","列表被点了的..."); if (currentLevel == LEVEL_PROVINCE){ //当前选中的级别为省份时 selectedProvince = provinceList.get(position); //当前点击为选中状态 queryCities();//查询市的方法 } else if (currentLevel == LEVEL_CITY){ selectedCity = cityList.get(position); queryCounties(); } } }); backButton.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { if (currentLevel == LEVEL_COUNTY){ queryCities(); } else if (currentLevel == LEVEL_CITY){ queryProvinces(); } } }); queryProvinces(); } private void queryCities() { titleText.setText(selectedProvince.getProvinceName()); //设置市的标题内容 backButton.setVisibility(View.VISIBLE); //设置返回按钮可见 //查询被选中的省份城市的市区 cityList = DataSupport.where("provinceid=?",String.valueOf(selectedProvince. getId())).find(City.class); Log.d("ChooseAreaFragment","市级"); if (cityList.size()>0){ //如果省列表不为空，则... dataList.clear(); for (City city:cityList){ //遍历每一份省的市级城市 dataList.add(city.getCityName()); //添加到数据列表中 } adapter.notifyDataSetChanged();//通知适配器数据更新了 listView.setSelection(0); currentLevel = LEVEL_CITY; } else{ int provinceCode = selectedProvince.getProvinceCode(); //获取被选取省级代码 String address = "http://guolin.tech/api/china/"+provinceCode;//获取被选取地区的网络地址 Log.d("ChooseAreaFragment","准备在网络中获取地址信息"); queryFromServer(address,"city"); // 在网络中查询 } } /*根据传入的地址和类型从服务器查询省市县数据*/ private void queryFromServer(String adress, final String type) { showProgressDialog(); // 发送一条网络请求 HttpUtil.sendOKHttpRequest(adress, new Callback() { //请求加载失败 @Override public void onFailure(Call call, IOException e) { //通过runOnUiThread方法回到主线程逻辑 getActivity().runOnUiThread(new Runnable() { @Override public void run() { closeProgressDialog(); Toast.makeText(getContext(),"加载失败",Toast.LENGTH_SHORT).show(); } }); } @Override public void onResponse(Call call, Response response) throws IOException { Log.d("ChooseAreaFragment","加载地区信息..."); String responseText = response.body().string(); boolean result = false; if ("province".equals(type)){ result = Utility.handleProvinceResponse(responseText); } else if ("city".equals(type)){ result = Utility.handleCityResponse(responseText,selectedProvince.getId()); } else if ("county".equals(type)){ result = Utility.handleCountyResponse(responseText, selectedCity.getId()); } if (result) { getActivity().runOnUiThread(new Runnable() { @Override public void run() { Log.d("ChooseAreaFragment","开启线程更新UI"); closeProgressDialog(); if ("province".equals(type)){ queryProvinces(); } else if ("city".equals(type)){ queryCities(); } else if ("county".equals(type)){ queryCounties(); } } }); } if ("city".equals(type)){ result = Utility.handleProvinceResponse(responseText); } if ("county".equals(type)){ result = Utility.handleProvinceResponse(responseText); } } }); } /*显示进度对话框*/ private void showProgressDialog() { if (progressDialog==null){ progressDialog = new ProgressDialog(getActivity()); progressDialog.setMessage("正在加载..."); progressDialog.setCanceledOnTouchOutside(false); } progressDialog.show(); } private void queryCounties() { titleText.setText(selectedCity.getCityName()); backButton.setVisibility(View.VISIBLE); countyList = DataSupport.where("cityid = ?", String.valueOf(selectedCity.getId())).find(County.class); if (countyList.size()>0){ dataList.clear(); for (County county:countyList){ dataList.add(county.getCountyName()); } adapter.notifyDataSetChanged(); listView.setSelection(0); currentLevel=LEVEL_COUNTY; } else { int provinceCode = selectedProvince.getProvinceCode(); int cityCode = selectedCity.getCityCode(); String address = "http://guolin.tech/api/china/"+provinceCode+"/"+cityCode; queryFromServer(address,"county"); } } /*全国所有的省，优先查询数据库，如果没有再去服务器查询*/ private void queryProvinces() { titleText.setText("中国"); Log.d("ChooseAreaFragment","查询省中..."); backButton.setVisibility(View.GONE); provinceList = DataSupport.findAll(Province.class); if (provinceList.size()>0){ dataList.clear(); for (Province province:provinceList){ dataList.add(province.getProvinceName()); } adapter.notifyDataSetChanged(); listView.setSelection(0); currentLevel = LEVEL_PROVINCE; } else { Log.d("ChooseAreaFragment","服务器查询省中..."); String address = "http://guolin.tech/api/china"; queryFromServer(address,"province"); } } private void closeProgressDialog() { if (progressDialog!=null){ progressDialog.dismiss(); } } } 2.这是报错日志 

从安卓模拟器路径用opencv读取图像失败

软件： android studio3.5 1. 我用 Device File Explorer上传了一张jpg图像到sdcard/Pictures文件夹中 2. 我试图用opencv 的imread函数读取这张图，结果显示读到的矩阵是空的，代码如下： String imPath = Environment.getExternalStorageDirectory() + "/Pictures/moose.jpg"; Mat im = Imgcodecs.imread(imPath, Imgcodecs.IMREAD_GRAYSCALE); if(im.empty()) tips += "Empty image... \n"; else { …… } 这是为什么啊？ 难道只能通过 Bitmap bitmap = BitmapFactory.decodeResource(MainActivity.this.getResources(),R.drawable.girl); Mat mat = new Mat(); Utils.bitmapToMat(bitmap,mat); 这种方式才能正常读图吗？ 我还想再读取一个本地的pb文件呢，就是读不对啊，请求指点

