1.运行TestProvider的时候报了Failed to find provider info for com.example.contentprvider3.Provider.UserProvider的错误,后来我把这种问题的解决方法都试了一遍依然不行,数据库是有的,也存入了数据,但还是获取不了ContentProvieder.
2.ContentProvider的代码
package com.example.contentprvider3.Provider;
import android.content.ContentProvider;
import android.content.ContentValues;
import android.content.UriMatcher;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.net.Uri;
import android.util.Log;
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import com.example.contentprvider3.utils.Constants;
import com.example.contentprvider3.Databasehelper.UserDatabasehelper;
import java.net.URI;
import javax.xml.transform.Result;
public class UserProvider extends ContentProvider {
private static final String SCHEMA="content://";
private static final String AUTHORITY="com.example.contentprvider3.UserProvider";
private static final String TAG = "UserProvider";
private static Uri uri_provider =Uri.parse(SCHEMA+AUTHORITY);
private UserDatabasehelper muserDatabaseHelper = null;
private static final int User_Match_Code = 1;
private static UriMatcher suriMatcher = new UriMatcher(UriMatcher.NO_MATCH);
static {
suriMatcher.addURI(AUTHORITY,null,User_Match_Code);
}
@Override
public boolean onCreate() {
muserDatabaseHelper = new UserDatabasehelper(getContext());
return false;
}
@Nullable
@Override
public Cursor query(@NonNull Uri uri, @Nullable String[] projection, @Nullable String selection, @Nullable String[] selectionArgs, @Nullable String sortOrder) {
//分配规则
int result = suriMatcher.match(uri);
Log.d(TAG,"RESULT-----"+ result);
if (result==User_Match_Code){
SQLiteDatabase db = muserDatabaseHelper.getReadableDatabase();
Cursor cursor = db.query(Constants.TABLE_NAME, projection, selection, selectionArgs, null, null, sortOrder);
}else{
//不匹配规则
throw new IllegalArgumentException("参数错误");
}
return null;
}
@Nullable
@Override
public String getType(@NonNull Uri uri) {
return null;
}
@Nullable
@Override
public Uri insert(@NonNull Uri uri, @Nullable ContentValues values) {
int result = suriMatcher.match(uri);
if(result==User_Match_Code) {
SQLiteDatabase db = muserDatabaseHelper.getWritableDatabase();
long id = db.insert(Constants.TABLE_NAME, null, values);
Uri uriresult = Uri.parse("content://com.example.contentprvider3.UserProvider"+id);
Log.d(TAG,"insert result ----"+id);
getContext().getContentResolver().notifyChange(uriresult,null);
return uriresult;
}else {
throw new IllegalArgumentException();
}
}
@Override
public int delete(@NonNull Uri uri, @Nullable String selection, @Nullable String[] selectionArgs) {
return 0;
}
@Override
public int update(@NonNull Uri uri, @Nullable ContentValues values, @Nullable String selection, @Nullable String[] selectionArgs) {
return 0;
}
}
3.ContentProvider的Manifest文件代码
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.contentprvider3">
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:roundIcon="@mipmap/ic_launcher_round"
android:supportsRtl="true"
android:theme="@style/Theme.ContentPrvider3">
<activity
android:name=".MainActivity"
android:exported="true">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<action android:name="android.intent.action.VIEW"/>
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<provider
android:exported="true"
android:authorities="com.example.contentprvider3.UserProvider"
android:grantUriPermissions="true"
android:name=".Provider.UserProvider">
</provider>
4.TestProvider部分的代码
package com.example.testprovider;
import androidx.appcompat.app.AppCompatActivity;
import android.content.ContentResolver;
import android.content.ContentValues;
import android.database.ContentObserver;
import android.database.Cursor;
import android.net.Uri;
import android.os.Bundle;
import android.os.Handler;
import android.util.Log;
import android.view.View;
public class MainActivity extends AppCompatActivity {
private static final String SCHEMA="content://";
private static final String AUTHORITY="com.example.contentprvider3.Provider.UserProvider";
private static Uri uri_provider =Uri.parse(SCHEMA+AUTHORITY);
private static final String TAG = "MainActivity";
public static final String FILED_ID = "id";
public static final String FILED_sex = "sex";
public static final String FILED_age = "age";
public static final String FILED_USERNAME = "USERNAME";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ContentResolver contentResolver =getContentResolver();
Uri uri =Uri.parse("content://com.example.contentprvider3.Provider.UserProvider");
contentResolver.registerContentObserver(uri, true, new ContentObserver(new Handler()) {
@Override
public void onChange(boolean selfChange) {
super.onChange(selfChange);
Log.d(TAG,"用户数据发生变化");
}
});
}
public void RemoteUser(View view) {
Log.d(TAG, "onClick");
try {
ContentResolver contentResolver = getContentResolver();
Cursor cursor = contentResolver.query(uri_provider, null, null, null, null);
Log.d(TAG, "cursor------"+cursor);
String[] columnNames2 = cursor.getColumnNames();
for (String columnName : columnNames2) {
Log.d(TAG, "columnName---" + columnName);
}
while (cursor.moveToNext()) {
Log.d(TAG, "------------");
for (String columnName : columnNames2) {
int columnname = cursor.getColumnIndex(columnName);
String value = cursor.getString(columnname);
Log.d(TAG, columnName + "------" + value);
Log.d(TAG, "----------------");
}
}
cursor.close();
}catch (Exception e){e.printStackTrace();
}
}
public void insert(View view){
ContentResolver contentResolver =getContentResolver();
Uri uri = Uri.parse("content://com.example.contentprvider3.Provider.UserProvider");
ContentValues values = new ContentValues();
values.put(FILED_age,19);
values.put(FILED_sex,"male");
values.put(FILED_USERNAME,"GE");
values.put(FILED_ID,2003);
contentResolver.insert(uri,values);
}
}
5.TestProvider的manifest文件代码
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.testprovider">
<uses-permission android:name="string"/>
<uses-permission android:name="string"/>
<queries>
<package android:name="com.example.contentprvider3"/>
<provider android:authorities="com.example.contentprvider3.UserProvider"/>
</queries>
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:roundIcon="@mipmap/ic_launcher_round"
android:supportsRtl="true"
android:theme="@style/Theme.TestProvider">
<activity
android:name=".MainActivity"
android:exported="true">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
