spring注入失败,@autowired不起作用

JDBC测试
测试

小白最近在学spring,请问@第二张图上的@autowired为啥不起作用啊??

2个回答

使用Spring Junit Test的时候应该要加上两个注解@RunWith(SpringRunner.class)和 @SpringBootTest;
你在你的JDBCTest类上加入这俩个注解应该可以解决这个问题。
关于这两个注释,https://blog.csdn.net/HeatDeath/article/details/79841526 这篇博文可以作为参考。
在以后使用Test时记得加入这俩个注视就好。

peace1024
peace1024 回复f1009976636: 客气,共同学习
大约一年之前 回复
f1009976636
f1009976636 谢谢您!
大约一年之前 回复

springmvc项目加上
@RunWith(SpringJUnit4ClassRunner.class)
或者
@RunWith(SpringRunner.class)

Csdn user default icon
上传中...
上传图片
插入图片
抄袭、复制答案,以达到刷声望分或其他目的的行为,在CSDN问答是严格禁止的,一经发现立刻封号。是时候展现真正的技术了!
其他相关推荐
spring mvc @Autowired 注入失败
配置如下: application-context.xml <?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:aop="http://www.springframework.org/schema/aop" xmlns:context="http://www.springframework.org/schema/context" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.0.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd" default-autowire="byName"> <context:annotation-config/> <import resource="classpath:spring-mvc/dispatcherContext-servlet.xml"/> </beans> dispatcherContext-servlet.xml <?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:p="http://www.springframework.org/schema/p" xmlns:context="http://www.springframework.org/schema/context" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd"> <!-- 使Controller中的@RequestMapping 生效--> <bean class="org.springframework.web.servlet.mvc.annotation.DefaultAnnotationHandlerMapping" /> <bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter"> <!-- 解决ajax调用中文乱码问题 --> <property name="messageConverters"> <list> <bean class="org.springframework.http.converter.json.MappingJacksonHttpMessageConverter"/> </list> </property> </bean> <bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver"> <!-- <property name="viewClass" value="org.springframework.web.servlet.view.JstlView" />--> <property name="suffix" value=".jsp" /> </bean> </beans> 被调用的类 package com.webservice.common; import java.util.List; import org.apache.http.HttpEntity; import org.apache.http.HttpResponse; import org.apache.http.HttpVersion; import org.apache.http.NameValuePair; import org.apache.http.client.HttpClient; import org.apache.http.client.entity.UrlEncodedFormEntity; import org.apache.http.client.methods.HttpPost; import org.apache.http.client.methods.HttpRequestBase; import org.apache.http.conn.scheme.PlainSocketFactory; import org.apache.http.conn.scheme.Scheme; import org.apache.http.conn.scheme.SchemeRegistry; import org.apache.http.conn.ssl.SSLSocketFactory; import org.apache.http.impl.client.DefaultHttpClient; import org.apache.http.impl.conn.PoolingClientConnectionManager; import org.apache.http.params.BasicHttpParams; import org.apache.http.params.CoreConnectionPNames; import org.apache.http.params.HttpParams; import org.apache.http.params.HttpProtocolParams; import org.apache.http.util.EntityUtils; import org.springframework.beans.factory.annotation.Autowired; import com.base.core.log4j.ILog4jManager; public class LocalHttpClient { private static HttpParams httpParams; private static PoolingClientConnectionManager connectionManager; /** * 最大连接数 */ public final static int MAX_TOTAL_CONNECTIONS = 100; /** * 每个路由最大连接数 */ public final static int MAX_ROUTE_CONNECTIONS = 20; /** * 连接超时时间 */ public final static int CONNECT_TIMEOUT = 10000; /** * 读取超时时间 */ public final static int READ_TIMEOUT = 10000; @Autowired private ILog4jManager log4jManager; static { // 设置组件参数, HTTP协议的版本,1.1/1.0/0.9 httpParams = new BasicHttpParams(); HttpProtocolParams.setVersion(httpParams, HttpVersion.HTTP_1_0); HttpProtocolParams.setUserAgent(httpParams, "Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.0)"); HttpProtocolParams.setUseExpectContinue(httpParams, true); //设置连接超时时间 httpParams.setParameter(CoreConnectionPNames.CONNECTION_TIMEOUT, CONNECT_TIMEOUT); httpParams.setParameter(CoreConnectionPNames.SO_TIMEOUT, READ_TIMEOUT); //设置访问协议 SchemeRegistry schreg = new SchemeRegistry(); schreg.register(new Scheme("http", 80, PlainSocketFactory.getSocketFactory())); schreg.register(new Scheme("https", 443, SSLSocketFactory.getSocketFactory())); //多连接的线程安全的管理器 connectionManager = new PoolingClientConnectionManager(schreg); connectionManager.setDefaultMaxPerRoute(MAX_ROUTE_CONNECTIONS); //每个主机的最大并行链接数 connectionManager.setMaxTotal(MAX_TOTAL_CONNECTIONS); //客户端总并行链接最大数 } /** * 获取httpClient * * @return */ public static HttpClient getHttpClient() { return new DefaultHttpClient(connectionManager, httpParams); } public String postMethod(String url,List<NameValuePair> list) throws Exception{ HttpPost httppost = new HttpPost(url); UrlEncodedFormEntity entity = new UrlEncodedFormEntity(list, "utf-8"); entity.toString(); httppost.setEntity(entity); HttpClient client = LocalHttpClient.getHttpClient(); HttpResponse httpResponse = client.execute(httppost); String xmlContent=EntityUtils.toString(httpResponse.getEntity()); String tex = new String(xmlContent.getBytes("ISO-8859-1"),"UTF-8"); //这个地方异常 log4jManager.infoCustomLog(getClass().getName(),"postMethod", tex);**** return tex; } } 单元测试类 package com.base.junit4support; import java.util.ArrayList; import java.util.List; import org.apache.http.NameValuePair; import org.apache.http.message.BasicNameValuePair; import org.junit.Test; import org.junit.runner.RunWith; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.test.context.ContextConfiguration; import org.springframework.test.context.junit4.AbstractJUnit4SpringContextTests; import org.springframework.test.context.junit4.SpringJUnit4ClassRunner; import com.base.core.Constants; import com.base.core.log4j.ILog4jManager; import com.webservice.common.LocalHttpClient; @RunWith(SpringJUnit4ClassRunner.class) @ContextConfiguration(locations = { "classpath:applicationConfiguration-context.xml" }) public class AbstractSpringJUnit4Support extends AbstractJUnit4SpringContextTests { @Autowired protected ILog4jManager log4jManager;; @Test public void say(){ System.out.println("000000"); //这个地方正常 log4jManager.debugCustomLog(getClass().getName(),"say", "正确"); LocalHttpClient localHttpClient = new LocalHttpClient(); List<NameValuePair> list = new ArrayList<NameValuePair>(); try { String xml = localHttpClient.postMethod(Constants.MOBILE_RECHARGE_URL, list); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } System.out.println("wwww"); } 求解。。。。
spring-boot2.16里面@Autowired 注入失败
@ConfigurationProperties 使用这个来生成配置类文件,但是总是注入失败 直接附上源码 [源码文件](https://pan.baidu.com/s/18h_U0Uy89SAcbnGNnqkR2g "")
SpringBoot中@Autowired注入bean失败:Error creating bean with name“XXXController”?