Android Studio创建虚拟机失败解决方法

1.创建虚拟机后，运行时出现错误对话框，错误内容如下： KVM is required to run this AVD. /dev/kvm is not found. Enable VT-x in your BIOS security settings, ensure that your Linux distro has working KVM module. 2.已经进入系统固件设置（BIOS）界面设置了“Intel (R) Virtualization Technology”项还是启动不了虚拟机。 3.然后又确认下载安装了Download Intel x86 Emulator Accelerator (HAXM installer)。 4.接着下载的SDK目录下找到intelhaxm-android.exe这个文件安装定并运行。但在安装是出现以下错误提示  5.之后再打开虚拟机还是提示KVM is required to run this AVD. /dev/kvm is not found. Enable VT-x in your BIOS security settings, ensure that your Linux distro has working KVM module. 6.出现上面这种情况怎么解决，虚拟机的问题

android studio启动genymotion失败

前几天还能正常启动，然后今天就初始化失败了，然后看了网上也不是没有reg.exe文件，请各位大神帮帮忙吧 9:21:03 Genymotion: Loading Genymotion library 9:21:03 Genymotion: Genymotion directory: E:\workSoftware\genymotion2.5.3\Genymotion 9:21:03 Genymotion: Trying to initialize engine 9:21:04 Genymotion: vboxPath: C:\Program Files\Oracle VM VirtualBox\VBoxManage.exe 9:21:04 Genymotion: Launch process: C:\Program Files\Oracle VM VirtualBox\VBoxManage.exe --version 9:21:04 Genymotion: Exception (C:\Program Files\Oracle VM VirtualBox\VBoxManage.exe) 9:21:04 Genymotion: Initialize Engine: failed 然后我又尝试使用android studio自带的模拟器，提示  这又是什么原因啊！！！！

正在学习android的第一行代码的coolweather遇到了点问题

ChooseAreaFragment代码 import android.app.ProgressDialog; import android.os.Bundle; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.AdapterView; import android.widget.ArrayAdapter; import android.widget.Button; import android.widget.ListView; import android.widget.TextView; import android.widget.Toast; import androidx.appcompat.widget.ButtonBarLayout; import androidx.fragment.app.Fragment; import com.example.coolweather.db.City; import com.example.coolweather.db.County; import com.example.coolweather.db.Province; import com.example.coolweather.util.HttpUtil; import com.example.coolweather.util.Utility; import org.litepal.crud.DataSupport; import java.io.IOException; import java.util.ArrayList; import java.util.List; import okhttp3.Call; import okhttp3.Callback; import okhttp3.Response; public class ChooseAreaFrament extends Fragment { public static final int LEVEL_PROVINCE = 0; public static final int LEVEL_CITY=1; public static final int LEVEL_COUNTY = 2; private ProgressDialog progressDialog; private TextView titleText; private Button backButton; private ListView listView; private ArrayAdapter<String> adapter; private List<String> dataList = new ArrayList<>(); /** * 省列表 */ private List<Province> provinceList; /** * 市列表 */ private List<City> cityList; /** * 县列表 */ private List<County>countyList; /** * 选中的省份 */ private Province selectedProvince; /** * 选中的城市 */ private City selectedCity; /** * 当前选中的级别 */ private int currentLevel; @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { View view = inflater.inflate(R.layout.choose_area,container,false); titleText = (TextView) view.findViewById(R.id.title_text); backButton = (Button) view.findViewById(R.id.back_button); listView = (ListView)view.findViewById(R.id.list_view); adapter = new ArrayAdapter<>(getContext(),android.R.layout.simple_list_item_1,dataList); listView.setAdapter(adapter); return view; } @Override public void onActivityCreated(Bundle savedInstanceState){ super.onActivityCreated(savedInstanceState); listView.setOnItemClickListener(new AdapterView.OnItemClickListener() { @Override public void onItemClick(AdapterView<?> parent, View view, int position, long id) { if(currentLevel == LEVEL_PROVINCE){ selectedProvince = provinceList.get(position); queryCities(); } else if (currentLevel == LEVEL_CITY) { selectedCity = cityList.get(position); queryCounties(); } } }); backButton.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { if (currentLevel == LEVEL_COUNTY) { queryCities(); } else if (currentLevel == LEVEL_CITY){ queryProvinces(); } } }); queryProvinces(); } /** * 查询全国所有的省，优先数据库查询，如果没有查询到再去服务器上查询 */ private void queryProvinces(){ titleText.setText("中国"); backButton.setVisibility(View.GONE); provinceList = DataSupport.findAll(Province.class); if (provinceList.size() > 0){ dataList.clear(); for (Province province : provinceList){ dataList.add(province.getProvinceName()); } adapter.notifyDataSetChanged(); listView.setSelection(0); currentLevel = LEVEL_PROVINCE; } else { String address = "http://guolin.tech/api/china"; queryFromServer(address,"province"); } } /** * 查询全国所有的城市，优先数据库查询，如果没有查询到再去服务器上查询 */ private void queryCities(){ titleText.setText(selectedProvince.getProvinceName()); backButton.setVisibility(View.VISIBLE); cityList = DataSupport.where("provinceid = ?",String.valueOf(selectedProvince. getId())).find(City.class); if(cityList.size() > 0){ dataList.clear(); for(City city : cityList){ dataList.add(city.getCityName()); } adapter.notifyDataSetChanged(); listView.setSelection(0); currentLevel = LEVEL_CITY; }else{ int provinceCode = selectedProvince.getProvinceCode(); String address = "http://guolin.tech/api/china/" + provinceCode; queryFromServer(address,"city"); } } /** * 查询全国所有的县，优先数据库查询，如果没有查询到再去服务器上查询 */ private void queryCounties(){ titleText.setText(selectedCity.getCityName()); backButton.setVisibility(View.VISIBLE); countyList = DataSupport.where("cityid = ?",String.valueOf(selectedCity. getId())).find(County.class); if(countyList.size() > 0 ){ dataList.clear(); for(County county : countyList){ dataList.add(county.getCountyName()); } adapter.notifyDataSetChanged(); listView.setSelection(0); currentLevel = LEVEL_COUNTY; }else{ int provinceCode = selectedProvince.getProvinceCode(); int cityCode = selectedCity.getCityCode(); String address = "http://guolin.tech/api/china/" + provinceCode + "/" + cityCode; queryFromServer(address,"county"); } } /** * 根据传入的地址和类型从服务器上查询省市县数据 */ private void queryFromServer(String address,final String type){ showProgressDialog(); HttpUtil.sendOkHttpRequest(address, new Callback() { @Override public void onResponse(Call call, Response response) throws IOException { String responseText = response.body().string(); boolean result = false; if("province".equals(type)){ result = Utility.handleProvinceResponse(responseText); } else if ("city".equals(type)){ result = Utility.handleCityResponse(responseText,selectedProvince.getId()); } else if ("county".equals(type)){ result = Utility.handleCountyResponse(responseText,selectedCity.getId()); } if (result){ getActivity().runOnUiThread(new Runnable() { @Override public void run() { closeProgressDialog(); if ("province".equals(type)){ queryProvinces(); } else if ("city".equals(type)){ queryCities(); } else if ("county".equals(type)) queryCounties(); } }); } } @Override public void onFailure(Call call, IOException e) { //通过runOnUiTread()方法回到主线程处理逻辑 getActivity().runOnUiThread(new Runnable() { @Override public void run() { closeProgressDialog(); Toast.makeText(getContext(),"加载失败",Toast.LENGTH_SHORT).show(); } }); } }); } /** * 显示进度对话框 */ private void showProgressDialog(){ if (progressDialog == null){ progressDialog = new ProgressDialog(getActivity()); progressDialog.setMessage("正在加载..."); progressDialog.setCanceledOnTouchOutside(false); } progressDialog.show(); } /** * 关闭进度对话框 */ private void closeProgressDialog(){ if (progressDialog != null){ progressDialog.dismiss(); } } Utility代码 import android.text.TextUtils; import com.example.coolweather.db.City; import com.example.coolweather.db.County; import com.example.coolweather.db.Province; import org.json.JSONArray; import org.json.JSONException; import org.json.JSONObject; public class Utility { /** * 解析和处理服务器返回的省级数据 */ public static boolean handleProvinceResponse(String response){ if (!TextUtils.isEmpty(response)){ try { JSONArray allProvinces = new JSONArray(response); for (int i = 0;i<allProvinces.length();i++){ JSONObject provinceObject = allProvinces.getJSONObject(i); Province province = new Province(); province.setProvinceName(provinceObject.getString("name")); province.setProvinceCode(provinceObject.getInt("id")); province.save(); } return true; } catch (JSONException e) { e.printStackTrace(); } } return false; } /** * 解析服务器和处理器返回的市级数据 */ public static boolean handleCityResponse(String response,int provinceId){ if(!TextUtils.isEmpty(response)){ try { JSONArray allCities = new JSONArray(response); for(int i=0;i<allCities.length();i++){ JSONObject cityObject = allCities.getJSONObject(i); City city = new City(); city.setCityName(cityObject.getString("name")); city.setCityCode(cityObject.getInt("id")); city.setProvinceId(provinceId); city.save(); } return true; } catch (JSONException e) { e.printStackTrace(); } } return false; } public static boolean handleCountyResponse(String response, int cityId){ if(TextUtils.isEmpty(response)){ try { JSONArray allCounties = new JSONArray(response); for(int i=0;i<allCounties.length();i++){ JSONObject countyObject = allCounties.getJSONObject(i); County county = new County(); county.setCountyName(countyObject.getString("name")); county.setWeatherId(countyObject.getString("weather_id")); county.setCityId(cityId); county.save(); } return true; } catch (JSONException e) { e.printStackTrace(); } } return false; } 复制代码 } HttpUtil代码 import okhttp3.OkHttpClient; import okhttp3.Request; public class HttpUtil { public static void sendOkHttpRequest(String address,okhttp3.Callback callback) { OkHttpClient client = new OkHttpClient(); Request request = new Request.Builder().url(address).build(); client.newCall(request).enqueue(callback); } 复制代码 } app apply plugin: 'com.android.application' android { compileSdkVersion 29 buildToolsVersion "29.0.2" defaultConfig { applicationId "com.example.coolweather" minSdkVersion 15 targetSdkVersion 29 versionCode 1 versionName "1.0" testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner" } buildTypes { release { minifyEnabled false proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro' } } sourceSets { main { jniLibs.srcDirs = ['libs'] } } } dependencies { implementation fileTree(dir: 'libs', include: ['*.jar']) implementation 'androidx.appcompat:appcompat:1.0.2' implementation 'androidx.constraintlayout:constraintlayout:1.1.3' implementation 'org.litepal.android:core:1.4.1' implementation 'com.squareup.okhttp3:okhttp:3.4.1' implementation 'com.google.code.gson:gson:2.7' implementation 'com.github.bumptech.glide:glide:3.7.0' testImplementation 'junit:junit:4.12' androidTestImplementation 'androidx.test:runner:1.2.0' androidTestImplementation 'androidx.test.espresso:espresso-core:3.2.0' } debug到这里就动不了