# 报错信息: ``` org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'authorizeController': Unsatisfied dependency expressed through field 'userMapper'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'userMapper' defined in file [E:\STS-WorkSpace\Forum\target\classes\com\Forum\mapper\UserMapper.class]: Invocation of init method failed; nested exception is java.lang.IllegalArgumentException: Property 'sqlSessionFactory' or 'sqlSessionTemplate' are required at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:643) ~[spring-beans-5.2.2.RELEASE.jar:5.2.2.RELEASE] at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:116) ~[spring-beans-5.2.2.RELEASE.jar:5.2.2.RELEASE] at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessProperties(AutowiredAnnotationBeanPostProcessor.java:399) ~[spring-beans-5.2.2.RELEASE.jar:5.2.2.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1422) ~[spring-beans-5.2.2.RELEASE.jar:5.2.2.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:594) ~[spring-beans-5.2.2.RELEASE.jar:5.2.2.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:517) ~[spring-beans-5.2.2.RELEASE.jar:5.2.2.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:323) ~[spring-beans-5.2.2.RELEASE.jar:5.2.2.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory$$Lambda$141/1866850137.getObject(Unknown Source) ~[na:na] at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) ~[spring-beans-5.2.2.RELEASE.jar:5.2.2.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:321) ~[spring-beans-5.2.2.RELEASE.jar:5.2.2.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202) ~[spring-beans-5.2.2.RELEASE.jar:5.2.2.RELEASE] at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:879) ~[spring-beans-5.2.2.RELEASE.jar:5.2.2.RELEASE] at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:878) ~[spring-context-5.2.2.RELEASE.jar:5.2.2.RELEASE] at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:550) ~[spring-context-5.2.2.RELEASE.jar:5.2.2.RELEASE] at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:141) ~[spring-boot-2.2.2.RELEASE.jar:2.2.2.RELEASE] at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:747) [spring-boot-2.2.2.RELEASE.jar:2.2.2.RELEASE] at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:397) [spring-boot-2.2.2.RELEASE.jar:2.2.2.RELEASE] at org.springframework.boot.SpringApplication.run(SpringApplication.java:315) [spring-boot-2.2.2.RELEASE.jar:2.2.2.RELEASE] at org.springframework.boot.SpringApplication.run(SpringApplication.java:1226) [spring-boot-2.2.2.RELEASE.jar:2.2.2.RELEASE] at org.springframework.boot.SpringApplication.run(SpringApplication.java:1215) [spring-boot-2.2.2.RELEASE.jar:2.2.2.RELEASE] at com.Forum.ForumApplication.main(ForumApplication.java:19) [classes/:na] Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'userMapper' defined in file [E:\STS-WorkSpace\Forum\target\classes\com\Forum\mapper\UserMapper.class]: Invocation of init method failed; nested exception is java.lang.IllegalArgumentException: Property 'sqlSessionFactory' or 'sqlSessionTemplate' are required at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1796) ~[spring-beans-5.2.2.RELEASE.jar:5.2.2.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:595) ~[spring-beans-5.2.2.RELEASE.jar:5.2.2.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:517) ~[spring-beans-5.2.2.RELEASE.jar:5.2.2.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:323) ~[spring-beans-5.2.2.RELEASE.jar:5.2.2.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory$$Lambda$141/1866850137.getObject(Unknown Source) ~[na:na] at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) ~[spring-beans-5.2.2.RELEASE.jar:5.2.2.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:321) ~[spring-beans-5.2.2.RELEASE.jar:5.2.2.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202) ~[spring-beans-5.2.2.RELEASE.jar:5.2.2.RELEASE] at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:276) ~[spring-beans-5.2.2.RELEASE.jar:5.2.2.RELEASE] at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1287) ~[spring-beans-5.2.2.RELEASE.jar:5.2.2.RELEASE] at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1207) ~[spring-beans-5.2.2.RELEASE.jar:5.2.2.RELEASE] at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:640) ~[spring-beans-5.2.2.RELEASE.jar:5.2.2.RELEASE] ... 20 common frames omitted Caused by: java.lang.IllegalArgumentException: Property 'sqlSessionFactory' or 'sqlSessionTemplate' are required at org.springframework.util.Assert.notNull(Assert.java:198) ~[spring-core-5.2.2.RELEASE.jar:5.2.2.RELEASE] at org.mybatis.spring.support.SqlSessionDaoSupport.checkDaoConfig(SqlSessionDaoSupport.java:123) ~[mybatis-spring-2.0.1.jar:2.0.1] at org.mybatis.spring.mapper.MapperFactoryBean.checkDaoConfig(MapperFactoryBean.java:73) ~[mybatis-spring-2.0.1.jar:2.0.1] at org.springframework.dao.support.DaoSupport.afterPropertiesSet(DaoSupport.java:44) ~[spring-tx-5.2.2.RELEASE.jar:5.2.2.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1855) ~[spring-beans-5.2.2.RELEASE.jar:5.2.2.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1792) ~[spring-beans-5.2.2.RELEASE.jar:5.2.2.RELEASE] ... 31 common frames omitted ``` # Mapper代码: ``` package com.Forum.mapper; import org.apache.ibatis.annotations.Insert; import org.apache.ibatis.annotations.Mapper; import com.Forum.Model.User; @Mapper public interface UserMapper{ @Insert("insert into user (name,account_id,token,gmt_create,gmt_modified) values (#{name},#{accountId}),#{token},#{gmtCreate},#{gmtModified}") public void insert(User user); } ``` # 启动代码: ``` package com.Forum; import org.mybatis.spring.annotation.MapperScan; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; import org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration; import org.springframework.context.annotation.ComponentScan; @SpringBootApplication(exclude = {DataSourceAutoConfiguration.class}) @ComponentScan(basePackages = {"com.Forum.*"}) @MapperScan(basePackages = {"com.Forum.mapper"}) public class ForumApplication { public static void main(String[] args) { SpringApplication.run(ForumApplication.class, args); } } ``` # Controller代码: ```package com.Forum.Controller; import java.util.UUID; import javax.servlet.http.HttpServletRequest; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.beans.factory.annotation.Value; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.RequestParam; import com.Forum.Dto.AccesstokenDTO; import com.Forum.Dto.GitHubUser; import com.Forum.Model.User; import com.Forum.Provider.GitHubProvider; import com.Forum.mapper.UserMapper; @Controller public class AuthorizeController{ @Autowired private GitHubProvider gitHubProvider; @Value("${github.client.id}") private String clientId; @Value("${github.client.secret}") private String clientSecret; @Value("${github.redirect.uri}") private String redirectUri; @Autowired public UserMapper userMapper; @GetMapping("/callback") public String callback(@RequestParam(name="code") String code, @RequestParam(name="state") String state, HttpServletRequest request ) { AccesstokenDTO accesstokenDTO = new AccesstokenDTO(); accesstokenDTO.setCode(code); accesstokenDTO.setRedirect_uri("redirectUri"); accesstokenDTO.setClient_id(clientId); accesstokenDTO.setClient_secret(clientSecret); accesstokenDTO.setState(state); String accessToken = gitHubProvider.getAccessToken(accesstokenDTO); GitHubUser githubUser = gitHubProvider.getUser(accessToken); if(githubUser != null) { // 登录成功,写cookie和session User user = new User(); user.setToken(UUID.randomUUID().toString()); user.setName(githubUser.getName()); user.setAccountId(String.valueOf(githubUser.getId())); user.setQmtCreate(System.currentTimeMillis()); user.setQmtModified(user.getQmtCreate()); userMapper.insert(user); request.getSession().setAttribute("user", githubUser); return "redirect:/"; // 去掉地址后缀 }else { // 登录失败,重新登录 return "redirect:/"; } } } ```
Spring框架中的Autowired注解,默认真的是按照ByType方式实现自动注入的吗?