android studio：使用get方式提交数据到服务器，android客户端失败，jsp成功

一个简单的login案例，提交数据到服务器模拟登录，以前用的AS2.2，现在升级到3.2.1就不行了。之前一直用的是API19，没什么问题，现在API28一堆 could not find class 'android.support.v4.....'的错误，没有抛异常， 查了一下说要把AVD的API升级到28，结果还是不行，变成了这样 ``` 2019-03-04 15:44:50.346 1958-1970/system_process E/memtrack: Couldn't load memtrack module 2019-03-04 15:44:52.836 1958-1979/system_process E/memtrack: Couldn't load memtrack module 2019-03-04 15:44:53.258 1707-2033/? E/installd: Failed to delete /data/app/vmdl152882847.tmp: No such file or directory 2019-03-04 15:44:54.883 1702-2407/? E/SurfaceFlinger: ro.sf.lcd_density must be defined as a build property 2019-03-04 15:44:55.107 1702-2407/? E/SurfaceFlinger: ro.sf.lcd_density must be defined as a build property 2019-03-04 15:44:56.920 1958-2127/system_process E/TaskPersister: File error accessing recents directory (directory doesn't exist?). 2019-03-04 15:45:13.157 1958-1979/system_process E/memtrack: Couldn't load memtrack module ``` 并没有抛异常，点击按钮提交数据毫无反应，代码和之前一毛一样，网上也没有找到什么靠谱的方法，但jsp正常，控制台能打印服务器接收到的数据，请问各位大神是什么原因？

《第一行代码》的酷欧天气，点开省列表以后显示的还是省，而不是城市，这是再点一下省就直接闪退

Logcat如下 FATAL EXCEPTION: main Process: com.coolweather.android, PID: 11807 java.lang.IndexOutOfBoundsException: Index: 6, Size: 0 at java.util.ArrayList.get(ArrayList.java:411) at com.coolweather.android.ChooseAreaFragment$1.onItemClick(ChooseAreaFragment.java:76) at android.widget.AdapterView.performItemClick(AdapterView.java:310) at android.widget.AbsListView.performItemClick(AbsListView.java:1165) at android.widget.AbsListView$PerformClick.run(AbsListView.java:3137) at android.widget.AbsListView$3.run(AbsListView.java:4052) at android.os.Handler.handleCallback(Handler.java:751) at android.os.Handler.dispatchMessage(Handler.java:95) at android.os.Looper.loop(Looper.java:154) at android.app.ActivityThread.main(ActivityThread.java:6290) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:886) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:776) 代码如下 package com.coolweather.android; import android.app.ProgressDialog; import android.os.Bundle; import android.support.v4.app.Fragment; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.AdapterView; import android.widget.ArrayAdapter; import android.widget.Button; import android.widget.ListView; import android.widget.TextView; import android.widget.Toast; import com.coolweather.android.db.City; import com.coolweather.android.db.County; import com.coolweather.android.db.Province; import com.coolweather.android.util.HttpUtil; import com.coolweather.android.util.Utility; import org.litepal.crud.DataSupport; import java.io.IOException; import java.util.ArrayList; import java.util.List; import okhttp3.Call; import okhttp3.Callback; import okhttp3.Response; /** * Created by 王耀祖 on 2017/7/20. */ public class ChooseAreaFragment extends Fragment { public static final int LEVEL_PROVINCE = 0; public static final int LEVEL_CITY = 1; public static final int LEVEL_COUNTY = 2; private ProgressDialog progressDialog; private TextView titleText; private Button backButton; private ListView listView; private ArrayAdapter<String> adapter; private List<String> dataList = new ArrayList<>(); private List<Province> provinceList; private List<City> cityList; private List<County> countyList; private Province selectedProvince; private City selectedCity; private int currentLevel; @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { View view = inflater.inflate(R.layout.choose_area, container, false); titleText = (TextView) view.findViewById(R.id.title_text); backButton = (Button) view.findViewById(R.id.back_button); listView = (ListView) view.findViewById(R.id.list_view); adapter = new ArrayAdapter<String>(getContext(), android.R.layout.simple_list_item_1, dataList); listView.setAdapter(adapter); return view; } @Override public void onActivityCreated(Bundle savedInstanceState) { super.onActivityCreated(savedInstanceState); listView.setOnItemClickListener(new AdapterView.OnItemClickListener() { @Override public void onItemClick(AdapterView<?> parent, View view, int position, long id) { if (currentLevel == LEVEL_PROVINCE) { selectedProvince = provinceList.get(position); queryCities(); } else if (currentLevel == LEVEL_CITY) { selectedCity = cityList.get(position); queryCounties(); } } }); backButton.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { if(currentLevel==LEVEL_COUNTY){ queryCities(); } else if(currentLevel==LEVEL_CITY){ queryProvinces(); } } }); queryProvinces(); } private void queryProvinces(){ titleText.setText("中国"); backButton.setVisibility(View.GONE); provinceList= DataSupport.findAll(Province.class); if(provinceList.size()>0){ dataList.clear(); for(Province province:provinceList) dataList.add(province.getProvinceName()); adapter.notifyDataSetChanged(); listView.setSelection(0); currentLevel=LEVEL_PROVINCE; } else{ String address="http://guolin.tech/api/china"; queryFromServer(address,"province"); } } private void queryCities(){ titleText.setText(selectedProvince.getProvinceName()); backButton.setVisibility(View.VISIBLE); cityList=DataSupport.where("provinceid = ?",String.valueOf(selectedProvince .getId())).find(City.class); if(cityList.size()>0) { cityList.clear(); for(City city:cityList) dataList.add(city.getCityName()); adapter.notifyDataSetChanged(); listView.setSelection(0); currentLevel=LEVEL_CITY; } else{ int provinceCode=selectedProvince.getProvinceCode(); String address="http://guolin.tech/api/china/"+provinceCode; queryFromServer(address,"city"); } } private void queryCounties(){ titleText.setText(selectedCity.getCityName()); backButton.setVisibility(View.VISIBLE); countyList=DataSupport.where("cityid = ?",String.valueOf(selectedCity .getId())).find(County.class); if(countyList.size()>0) { countyList.clear(); for(County county:countyList) dataList.add(county.getCountyName()); adapter.notifyDataSetChanged(); listView.setSelection(0); currentLevel=LEVEL_COUNTY; } else{ int provinceCode=selectedProvince.getProvinceCode(); int cityCode=selectedCity.getCityCode(); String address="http://guolin.tech/api/china/"+provinceCode+"/"+cityCode; queryFromServer(address,"county"); } } private void queryFromServer(String address,final String type){ showProgressDialog(); HttpUtil.sendOkHttpRequest(address, new Callback() { @Override public void onFailure(Call call, IOException e) { getActivity().runOnUiThread(new Runnable() { @Override public void run() { closeProgressDialog(); Toast.makeText(getContext(), "加载失败", Toast.LENGTH_SHORT).show(); } }); } @Override public void onResponse(Call call, Response response) throws IOException { String responseText=response.body().string(); boolean result=false; if("province".equals(type)) result= Utility.handleProvinceResponse(responseText); else if("city".equals(type)) result=Utility.handleCityResponse(responseText,selectedProvince.getId()); else if("county".equals(type)) result=Utility.handleCountyResponse(responseText,selectedCity.getId()); if(result){ getActivity().runOnUiThread(new Runnable() { @Override public void run() { closeProgressDialog(); if("province".equals(type)) queryProvinces(); else if("city".equals(type)) queryCities(); else if("county".equals(type)) queryCounties(); } }); } } }); } private void showProgressDialog(){ if(progressDialog==null){ progressDialog=new ProgressDialog(getActivity()); progressDialog.setMessage("正在加载。。。"); progressDialog.setCanceledOnTouchOutside(false); } progressDialog.show(); } private void closeProgressDialog(){ if(progressDialog!=null) progressDialog.dismiss(); } }

为啥这个Toast一直是显示的红色的

package com.example.a23734.myapplication; import cn.bmob.v3.Bmob; import cn.bmob.v3.exception.BmobException; import cn.bmob.v3.listener.SaveListener; import android.app.Activity; import android.os.Bundle; import android.widget.Toast; import android.*; public class MainActivity extends Activity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); Bmob.initialize(this, "11c28913956ce3efb4ae4edffb0bce01"); Person p2 = new Person(); p2.setName("lucky"); p2.setAddress("北京海淀"); p2.save(new SaveListener<String>() { @Override public void done(String objectId,BmobException e) { if(e==null){ toast("添加数据成功，返回objectId为："+objectId); }else{ toast("创建数据失败：" + e.getMessage()); } } }); } } 

android ble蓝牙广播问题！！！！！！！！！！！！！！！！！！

使用ble蓝牙开发 在写入数据之后 设备返回的数据证明发送成功了 但是在广播中也会返回数据，我这边接收不到 使用别人的demo 可以接收到数据 这里有demo 哪位大哥帮忙看看代码有没有什么问题。 ``` package com.example.andysong.nuclearradiation.Ble; import android.bluetooth.BluetoothAdapter; import android.bluetooth.BluetoothDevice; import android.bluetooth.BluetoothGatt; import android.bluetooth.BluetoothGattCallback; import android.bluetooth.BluetoothGattCharacteristic; import android.bluetooth.BluetoothGattDescriptor; import android.bluetooth.BluetoothGattService; import android.bluetooth.BluetoothProfile; import android.companion.BluetoothDeviceFilter; import android.os.Bundle; import android.support.v7.app.AppCompatActivity; import android.support.v7.widget.LinearLayoutManager; import android.support.v7.widget.RecyclerView; import android.util.Log; import android.view.View; import android.widget.Button; import android.widget.LinearLayout; import android.widget.Toast; import com.example.andysong.nuclearradiation.Ble.Adapter.MyAdapter; import com.example.andysong.nuclearradiation.Ble.BleTool.MyBluetoothDevice; import com.example.andysong.nuclearradiation.Ble.Entity.BleData; import com.example.andysong.nuclearradiation.R; import com.example.andysong.nuclearradiation.Uitl.Progess.DialProgress; import java.io.UnsupportedEncodingException; import java.util.HashMap; import java.util.List; import java.util.Map; import java.util.Set; import java.util.UUID; public class BleActivityTest extends AppCompatActivity implements View.OnClickListener, MyAdapter.OnScan { private static final String TAG = BleActivityTest.class.getName(); private Button btn_scan; private Button btn_w; private RecyclerView rv_list; private MyAdapter myAdapter; private BluetoothAdapter bAdapter; private BluetoothGatt bluetoothGatt; private Map<String, UUID> uuidMap; //private UUID uNotify = UUID.fromString("6e400003-b5a3-f393-e0a9-e50e24dcca9e"); //private UUID N_Notify = UUID.fromString("0000ffe0-0000-1000-8000-00805f9b34fb"); private UUID N_Notify = UUID.fromString("00001000-0000-1000-8000-00805f9b34fb"); //private UUID uNotify = UUID.fromString("0000ffe4-0000-1000-8000-00805f9b34fb"); private UUID uNotify = UUID.fromString("00001002-0000-1000-8000-00805f9b34fb"); //private UUID uRead = UUID.fromString("6e400003-b5a3-f393-e0a9-e50e24dcca9e"); //private UUID uWrite = UUID.fromString("6e400003-b5a3-f393-e0a9-e50e24dcca9e"); //private UUID N_Write = UUID.fromString("0000ffe5-0000-1000-8000-00805f9b34fb"); private UUID N_Write = UUID.fromString("00001000-0000-1000-8000-00805f9b34fb"); private static final UUID CLIENT_CHARACTERISTIC_CONFIG = UUID.fromString( "00002902-0000-1000-8000-00805f9b34fb"); //private UUID uWrite = UUID.fromString("0000ffe9-0000-1000-8000-00805f9b34fb"); private UUID uWrite = UUID.fromString("00001001-0000-1000-8000-00805f9b34fb"); private String READ = "read"; private String WRITE = "write"; private String NOTICE = "notice"; private Button btn_r; private Button btn_n; private Button btn_c; private DialProgress dialProgress; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_ble); initView(); initData(); } private void initView() { btn_scan = findViewById(R.id.btn_scan); btn_w = findViewById(R.id.btn_w); btn_r = findViewById(R.id.btn_r); btn_n = findViewById(R.id.btn_n); btn_c = findViewById(R.id.btn_c); btn_scan.setOnClickListener(this); btn_w.setOnClickListener(this); btn_r.setOnClickListener(this); btn_n.setOnClickListener(this); btn_c.setOnClickListener(this); rv_list = findViewById(R.id.rv_list); rv_list.setLayoutManager(new LinearLayoutManager(this, LinearLayout.VERTICAL, false)); myAdapter = new MyAdapter(this); myAdapter.setOnScan(this); rv_list.setAdapter(myAdapter); dialProgress = findViewById(R.id.dialprog); } private void initData() { bAdapter = BluetoothAdapter.getDefaultAdapter(); uuidMap = new HashMap<>(); } @Override public void onClick(View v) { switch (v.getId()) { case R.id.btn_scan: scan(); break; case R.id.btn_w: writeData(); break; case R.id.btn_r: readData(); break; case R.id.btn_n: notifyData(); break; case R.id.btn_c: closeNotifyData(); break; } } /*关闭广播通知*/ private void closeNotifyData() { BluetoothGattCharacteristic characteristic = bluetoothGatt.getService(N_Notify).getCharacteristic(uNotify); BluetoothGattDescriptor descriptor = characteristic.getDescriptor(UUID.fromString("00002902-0000-1000-8000-00805f9b34fb")); descriptor.setValue(BluetoothGattDescriptor.DISABLE_NOTIFICATION_VALUE); bluetoothGatt.writeDescriptor(descriptor); } /*打开广播通知*/ private void notifyData() { BluetoothGattCharacteristic characteristic = bluetoothGatt.getService(N_Notify).getCharacteristic(uNotify); boolean b = bluetoothGatt.setCharacteristicNotification(characteristic, true); int originalWriteType = characteristic.getWriteType(); BluetoothGattDescriptor descriptor = characteristic.getDescriptor(CLIENT_CHARACTERISTIC_CONFIG); descriptor.setValue(BluetoothGattDescriptor.ENABLE_NOTIFICATION_VALUE); boolean b1 = bluetoothGatt.writeDescriptor(descriptor); characteristic.setWriteType(originalWriteType); } /*read 读取数据 返回的数据需要在监听事件接收*/ private void readData() { if (bluetoothGatt == null) { return; } BluetoothGattCharacteristic characteristic = bluetoothGatt.getService(UUID.fromString("00001000-0000-1000-8000-00805f9b34fb")). getCharacteristic(UUID.fromString("00001001-0000-1000-8000-00805f9b34fb")); bluetoothGatt.readCharacteristic(characteristic); } /*扫描设备*/ private void scan() { if (!bAdapter.isEnabled()) { Toast.makeText(this, "请打开蓝牙", Toast.LENGTH_SHORT).show(); return; } bAdapter.startLeScan(scanCallback); btn_scan.setText("扫描中"); btn_scan.setEnabled(false); } /*扫描到新的设备*/ private BluetoothAdapter.LeScanCallback scanCallback = new BluetoothAdapter.LeScanCallback() { @Override public void onLeScan(BluetoothDevice device, int rssi, byte[] scanRecord) { MyBluetoothDevice bluetoothDevice = new MyBluetoothDevice(device, rssi); addDevice(bluetoothDevice); // Log.e(TAG, "onLeScan: " + device.getAddress() + device.getName()); if (device.getAddress().equals("F6:6D:83:80:D6:8D")) { conn(bluetoothDevice); } //F6:6D:83:80:D6:8D } }; /*添加扫描的新设备*/ private void addDevice(MyBluetoothDevice bluetoothDevice) { List<MyBluetoothDevice> devices = myAdapter.getDevices(); for (MyBluetoothDevice device : devices) { if (device.getDevice().getAddress().equals(bluetoothDevice.getDevice().getAddress())) { return; } } myAdapter.upDate(bluetoothDevice); } /*item点击链接的方法*/ @Override public void conn(MyBluetoothDevice device) { bluetoothGatt = device.getDevice().connectGatt(this, false, mBluetoothGattCallback); } /*写数据 数据不会直接返回 需要在监听事件中回调*/ public void writeData() { if (bluetoothGatt == null) { return; } // bluetoothGatt.readRemoteRssi(); BluetoothGattCharacteristic characteristic = bluetoothGatt.getService(N_Write).getCharacteristic(uWrite); //characteristic.setValue("E5015101003420"); characteristic.setValue("EF52FFFAFFFF"); //characteristic.setWriteType(BluetoothGattCharacteristic.WRITE_TYPE_NO_RESPONSE); bluetoothGatt.writeCharacteristic(characteristic); } /*链接状态—ready—write-*/ BluetoothGattCallback mBluetoothGattCallback = new BluetoothGattCallback() { //链接状态更改时 @Override public void onConnectionStateChange(BluetoothGatt gatt, int status, int newState) { super.onConnectionStateChange(gatt, status, newState); if (newState == BluetoothProfile.STATE_CONNECTED) { gatt.discoverServices(); //查询支持的服务 bluetoothGatt = gatt; BleActivityTest.this.runOnUiThread(new Runnable() { @Override public void run() { btn_scan.setVisibility(View.GONE); btn_w.setVisibility(View.VISIBLE); btn_r.setVisibility(View.VISIBLE); btn_n.setVisibility(View.VISIBLE); btn_c.setVisibility(View.VISIBLE); } }); } else if (newState == BluetoothProfile.STATE_DISCONNECTED) { Log.e(TAG, "onConnectionStateChange: 断开"); BleActivityTest.this.runOnUiThread(new Runnable() { @Override public void run() { btn_scan.setEnabled(true); } }); } btn_scan.setText("扫描"); } //读取数据 @Override public void onCharacteristicRead(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic, int