在学习spring IOC的过程中,接触到@Autowired注解,资料上都是说默认是按照Bytype类型实现自动注入,但我的实际操作却发现是:先使用ByName,如果失败,再使用ByType。贴代码,求指点: Student类: ``` @Component public class Student { @Value("12") int age; @Value("lisa") String name; @Autowired School school; public Student(){} public Student(int age, String name, School school) { this.age = age; this.name = name; this.school = school; } @Override public String toString() { return "Student{" + "age=" + age + ", name='" + name + '\'' + ", school=" + school + '}'; } } ``` School类: ``` public class School { String name; String address; public School() { } public School(String name, String address) { this.name = name; this.address = address; } public String getName() { return name; } public void setName(String name) { this.name = name; } public String getAddress() { return address; } public void setAddress(String address) { this.address = address; } ``` xml文件 ``` <?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd"> <!--配置注解扫描器,base-package表示注解所在的包,目的是告诉spring框架去扫描指定包的注解--> <context:component-scan base-package="com.aipande.bao1"/> <bean id="school" class="com.aipande.bao1.School"> <property name="name" value="武汉大学21"/> </bean> <bean id="school03" class="com.aipande.bao1.School"> <property name="name" value="武汉大学21"/> </bean> <bean id="school02" class="com.aipande.bao1.School"> <property name="name" value="武汉大学"/> </bean> </beans> ``` 测试类: ``` public class AppTest01 { public static void main(String[] args) { /* * 创建spring容器对象 * spring框架在加载xml文件并创建spring容器对象的同时, * 就会将xml文件中配置的bean对象(作用域为singleton)一同创建,并将这些对象放置在spring容器中。 * */ String config = "applicationContext.xml"; ApplicationContext ctx = new ClassPathXmlApplicationContext(config); //使用getBean()方法获取bean对象 Student stu = (Student) ctx.getBean("student"); System.out.println(stu); } } ``` 结果输出: ``` Student{age=12, name='lisa', school=School{name='武汉大学21', address='null'}} ``` 问题: 如果按照Bytype方式获取bean对象,那上面就应该报错啊,因为sprig容器中存在多个同源bean对象,但是没有报错,说明是按照byName的方式注入。后来我将xml文件中id为school的bean对象删除,就出现了错误提示,说明此时是按照byType的方式注入。因此我有上面的疑问,求解
Autowired注入dao失败
配置如下,一直报错:org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'userService': Unsatisfied dependency expressed through field 'userDao'; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'com.lrto.module.dao.UserDao' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)},求各位大神指教![图片说明](https://img-ask.csdn.net/upload/201706/21/1498009009_951497.png)![图片说明](https://img-ask.csdn.net/upload/201706/21/1498009034_346371.png)![图片说明](https://img-ask.csdn.net/upload/201706/21/1498009085_509820.png)![图片说明](https://img-ask.csdn.net/upload/201706/21/1498009098_370800.png)![图片说明](https://img-ask.csdn.net/upload/201706/21/1498008872_125477.png)![图片说明](https://img-ask.csdn.net/upload/201706/21/1498008887_699488.png)
Spring注入失败求解答 谢谢!!!
我在myeclipse上使用的配置文件转到intellij上使用就报错了。。。 @Autowired private UserService userService; 不能注入,直接new userServiceImpl不报错 问题来了!!!! 我报错的是用maven创建的web项目,我不用maven创建就什么错都不报,请问怎么回事啊 exception org.springframework.web.util.NestedServletException: Request processing failed; nested exception is java.lang.NullPointerException org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:927) org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:822) javax.servlet.http.HttpServlet.service(HttpServlet.java:646) org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:796) javax.servlet.http.HttpServlet.service(HttpServlet.java:727) org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:88) org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) root cause java.lang.NullPointerException com.liu.demo.service.impl.UserServiceImpl.regist(UserServiceImpl.java:20) com.liu.demo.controller.UserController.look(UserController.java:19) sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) java.lang.reflect.Method.invoke(Method.java:601) org.springframework.web.method.support.InvocableHandlerMethod.invoke(InvocableHandlerMethod.java:219) org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:132) org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:104) org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandleMethod(RequestMappingHandlerAdapter.java:746) org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:687) org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:80) org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:925) org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:856) org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:915) org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:822) javax.servlet.http.HttpServlet.service(HttpServlet.java:646) org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:796) javax.servlet.http.HttpServlet.service(HttpServlet.java:727) org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:88) org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) note The full stack trace of the root cause is available in the Apache Tomcat/7.0.53 logs.
spring构造注入失败,init注入也失败,tomcat也不报错
init注入: @Service public class test { @PostConstruct public void server() { System.out.println("我只是为了进来一次"); e(); } public void e() { System.out.println("进到e"); } 构造注入: @Autowired public NettyServerBootstrap() throws InterruptedException { System.out.println("没进来啊"); bind(); } public void bind() throws InterruptedException { system.out.println("meijinlai"); } tomcat: 十月 16, 2015 2:49:57 下午 org.apache.catalina.core.AprLifecycleListener init 信息: The APR based Apache Tomcat Native library which allows optimal performance in production environments was not found on the java.library.path: C:\Program Files (x86)\Java\jdk1.7.0_05\bin;D:\Tomcat 7.0\bin 十月 16, 2015 2:49:58 下午 org.apache.coyote.AbstractProtocol init 信息: Initializing ProtocolHandler ["http-bio-8080"] 十月 16, 2015 2:49:58 下午 org.apache.coyote.AbstractProtocol init 信息: Initializing ProtocolHandler ["ajp-bio-8009"] 十月 16, 2015 2:49:58 下午 org.apache.catalina.startup.Catalina load 信息: Initialization processed in 1402 ms 十月 16, 2015 2:49:58 下午 org.apache.catalina.core.StandardService startInternal 信息: Starting service Catalina 十月 16, 2015 2:49:58 下午 org.apache.catalina.core.StandardEngine startInternal 信息: Starting Servlet Engine: Apache Tomcat/7.0.29 十月 16, 2015 2:49:58 下午 org.apache.catalina.startup.HostConfig deployDirectory 信息: Deploying web application directory D:\Tomcat 7.0\webapps\AppServer_1.3_netty_start 十月 16, 2015 2:49:59 下午 org.apache.catalina.loader.WebappClassLoader validateJarFile 信息: validateJarFile(D:\Tomcat 7.0\webapps\AppServer_1.3_netty_start\WEB-INF\lib\servlet-api.jar) - jar not loaded. See Servlet Spec 2.3, section 9.7.2. Offending class: javax/servlet/Servlet.class 十月 16, 2015 2:50:13 下午 org.apache.catalina.core.ApplicationContext log 信息: No Spring WebApplicationInitializer types detected on classpath 十月 16, 2015 2:50:13 下午 org.apache.catalina.core.ApplicationContext log 信息: Set web app root system property: 'webapp.root' = [D:\Tomcat 7.0\webapps\AppServer_1.3_netty_start\] 十月 16, 2015 2:50:13 下午 org.apache.catalina.core.ApplicationContext log 信息: Initializing log4j from [classpath:log4j.properties] 十月 16, 2015 2:50:13 下午 org.apache.catalina.core.ApplicationContext log 信息: Initializing Spring root WebApplicationContext 十月 16, 2015 2:50:28 下午 org.apache.catalina.startup.HostConfig deployDirectory 信息: Deploying web application directory D:\Tomcat 7.0\webapps\docs 十月 16, 2015 2:50:28 下午 org.apache.catalina.startup.HostConfig deployDirectory 信息: Deploying web application directory D:\Tomcat 7.0\webapps\manager 十月 16, 2015 2:50:28 下午 org.apache.catalina.startup.HostConfig deployDirectory 信息: Deploying web application directory D:\Tomcat 7.0\webapps\ROOT 十月 16, 2015 2:50:28 下午 org.apache.coyote.AbstractProtocol start 信息: Starting ProtocolHandler ["http-bio-8080"] 十月 16, 2015 2:50:28 下午 org.apache.coyote.AbstractProtocol start 信息: Starting ProtocolHandler ["ajp-bio-8009"] 十月 16, 2015 2:50:28 下午 org.apache.catalina.startup.Catalina start 信息: Server startup in 30570 ms tomcat没报错,上面那两个报错没有关系的,对程序没影响。 注意:项目service注入是成功的,resource也是成功的, 就是上面两个注入是失败的 附application.xml:<context:component-scan base-package="com"/> 文件都在com.AppServer.action bean xxxx目录下