status) { super.onCharacteristicRead(gatt, characteristic, status); bluetoothGatt = gatt; if (status == BluetoothGatt.GATT_SUCCESS) { Log.e(TAG, "读取成功"); printALL(characteristic.getValue()); } else { Log.e(TAG, "读取失败"); } } //写出数据返回状态 @Override public void onCharacteristicWrite(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic, int status) { super.onCharacteristicWrite(gatt, characteristic, status); bluetoothGatt = gatt; if (status == BluetoothGatt.GATT_SUCCESS) { Log.e(TAG, "onCharacteristicWrite发送成功"); printALL(characteristic.getValue()); } else { Log.e(TAG, "onCharacteristicWrite发送失败"); } } /*一般情况是 给设备发送指令使用应该*/ @Override public void onDescriptorRead(BluetoothGatt gatt, BluetoothGattDescriptor descriptor, int status) { super.onDescriptorRead(gatt, descriptor, status); bluetoothGatt = gatt; if (status == BluetoothGatt.GATT_SUCCESS) { Log.e(TAG, "onDescriptorRead读取成功"); printALL(descriptor.getValue()); } else { Log.e(TAG, "onDescriptorRead读取失败"); } } /*一般情况是 给设备发送指令使用应该*/ @Override public void onDescriptorWrite(BluetoothGatt gatt, BluetoothGattDescriptor descriptor, int status) { super.onDescriptorWrite(gatt, descriptor, status); bluetoothGatt = gatt; if (status == BluetoothGatt.GATT_SUCCESS) { Log.e(TAG, "onDescriptorWrite发送成功"); printALL(descriptor.getValue()); } else { Log.e(TAG, "onDescriptorWrite发送失败"); } } /*接收通知 广播后 接收到的数据在这里*/ @Override public void onCharacteristicChanged(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic) { //super.onCharacteristicChanged(gatt, characteristic); 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Log.e(TAG, "读写属性: " + characteristic.getUuid()); for (BluetoothGattDescriptor bluetoothGattDescriptor:characteristic.getDescriptors()){ Log.e(TAG, "蓝牙描述符+++: " + bluetoothGattDescriptor.getUuid()); } } if ((characteristic.getProperties() & BluetoothGattCharacteristic.PROPERTY_WRITE) > 0) { uuidMap.put(WRITE, characteristic.getUuid()); Log.e(TAG, "写属性: " + characteristic.getUuid()); } if ((characteristic.getProperties() & BluetoothGattCharacteristic.PROPERTY_NOTIFY) > 0) { uuidMap.put(NOTICE, characteristic.getUuid()); Log.e(TAG, "通知属性: " + characteristic.getUuid()); for (BluetoothGattDescriptor bluetoothGattDescriptor : characteristic.getDescriptors()) { Log.e(TAG, "蓝牙描述符: " + bluetoothGattDescriptor.getUuid()); } } } } Set<String> strings = uuidMap.keySet(); for (String key : strings) { UUID uuid = uuidMap.get(key); Log.e(TAG, "list: " + uuid.toString()); } } private void printALL(byte[] b) { StringBuffer sb = new StringBuffer(); for (int i = 0; i < b.length; i++) { sb.append(Integer.toHexString(b[i]) + " "); } Log.e(TAG, "printALL--------: " + sb.toString()); } private void printALL2(final byte[] b) { Log.e(TAG, "printALL2--------: " + byteToString(b)); BleActivityTest.this.runOnUiThread(new Runnable() { @Override public void run() { dialProgress.setValue2(Double.parseDouble(formatString(byteToString(b)).getData())); } }); } private void printNotify(final byte[] b) { Log.e(TAG, "printNotify--------: " + byteToString(b)); BleActivityTest.this.runOnUiThread(new Runnable() { @Override public void run() { dialProgress.setValue2(Double.parseDouble(formatString(byteToString(b)).getData())); } }); } /*显示给客户*/ private String byteToString(byte[] b) { StringBuffer sb = new StringBuffer(); for (int i = 0; i < b.length; i++) { String s = String.valueOf(b[i]).replace("-", ""); String s1 = Integer.toHexString(Integer.valueOf(s)); if (i == 0 || i == 1) { char c = asciiToChar(Integer.valueOf(s)); sb.append(c + " "); continue; } else if (s1.length() == 1) { sb.append("0" + s1 + " "); continue; } sb.append(s1 + " "); } return sb.toString(); } /*ascii 转 字符*/ private char asciiToChar(int a) { return (char) a; } /*代码用来计算的数据*/ private BleData formatString(String v) { String value = v.replace(" ", ""); String command = value.substring(0, 2); String date = value.substring(2, 8); String company = value.substring(8, 10); String d = value.substring(10, 18); StringBuffer data = new StringBuffer(); boolean flag = true; for (int i = 0; i < d.length(); i++) { if (i == 0) { continue; } if (i % 2 != 0) { if (flag) { data.append(Integer.valueOf(d.substring(0, i + 1)) + "."); flag = false; } else { data.append(Integer.valueOf(d.substring(i - 1, i + 1))); } } } String crc = value.substring(18, value.length()); return new BleData(command, date, company, data.toString(), crc); } }; ```