SpringMVC Autowired 注入失败 求大神帮忙
我用的是SpringMVC和Mybatis来做的 就是在customerService那注入失败 ![图片说明](https://img-ask.csdn.net/upload/201708/24/1503560242_572597.png) ![图片说明](https://img-ask.csdn.net/upload/201708/24/1503560265_566745.png) ![图片说明](https://img-ask.csdn.net/upload/201708/24/1503560274_428788.png) WARN [localhost-startStop-1] - Exception encountered during context initialization - cancelling refresh attempt org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'customerController': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private com.java.service.CustomerService com.java.controller.CustomerController.customerService; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [com.java.service.CustomerService] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)} at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:334) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1202) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:537) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:476) at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:302) at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230) at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:298) at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:193) at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:762) at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:757) at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:480) at org.springframework.web.servlet.FrameworkServlet.configureAndRefreshWebApplicationContext(FrameworkServlet.java:663) at org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:629) at org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:677) at org.springframework.web.servlet.FrameworkServlet.initWebApplicationContext(FrameworkServlet.java:548) at org.springframework.web.servlet.FrameworkServlet.initServletBean(FrameworkServlet.java:489) at org.springframework.web.servlet.HttpServletBean.init(HttpServletBean.java:136) at javax.servlet.GenericServlet.init(GenericServlet.java:158) at org.apache.catalina.core.StandardWrapper.initServlet(StandardWrapper.java:1183) at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1099) at org.apache.catalina.core.StandardWrapper.load(StandardWrapper.java:989) at org.apache.catalina.core.StandardContext.loadOnStartup(StandardContext.java:4913) at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5223) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:752) at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:728) at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:734) at org.apache.catalina.startup.HostConfig.deployDirectory(HostConfig.java:1107) at org.apache.catalina.startup.HostConfig$DeployDirectory.run(HostConfig.java:1841) at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) at java.util.concurrent.FutureTask.run(FutureTask.java:266) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) at java.lang.Thread.run(Thread.java:745) Caused by: org.springframework.beans.factory.BeanCreationException: Could not autowire field: private com.java.service.CustomerService com.java.controller.CustomerController.customerService; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [com.java.service.CustomerService] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)} at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:558) at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:87) at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:331) ... 33 more Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [com.java.service.CustomerService] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)} at org.springframework.beans.factory.support.DefaultListableBeanFactory.raiseNoSuchBeanDefinitionException(DefaultListableBeanFactory.java:1308) at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1054) at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:949) at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:530) ... 35 more
Spring整合Mybatis关于Dao注入失败的问题求解
抛出异常 org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'adminService': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private pers.zww.grad.dao.IAdminDao pers.zww.grad.service.impl.AdminServiceImpl.adminDao; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [pers.zww.grad.dao.IAdminDao] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true), @org.springframework.beans.factory.annotation.Qualifier(value=adminDao)} 此为自动生成的Mapper,我加了注解@Repository package pers.zww.grad.dao; import org.springframework.stereotype.Repository; import pers.zww.grad.vo.Admin; @Repository("adminDao") public interface IAdminDao { int deleteByPrimaryKey(String id); int insert(Admin record); int insertSelective(Admin record); Admin selectByPrimaryKey(String id); int updateByPrimaryKeySelective(Admin record); int updateByPrimaryKey(Admin record); Integer getCountByName(String name); Integer getCountByNameAndPass(String name,String password); } 这是Service里面注入 package pers.zww.grad.service.impl; 、、、 @Service("adminService") public class AdminServiceImpl implements IAdminService { @Autowired @Qualifier("adminDao") private IAdminDao adminDao; @Override public int deleteByPrimaryKey(String id) { // TODO Auto-generated method stub return 0; } 配置文件都已扫描过了,而且相关mybatis的如下: <!-- spring和MyBatis完美整合,不需要mybatis的配置映射文件 --> <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean"> <property name="dataSource" ref="dataSource" /> <!-- 自动扫描mapping.xml文件 --> <property name="mapperLocations" value="classpath:pers/zww/grad/mapping/*.xml"></property> </bean> <!-- DAO接口所在包名,Spring会自动查找其下的类 --> <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer"> <property name="basePackage" value="pers.zww.grad.dao" /> <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"></property> </bean>
@Autowired注入为null,空指针异常。
Spring mvc + hibernate 的框架中,在非Controller下使用@Autowired注入失败,空指针异常。 配置文件中已经加入了如下的内容 <context:component-scan base-package="com.cnwaterinfo.csp.*"/> <!-- 使用annotation 自动注册bean,并保证@Required,@Autowired的属性被注入 --> <context:component-scan base-package="com.cnwaterinfo.csp."> <context:exclude-filter type="regex" expression=".*.*Controller$" /> </context:component-scan> Service类: @Service("realtimeDataService") @Transactional public class RealtimeDataServiceImpl implements RealtimeDataService { @Autowired private RealtimeDataDao rdd; .... 在非Controller下 public class NetWorkPascalRealtimeDataHandler { private final static Logger log = Logger .getLogger(NetWorkPascalRealtimeDataHandler.class); @Autowired private RealtimeDataService realtimeDataService; ..... 此时realtimeDataService为NULL,调用任何方法都会空指针异常 何解?
Spring boot JdbcTemplate 自动注入失败
``` @Repository public class UserDataImpl implements UserData { @Autowired JdbcTemplate jdbcTemplate; } ``` ``` 2017-07-06 17:37:20.523 ERROR 2990 --- [nio-8080-exec-3] o.a.c.c.C.[.[.[/].[dispatcherServlet] : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is java.lang.NullPointerException] with root cause java.lang.NullPointerException: null at com.marnon.service.UserService.userCheck(UserService.java:30) ~[classes/:na] at com.marnon.controller.MyController.logIn(MyController.java:45) ~[classes/:na] at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_91] at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_91] at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_91] at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_91] at org.springsource.loaded.ri.ReflectiveInterceptor.jlrMethodInvoke(ReflectiveInterceptor.java:1426) ~[springloaded-1.2.6.RELEASE.jar:1.2.6.RELEASE] at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:205) ~[spring-web-4.3.9.RELEASE.jar:4.3.9.RELEASE] at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:133) ~[spring-web-4.3.9.RELEASE.jar:4.3.9.RELEASE] at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:97) ~[spring-webmvc-4.3.9.RELEASE.jar:4.3.9.RELEASE] at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:827) ~[spring-webmvc-4.3.9.RELEASE.jar:4.3.9.RELEASE] at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:738) ~[spring-webmvc-4.3.9.RELEASE.jar:4.3.9.RELEASE] at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85) ~[spring-webmvc-4.3.9.RELEASE.jar:4.3.9.RELEASE] at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:967) ~[spring-webmvc-4.3.9.RELEASE.jar:4.3.9.RELEASE] at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:901) ~[spring-webmvc-4.3.9.RELEASE.jar:4.3.9.RELEASE] at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970) ~[spring-webmvc-4.3.9.RELEASE.jar:4.3.9.RELEASE] at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:872) ~[spring-webmvc-4.3.9.RELEASE.jar:4.3.9.RELEASE] at javax.servlet.http.HttpServlet.service(HttpServlet.java:661) ~[tomcat-embed-core-8.5.15.jar:8.5.15] at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846) ~[spring-webmvc-4.3.9.RELEASE.jar:4.3.9.RELEASE] at javax.servlet.http.HttpServlet.service(HttpServlet.java:742) ~[tomcat-embed-core-8.5.15.jar:8.5.15] at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) ~[tomcat-embed-core-8.5.15.jar:8.5.15] at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.15.jar:8.5.15] at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) ~[tomcat-embed-websocket-8.5.15.jar:8.5.15] at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.15.jar:8.5.15] at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.15.jar:8.5.15] at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99) ~[spring-web-4.3.9.RELEASE.jar:4.3.9.RELEASE] at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-4.3.9.RELEASE.jar:4.3.9.RELEASE] at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.15.jar:8.5.15] at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.15.jar:8.5.15] at org.springframework.web.filter.HttpPutFormContentFilter.doFilterInternal(HttpPutFormContentFilter.java:105) ~[spring-web-4.3.9.RELEASE.jar:4.3.9.RELEASE] at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-4.3.9.RELEASE.jar:4.3.9.RELEASE] at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.15.jar:8.5.15] at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.15.jar:8.5.15] at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:81) ~[spring-web-4.3.9.RELEASE.jar:4.3.9.RELEASE] at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-4.3.9.RELEASE.jar:4.3.9.RELEASE] at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.15.jar:8.5.15] at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.15.jar:8.5.15] at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:197) ~[spring-web-4.3.9.RELEASE.jar:4.3.9.RELEASE] at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-4.3.9.RELEASE.jar:4.3.9.RELEASE] at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.15.jar:8.5.15] at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.15.jar:8.5.15] at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:198) ~[tomcat-embed-core-8.5.15.jar:8.5.15] at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) [tomcat-embed-core-8.5.15.jar:8.5.15] at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:478) [tomcat-embed-core-8.5.15.jar:8.5.15] at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140) [tomcat-embed-core-8.5.15.jar:8.5.15] at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:80) [tomcat-embed-core-8.5.15.jar:8.5.15] at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87) [tomcat-embed-core-8.5.15.jar:8.5.15] at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342) [tomcat-embed-core-8.5.15.jar:8.5.15] at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:799) [tomcat-embed-core-8.5.15.jar:8.5.15] at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66) [tomcat-embed-core-8.5.15.jar:8.5.15] at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:861) [tomcat-embed-core-8.5.15.jar:8.5.15] at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1455) [tomcat-embed-core-8.5.15.jar:8.5.15] at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) [tomcat-embed-core-8.5.15.jar:8.5.15] at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [na:1.8.0_91] at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [na:1.8.0_91] at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-8.5.15.jar:8.5.15] at java.lang.Thread.run(Thread.java:745) [na:1.8.0_91] ```
spring mvc注入controller失败找不到原因
运行不报错,根目录下的文件可以访问。但是访问不了Controller,打断点运行也进不去, 访问http://localhost:8081/rest/itemcat/list就404找不到页面,求大神解救。 这是springMVC配置文件 ``` <?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:p="http://www.springframework.org/schema/p" xmlns:context="http://www.springframework.org/schema/context" xmlns:mvc="http://www.springframework.org/schema/mvc" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd"> <context:component-scan base-package="com.taotao.rest.controller" /> <mvc:annotation-driven /> <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"> <property name="prefix" value="/WEB-INF/jsp/" /> <property name="suffix" value=".jsp" /> </bean> </beans> ``` 这是Controller层 ``` package com.taotao.rest.controller; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.http.MediaType; import org.springframework.http.converter.json.MappingJacksonValue; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.ResponseBody; import com.taotao.common.utils.JsonUtils; import com.taotao.rest.pojo.CatResult; import com.taotao.rest.service.ItemCatService; /** * 商品分类列表 * <p>Title: ItemCatController</p> * <p>Description: </p> * <p>Company: www.itcast.com</p> */ @Controller public class ItemCatController { @Autowired private ItemCatService itemCatService; /*@RequestMapping(value="/itemcat/list", produces=MediaType.APPLICATION_JSON_VALUE + ";charset=utf-8") @ResponseBody public String getItemCatList(String callback) { CatResult catResult = itemCatService.getItemCatList(); //把pojo转换成字符串 String json = JsonUtils.objectToJson(catResult); //拼装返回值 String result = callback + "(" + json + ");"; return result; }*/ @RequestMapping("/itemcat/list") @ResponseBody public Object getItemCatList(String callback) { CatResult catResult = itemCatService.getItemCatList(); MappingJacksonValue mappingJacksonValue = new MappingJacksonValue(catResult); mappingJacksonValue.setJsonpFunction(callback); return mappingJacksonValue; } } ``` 这是web.xml ``` <?xml version="1.0" encoding="UTF-8"?> <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" id="taotao" version="2.5"> <display-name>taotao-portal</display-name> <welcome-file-list> <welcome-file>index.html</welcome-file> <welcome-file>index.htm</welcome-file> <welcome-file>index.jsp</welcome-file> <welcome-file>default.html</welcome-file> <welcome-file>default.htm</welcome-file> <welcome-file>default.jsp</welcome-file> </welcome-file-list> <!-- 加载spring容器 --> <context-param> <param-name>contextConfigLocation</param-name> <param-value>classpath:spring/applicationContext-*.xml</param-value> </context-param> <listener> <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class> </listener> <!-- 解决post乱码 --> <filter> <filter-name>CharacterEncodingFilter</filter-name> <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class> <init-param> <param-name>encoding</param-name> <param-value>utf-8</param-value> </init-param> </filter> <filter-mapping> <filter-name>CharacterEncodingFilter</filter-name> <url-pattern>/*</url-pattern> </filter-mapping> <!-- springmvc的前端控制器 --> <servlet> <servlet-name>taotao-portal</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <!-- contextConfigLocation不是必须的, 如果不配置contextConfigLocation, springmvc的配置文件默认在:WEB-INF/servlet的name+"-servlet.xml" --> <init-param> <param-name>contextConfigLocation</param-name> <param-value>classpath:spring/springmvc.xml</param-value> </init-param> <load-on-startup>1</load-on-startup> </servlet> <servlet-mapping> <servlet-name>taotao-portal</servlet-name> <!-- 伪静态化 --> <url-pattern>*.html</url-pattern> </servlet-mapping> </web-app> ```
为什么spring注解注入失败?