运行报FATAL EXCEPTION: main。

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public static final int LEVEL_CITY=1; public static final int LEVEL_COUNTY=2; private ProgressDialog progressDialog; private TextView titleText; private Button backButton; private ListView listView; private ArrayAdapter<String> adapter; private List<String> dataList = new ArrayList<>(); private int currentLevel; //当前被选中的级别 private Province selectedProvince;//被选中的省份 private City selectedCity;//被选中的城市 private List<Province> provinceList;//省列表 private List<City> cityList;//市列表 private List<County> countyList ;//县列表 /*获取控件实例id*/ @Override public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) { Log.d("ChooseAreaFragment","onCreateView"); View view = inflater.inflate(R.layout.choose_area,container,false); titleText = (TextView)view.findViewById(R.id.title_text); //获取标题栏文本id backButton = (Button) view.findViewById(R.id.back_button); //获取标题栏id listView = (ListView)view.findViewById(R.id.list_view); //获取Item列表id //获取ArrayAdapter对象 adapter =new ArrayAdapter<>(getContext(), android.R.layout.simple_list_item_1, dataList); listView.setAdapter(adapter);//设置并初始化适配器 return view;//将视图返回 } /*点击事件集合*/ @Override public void onActivityCreated(@Nullable Bundle savedInstanceState) { Log.d("ChooseAreaFragment","onActivityCreated"); super.onActivityCreated(savedInstanceState); //列表任意一栏被点击，则... listView.setOnItemClickListener(new AdapterView.OnItemClickListener() { @Override public void onItemClick(AdapterView<?> parent, View view, int position, long id) { Log.d("ChooseAreaFragment","列表被点了的..."); if (currentLevel == LEVEL_PROVINCE){ //当前选中的级别为省份时 selectedProvince = provinceList.get(position); //当前点击为选中状态 queryCities();//查询市的方法 } else if (currentLevel == LEVEL_CITY){ selectedCity = cityList.get(position); queryCounties(); } } }); backButton.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { if (currentLevel == LEVEL_COUNTY){ queryCities(); } else if (currentLevel == LEVEL_CITY){ queryProvinces(); } } }); queryProvinces(); } private void queryCities() { titleText.setText(selectedProvince.getProvinceName()); 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Toast.makeText(getContext(),"加载失败",Toast.LENGTH_SHORT).show(); } }); } @Override public void onResponse(Call call, Response response) throws IOException { Log.d("ChooseAreaFragment","加载地区信息..."); String responseText = response.body().string(); boolean result = false; if ("province".equals(type)){ result = Utility.handleProvinceResponse(responseText); } else if ("city".equals(type)){ result = Utility.handleCityResponse(responseText,selectedProvince.getId()); } else if ("county".equals(type)){ result = Utility.handleCountyResponse(responseText, selectedCity.getId()); } if (result) { getActivity().runOnUiThread(new Runnable() { @Override public void run() { Log.d("ChooseAreaFragment","开启线程更新UI"); closeProgressDialog(); if ("province".equals(type)){ queryProvinces(); } else if ("city".equals(type)){ queryCities(); } else if ("county".equals(type)){ queryCounties(); } } }); } if ("city".equals(type)){ result = Utility.handleProvinceResponse(responseText); } if ("county".equals(type)){ result = Utility.handleProvinceResponse(responseText); } } }); } /*显示进度对话框*/ private void showProgressDialog() { if (progressDialog==null){ progressDialog = new ProgressDialog(getActivity()); progressDialog.setMessage("正在加载..."); progressDialog.setCanceledOnTouchOutside(false); } progressDialog.show(); } private void queryCounties() { titleText.setText(selectedCity.getCityName()); backButton.setVisibility(View.VISIBLE); countyList = DataSupport.where("cityid = ?", String.valueOf(selectedCity.getId())).find(County.class); if (countyList.size()>0){ dataList.clear(); for (County county:countyList){ dataList.add(county.getCountyName()); } adapter.notifyDataSetChanged(); listView.setSelection(0); currentLevel=LEVEL_COUNTY; } else { int provinceCode = selectedProvince.getProvinceCode(); int cityCode = selectedCity.getCityCode(); String address = "http://guolin.tech/api/china/"+provinceCode+"/"+cityCode; queryFromServer(address,"county"); } } /*全国所有的省，优先查询数据库，如果没有再去服务器查询*/ private void queryProvinces() { titleText.setText("中国"); Log.d("ChooseAreaFragment","查询省中..."); 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