spring版本3.0.5 @Component public class IndexFacade { @Autowired private UserService userService; 其中 userService访问时是null 注解扫描的包 <!-- 扫描指定package下所有带有如@controller,@services,@resource,并把所注释的注册为Spring Beans --> <context:component-scan base-package="org.yanb.test" use-default-filters="false"> <context:include-filter type="regex" expression="org.test.main.control.*Control"/> <context:include-filter type="regex" expression="org.test.main.facade.*Facade"/> <context:include-filter type="regex" expression="org.test.main.service.*Service"/> <context:include-filter type="regex" expression="org.test.main.dao.impl.*Impl"/> <!--不扫描<context:exclude-filter type="annotation" expression="org.springframework.stereotype.Controller" /> --> </context:component-scan> 奇怪的是control可以注入进来userService @Controller public class IndexControl extends BaseController { @Autowired private IndexFacade indexFacade; @Autowired private UserService userService; 求大神帮解决下吧谢谢,我没分了抱歉
@controller @Autowired 对@Transactional 不起作用
经过进一步了解得知 @Transactional注解需要<tx:annotation-driven transaction-manager="jpaTxManager" />配置 但是前提是只对已经注入的bean起作用,(配置在xml中的bean) 但是对@Controller这样未经xml配置的bean却不起作用,如何解决这个问题呢 原问题:我使用JPA集成spring的配置 [code="java"]<bean id="jpaTxManager" class="org.springframework.orm.jpa.JpaTransactionManager"> <property name="entityManagerFactory" ref="entityManagerFactory" /> <property name="dataSource" ref="dataSource" /> </bean> <tx:annotation-driven transaction-manager="jpaTxManager" />[/code] 然后只有在每个daoImpl前加@Transactional 增删改才可以生效 如果不加@Transactional 则调用增删改方法不会生效 [code="java"] @Transactional class UserDaoImpl{ public void save(){ xxxx } } class RoleDaoImpl{ public void save(){ xxxx } } [/code] 问题: 我在另一个类中调用Dao 如: class UserController{ UserDao userDao; RoleDao roleDao; @Transactional public void saveUserRole(){ userDao.save(xxx); roleDao.save(yyy); } } 但是controller中两个save方法仍然是分别得事务,比如userDao插入失败,但是roleDao却插入成功 如何让userDao 与 roleDao 同时成功,同时回滚 @Transactional 这个具体用法我搜过相关配置资料了,一一试过都不大管用, 不知道这个的事务处理机制是怎样的。。。
NettyServer注入失败,无法交给IOC托管
netty服务端需要跟DB交互 ``` @Component("nettyServer") public class MyServerHandler extends SimpleChannelInboundHandler<String> { @Autowired private CoreUserMapper userMapper; @Autowired private CoreRounduserMapper rounduserMapper; ``` 此处的俩mapper都为null 但是我在MyServerHandler里写个测试方法引用mapper内的方法,新建一个Controller然后@autowired注入这个MyServerHandler,断点进来这个mapper就不是空了,所以不是扫描路径的问题,我试过用service注解和@Component注解,还有在xml里bean注入都无法单独托管这个MyServerHandler
求助:springboot中接口和实现类不在同一个jar中,@Autowired失败
# 1.demo ## 1-1.接口定义 包名:com.example.demo 接口:ITest ``` package com.example.demo; public interface ITest { void find(); } ``` ## 1.2.接口使用 ``` @Autowired @Qualifier("myTest2") // ←自动注入不同的实现类 private ITest itest; // 调用实现类的方法 itest.find(); ``` ## 1.3.同一jar中定义实现类 ``` package com.example.demo; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.stereotype.Component; @Component public class MyTest2 implements ITest { private static final Logger LOGGER = LoggerFactory.getLogger(MyTest2.class); @Override public void find() { LOGGER.info("MyTest2#find"); } } ``` # 2.demo01 在其他jar中定义实现类【**包名相同**】 ``` package com.example.demo; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.stereotype.Component; @Component public class MyTest implements ITest { private static final Logger LOGGER = LoggerFactory.getLogger(MyTest.class); @Override public void find() { LOGGER.info("MyTest#find"); } } ``` **注)Springboot入口类:** ``` @SpringBootApplication(scanBasePackages = { "com.example" }) public class DemoApplication { public static void main(String[] args) { SpringApplication.run(DemoApplication.class, args); } } ``` 然后修改上面【1.2.接口使用】中@Qualifier的实现类,运行后发现: 1.@Qualifier("myTest") -------> 运行失败,错误如下: > *************************** > APPLICATION FAILED TO START > *************************** > > Description: > > Field itest in com.example.demo.MyRunner required a bean of type 'com.example.demo.ITest' that could not be found. > > > Action: > > Consider defining a bean of type 'com.example.demo.ITest' in your configuration. 2.@Qualifier("myTest2") -------> 运行成功
springBoot使用注解注入失败
**useMapper的xml文件** ``` <mapper namespace="com.auto.dao.UserMapper"> <select id="findByName" parameterType="String" resultType="User"> select * from t_user where username=#{username} </select> </mapper> ``` **mapper接口代码** ``` public interface UserMapper { public User findByName(String username); } ``` **springboot启动类的代码** ``` @SpringBootApplication @MapperScan("com.auto.dao") public class App { public static void main(String[] args) { SpringApplication.run(App.class,args); } } ``` **pom.xml文件配置** ``` <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>1.5.10.RELEASE</version> </parent> <groupId>com.auto</groupId> <artifactId>MavenDay01</artifactId> <version>0.0.1-SNAPSHOT</version> <properties> <java.version>1.8</java.version> </properties> <dependencies> <dependency> <!-- spirngBoot启动器 --> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <!-- jstl --> <groupId>javax.servlet</groupId> <artifactId>jstl</artifactId> </dependency> <dependency> <groupId>org.apache.tomcat.embed</groupId> <artifactId>tomcat-embed-jasper</artifactId> </dependency> <dependency> <groupId>org.mybatis.spring.boot</groupId> <artifactId>mybatis-spring-boot-starter</artifactId> <version>1.3.1</version> </dependency> ``` **user的实体类** ``` @Repository public class User { private String username; private String password; public String getUsername() { return username; } public void setUsername(String username) { this.username = username; } public String getPassword() { return password; } public void setPassword(String password) { this.password = password; } @Override public String toString() { return "User [username=" + username + ", password=" + password + "]"; } } ``` **这是properties的配置文件** ``` spring.datasource.driverClassName=com.mysql.jdbc.Driver spring.datasource.url=jdbc:mysql://localhost:3306/mysql spring.datasource.username=root spring.datasource.password=123456 spring.datasource.type=com.alibaba.druid.pool.DruidDataSource mybatis.type-aliases-package=com.auto.entity 实体类和mapper.xml文件都在这包里面 server.port=9090 spring.mvc.view.prefix=/WEB-INF/jsp/ spring.mvc.view.suffix=.jsp ``` **我写了个service接口,然后写了个实现类重写findByName方法返回userMapper中方法,在实现类中注入了userMapper接口,这里无法使用@Autowired注入** ``` @Service @Transactional public class UserServiceImpl implements UserService{ @Resource UserMapper userMapper; @Override public User findByName(String username) { return userMapper.findByName(username); } } ``` **报错** ``` org.apache.ibatis.binding.BindingException: Invalid bound statement (not found): com.auto.dao.UserMapper.findByName ``` 总是报找不到接口,加上注解标记也没用,换成在接口上用@mapper注解也不行,是什么问题,我在网上看说有什么依赖包冲突问题,但我换了几个版本也不行; **问题已经解决:** 问题出在没有在properties文件中添加mapper.xml文件的扫描路径 解决办法:在properties文件中加上 mybatis.mapper-locations=com/.../.../*.xml 这里是mapper.xml文件的路径
Spring将子类自动注入父类失败
``` @Controller public class LoginController{ @Resource(name="loginService") private IService loginService; @RequestMapping("/login") @Autowired public ModelAndView index(BaseClassDo logindo){ LoginDo ll= (LoginDo) logindo; ModelAndView mv = new ModelAndView(); System.out.println(logindo); // mv = loginService.doService(logindo); mv.setViewName("login"); return mv; } } ``` 上面index方法中,初始化的时候使用断点显示logindo是自动注入成功的,显示的是子类的字段,但是之后从页面jsp跳转过来后,注入失败,显示的只有父类的两个字段,而且强转失败java.lang.ClassCastException,难道从前台传到后天还有什么讲究吗 使用@autowrie或@Resource都试过,没有用 下面是实体表 **父类** ``` public class BaseClassDo { /** * 业务类型 */ private String ywtype; /** * 业务状态 */ private String ywstate; getset方法略 ``` **子类** ``` @Component("loginDo") public class LoginDo extends BaseClassDo { private String job_id; private int worker_id; private String login_pw; private String worker_name; getset方法略 ```
@Import导入类中的@Autowired无法导入
我现在有一个总的配置类,两个附属配置类 1.总的配置类 ``` @Configuration @EnableWebSecurity(debug = true) @EnableJWT //自定义注解 public class AllConfigure ``` 2.附属配置类1 ``` public class JWTConfig ``` 3.附属配置类2 ``` public class SecurityConfig ``` 4.JWT自定义注解 ``` @Retention(RetentionPolicy.RUNTIME) @Target(ElementType.TYPE) @Import(JWTConfig.class) public @interface EnableJwt ``` 5.Security注解 ``` @Retention(RetentionPolicy.RUNTIME) @Target(ElementType.TYPE) @Import(SecurityConfig.class) public @interface EnableSecurity ``` 用JWT注解或者Security注解导入两个配置中的齐总一个会导致@Autowried注入失败,请问各位大神有什么好的解决办法吗
相见恨晚的超实用网站
搞学习 知乎:www.zhihu.com 简答题:http://www.jiandati.com/ 网易公开课:https://open.163.com/ted/ 网易云课堂:https://study.163.com/ 中国大学MOOC:www.icourse163.org 网易云课堂:study.163.com 哔哩哔哩弹幕网:www.bilibili.com 我要自学网:www.51zxw
花了20分钟,给女朋友们写了一个web版群聊程序
参考博客 [1]https://www.byteslounge.com/tutorials/java-ee-html5-websocket-example
爬虫福利二 之 妹子图网MM批量下载
爬虫福利一:27报网MM批量下载    点击 看了本文,相信大家对爬虫一定会产生强烈的兴趣,激励自己去学习爬虫,在这里提前祝:大家学有所成! 目标网站:妹子图网 环境:Python3.x 相关第三方模块:requests、beautifulsoup4 Re:各位在测试时只需要将代码里的变量 path 指定为你当前系统要保存的路径,使用 python xxx.py 或IDE运行即可。
字节跳动视频编解码面经
引言 本文主要是记录一下面试字节跳动的经历。 三四月份投了字节跳动的实习(图形图像岗位),然后hr打电话过来问了一下会不会opengl,c++,shador,当时只会一点c++,其他两个都不会,也就直接被拒了。 七月初内推了字节跳动的提前批,因为内推没有具体的岗位,hr又打电话问要不要考虑一下图形图像岗,我说实习投过这个岗位不合适,不会opengl和shador,然后hr就说秋招更看重基础。我当时
Java学习的正确打开方式
在博主认为,对于入门级学习java的最佳学习方法莫过于视频+博客+书籍+总结,前三者博主将淋漓尽致地挥毫于这篇博客文章中,至于总结在于个人,实际上越到后面你会发现学习的最好方式就是阅读参考官方文档其次就是国内的书籍,博客次之,这又是一个层次了,这里暂时不提后面再谈。博主将为各位入门java保驾护航,各位只管冲鸭!!!上天是公平的,只要不辜负时间,时间自然不会辜负你。 何谓学习?博主所理解的学习,它
程序员必须掌握的核心算法有哪些?
由于我之前一直强调数据结构以及算法学习的重要性,所以就有一些读者经常问我,数据结构与算法应该要学习到哪个程度呢?,说实话,这个问题我不知道要怎么回答你,主要取决于你想学习到哪些程度,不过针对这个问题,我稍微总结一下我学过的算法知识点,以及我觉得值得学习的算法。这些算法与数据结构的学习大多数是零散的,并没有一本把他们全部覆盖的书籍。下面是我觉得值得学习的一些算法以及数据结构,当然,我也会整理一些看过
大学四年自学走来,这些私藏的实用工具/学习网站我贡献出来了
大学四年,看课本是不可能一直看课本的了,对于学习,特别是自学,善于搜索网上的一些资源来辅助,还是非常有必要的,下面我就把这几年私藏的各种资源,网站贡献出来给你们。主要有:电子书搜索、实用工具、在线视频学习网站、非视频学习网站、软件下载、面试/求职必备网站。 注意:文中提到的所有资源,文末我都给你整理好了,你们只管拿去,如果觉得不错,转发、分享就是最大的支持了。 一、电子书搜索 对于大部分程序员...
linux系列之常用运维命令整理笔录
本博客记录工作中需要的linux运维命令,大学时候开始接触linux,会一些基本操作,可是都没有整理起来,加上是做开发,不做运维,有些命令忘记了,所以现在整理成博客,当然vi,文件操作等就不介绍了,慢慢积累一些其它拓展的命令,博客不定时更新 顺便拉下票,我在参加csdn博客之星竞选,欢迎投票支持,每个QQ或者微信每天都可以投5票,扫二维码即可,http://m234140.nofollow.ax.
比特币原理详解
一、什么是比特币 比特币是一种电子货币,是一种基于密码学的货币,在2008年11月1日由中本聪发表比特币白皮书,文中提出了一种去中心化的电子记账系统,我们平时的电子现金是银行来记账,因为银行的背后是国家信用。去中心化电子记账系统是参与者共同记账。比特币可以防止主权危机、信用风险。其好处不多做赘述,这一层面介绍的文章很多,本文主要从更深层的技术原理角度进行介绍。 二、问题引入 假设现有4个人...
Python 基础(一):入门必备知识
目录1 标识符2 关键字3 引号4 编码5 输入输出6 缩进7 多行8 注释9 数据类型10 运算符10.1 常用运算符10.2 运算符优先级 1 标识符 标识符是编程时使用的名字,用于给变量、函数、语句块等命名,Python 中标识符由字母、数字、下划线组成,不能以数字开头,区分大小写。 以下划线开头的标识符有特殊含义,单下划线开头的标识符,如:_xxx ,表示不能直接访问的类属性,需通过类提供
这30个CSS选择器,你必须熟记(上)
关注前端达人,与你共同进步CSS的魅力就是让我们前端工程师像设计师一样进行网页的设计,我们能轻而易举的改变颜色、布局、制作出漂亮的影音效果等等,我们只需要改几行代码,不需...
国产开源API网关项目进入Apache孵化器:APISIX
点击蓝色“程序猿DD”关注我回复“资源”获取独家整理的学习资料!近日,又有一个开源项目加入了这个Java开源界大名鼎鼎的Apache基金会,开始进行孵化器。项目名称:AP...
程序员接私活怎样防止做完了不给钱?
首先跟大家说明一点,我们做 IT 类的外包开发,是非标品开发,所以很有可能在开发过程中会有这样那样的需求修改,而这种需求修改很容易造成扯皮,进而影响到费用支付,甚至出现做完了项目收不到钱的情况。 那么,怎么保证自己的薪酬安全呢? 我们在开工前,一定要做好一些证据方面的准备(也就是“讨薪”的理论依据),这其中最重要的就是需求文档和验收标准。一定要让需求方提供这两个文档资料作为开发的基础。之后开发
网页实现一个简单的音乐播放器(大佬别看。(⊙﹏⊙))
今天闲着无事,就想写点东西。然后听了下歌,就打算写个播放器。 于是乎用h5 audio的加上js简单的播放器完工了。 欢迎 改进 留言。 演示地点跳到演示地点 html代码如下`&lt;!DOCTYPE html&gt; &lt;html&gt; &lt;head&gt; &lt;title&gt;music&lt;/title&gt; &lt;meta charset="utf-8"&gt
Python十大装B语法
Python 是一种代表简单思想的语言,其语法相对简单,很容易上手。不过,如果就此小视 Python 语法的精妙和深邃,那就大错特错了。本文精心筛选了最能展现 Python 语法之精妙的十个知识点,并附上详细的实例代码。如能在实战中融会贯通、灵活使用,必将使代码更为精炼、高效,同时也会极大提升代码B格,使之看上去更老练,读起来更优雅。 1. for - else 什么?不是 if 和 else 才
数据库优化 - SQL优化
前面一篇文章从实例的角度进行数据库优化,通过配置一些参数让数据库性能达到最优。但是一些“不好”的SQL也会导致数据库查询变慢,影响业务流程。本文从SQL角度进行数据库优化,提升SQL运行效率。 判断问题SQL 判断SQL是否有问题时可以通过两个表象进行判断: 系统级别表象 CPU消耗严重 IO等待严重 页面响应时间过长
2019年11月中国大陆编程语言排行榜
2019年11月2日,我统计了某招聘网站,获得有效程序员招聘数据9万条。针对招聘信息,提取编程语言关键字,并统计如下: 编程语言比例 rank pl_ percentage 1 java 33.62% 2 c/c++ 16.42% 3 c_sharp 12.82% 4 javascript 12.31% 5 python 7.93% 6 go 7.25% 7
通俗易懂地给女朋友讲:线程池的内部原理
餐厅的约会 餐盘在灯光的照耀下格外晶莹洁白,女朋友拿起红酒杯轻轻地抿了一小口,对我说:“经常听你说线程池,到底线程池到底是个什么原理?”我楞了一下,心里想女朋友今天是怎么了,怎么突然问出这么专业的问题,但做为一个专业人士在女朋友面前也不能露怯啊,想了一下便说:“我先给你讲讲我前同事老王的故事吧!” 大龄程序员老王 老王是一个已经北漂十多年的程序员,岁数大了,加班加不动了,升迁也无望,于是拿着手里
经典算法(5)杨辉三角
杨辉三角 是经典算法,这篇博客对它的算法思想进行了讲解,并有完整的代码实现。
编写Spring MVC控制器的14个技巧
本期目录 1.使用@Controller构造型 2.实现控制器接口 3.扩展AbstractController类 4.为处理程序方法指定URL映射 5.为处理程序方法指定HTTP请求方法 6.将请求参数映射到处理程序方法 7.返回模型和视图 8.将对象放入模型 9.处理程序方法中的重定向 10.处理表格提交和表格验证 11.处理文件上传 12.在控制器中自动装配业务类 ...
腾讯算法面试题:64匹马8个跑道需要多少轮才能选出最快的四匹?
昨天,有网友私信我,说去阿里面试,彻底的被打击到了。问了为什么网上大量使用ThreadLocal的源码都会加上private static?他被难住了,因为他从来都没有考虑过这个问题。无独有偶,今天笔者又发现有网友吐槽了一道腾讯的面试题,我们一起来看看。 腾讯算法面试题:64匹马8个跑道需要多少轮才能选出最快的四匹? 在互联网职场论坛,一名程序员发帖求助到。二面腾讯,其中一个算法题:64匹
面试官:你连RESTful都不知道我怎么敢要你?
面试官:了解RESTful吗? 我:听说过。 面试官:那什么是RESTful? 我:就是用起来很规范,挺好的 面试官:是RESTful挺好的,还是自我感觉挺好的 我:都挺好的。 面试官:… 把门关上。 我:… 要干嘛?先关上再说。 面试官:我说出去把门关上。 我:what ?,夺门而去 文章目录01 前言02 RESTful的来源03 RESTful6大原则1. C-S架构2. 无状态3.统一的接
求小姐姐抠图竟遭白眼?痛定思痛,我决定用 Python 自力更生!
点击蓝色“Python空间”关注我丫加个“星标”,每天一起快乐的学习大家好,我是 Rocky0429,一个刚恰完午饭,正在用刷网页浪费生命的蒟蒻...一堆堆无聊八卦信息的网页内容慢慢使我的双眼模糊,一个哈欠打出了三斤老泪,就在此时我看到了一张图片:是谁!是谁把我女朋友的照片放出来的!awsl!太好看了叭...等等,那个背景上的一堆鬼画符是什么鬼?!真是看不下去!叔叔婶婶能忍,隔壁老王的三姨妈的四表...
为啥国人偏爱Mybatis,而老外喜欢Hibernate/JPA呢?
关于SQL和ORM的争论,永远都不会终止,我也一直在思考这个问题。昨天又跟群里的小伙伴进行了一番讨论,感触还是有一些,于是就有了今天这篇文。 声明:本文不会下关于Mybatis和JPA两个持久层框架哪个更好这样的结论。只是摆事实,讲道理,所以,请各位看官勿喷。 一、事件起因 关于Mybatis和JPA孰优孰劣的问题,争论已经很多年了。一直也没有结论,毕竟每个人的喜好和习惯是大不相同的。我也看
SQL-小白最佳入门sql查询一
不要偷偷的查询我的个人资料,即使你再喜欢我,也不要这样,真的不好;
项目中的if else太多了,该怎么重构?
介绍 最近跟着公司的大佬开发了一款IM系统,类似QQ和微信哈,就是聊天软件。我们有一部分业务逻辑是这样的 if (msgType = "文本") { // dosomething } else if(msgType = "图片") { // doshomething } else if(msgType = "视频") { // doshomething } else { // doshom...
致 Python 初学者
欢迎来到“Python进阶”专栏!来到这里的每一位同学,应该大致上学习了很多 Python 的基础知识,正在努力成长的过程中。在此期间,一定遇到了很多的困惑,对未来的学习方向感到迷茫。我非常理解你们所面临的处境。我从2007年开始接触 python 这门编程语言,从2009年开始单一使用 python 应对所有的开发工作,直至今天。回顾自己的学习过程,也曾经遇到过无数的困难,也曾经迷茫过、困惑过。开办这个专栏,正是为了帮助像我当年一样困惑的 Python 初学者走出困境、快速成长。希望我的经验能真正帮到你
“狗屁不通文章生成器”登顶GitHub热榜,分分钟写出万字形式主义大作
一、垃圾文字生成器介绍 最近在浏览GitHub的时候,发现了这样一个骨骼清奇的雷人项目,而且热度还特别高。 项目中文名:狗屁不通文章生成器 项目英文名:BullshitGenerator 根据作者的介绍,他是偶尔需要一些中文文字用于GUI开发时测试文本渲染,因此开发了这个废话生成器。但由于生成的废话实在是太过富于哲理,所以最近已经被小伙伴们给玩坏了。 他的文风可能是这样的: 你发现,...
程序员:我终于知道post和get的区别
是一个老生常谈的话题,然而随着不断的学习,对于以前的认识有很多误区,所以还是需要不断地总结的,学而时习之,不亦说乎
《程序人生》系列-这个程序员只用了20行代码就拿了冠军
你知道的越多,你不知道的越多 点赞再看,养成习惯GitHub上已经开源https://github.com/JavaFamily,有一线大厂面试点脑图,欢迎Star和完善 前言 这一期不算《吊打面试官》系列的,所有没前言我直接开始。 絮叨 本来应该是没有这期的,看过我上期的小伙伴应该是知道的嘛,双十一比较忙嘛,要值班又要去帮忙拍摄年会的视频素材,还得搞个程序员一天的Vlog,还要写BU...
相关热词 c#选择结构应用基本算法 c# 收到udp包后回包 c#oracle 头文件 c# 序列化对象 自定义 c# tcp 心跳 c# ice连接服务端 c# md5 解密 c# 文字导航控件 c#注册dll文件 c#安装.net
立即提问