已解决org.springframework.beans.factory.UnsatisfiedDependencyException org.springframework.beans.factor

迷南。 2023-09-26 19:04 82阅读 0赞

已解决org.springframework.beans.factory.UnsatisfiedDependencyException org.springframework.beans.factory.异常的正确解决方法，亲测有效！！！

![在这里插入图片描述][a98eec5618e9416f8adf82755122428f.webp_pic_center]

#### 文章目录 ####

*   *  报错问题
     *  解决方法
     *  声明

### 报错问题 ###

粉丝群里面的一个小伙伴敲代码时发生了报错（当时他心里瞬间凉了一大截，跑来找我求助，然后顺利帮助他解决了，顺便记录一下希望可以帮助到更多遇到这个bug不会解决的小伙伴），报错信息如下：

![在这里插入图片描述][8f076594400b491986ca13af92b59b0c.jpeg_pic_center]  
org.springframework.beans.factory.UnsatisfiedDependencyException org.springframework.beans.factory.BeanNotOfRequiredTypeException 异常  
在进行ssm框架整合的时候，在进行相关的测试代码以及配置文件写完以后，tomcat服务器启动以后，就报了这个异常  
org.springframework.beans.factory.BeanNotOfRequiredTypeException，  
这个是springAOP基于注解的配置时，发生了动态代理的异常，找不到指定的动态代理，属于代理注入的异常。

org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'userController': Unsatisfied dependency expressed through field 'userService'; nested exception is org.springframework.beans.factory.BeanNotOfRequiredTypeException: Bean named 'userServiceImpl' is expected to be of type 'cn.demo.service.impl.UserServiceImpl' but was actually of type 'com.sun.proxy.$Proxy20'
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:587)
    at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:91)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:373)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1348)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:578)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:501)
    at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:317)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:228)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:315)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:760)
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:869)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:550)
    at org.springframework.web.servlet.FrameworkServlet.configureAndRefreshWebApplicationContext(FrameworkServlet.java:672)
    at org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:638)
    at org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:686)
    at org.springframework.web.servlet.FrameworkServlet.initWebApplicationContext(FrameworkServlet.java:554)
    at org.springframework.web.servlet.FrameworkServlet.initServletBean(FrameworkServlet.java:499)
    at org.springframework.web.servlet.HttpServletBean.init(HttpServletBean.java:172)
    at javax.servlet.GenericServlet.init(GenericServlet.java:158)
    at org.apache.catalina.core.StandardWrapper.initServlet(StandardWrapper.java:1144)
    at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1091)
    at org.apache.catalina.core.StandardWrapper.allocate(StandardWrapper.java:773)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:133)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:496)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:81)
    at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:650)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342)
    at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:803)
    at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
    at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:790)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1468)
    at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    at java.lang.Thread.run(Thread.java:745)
    Caused by: org.springframework.beans.factory.BeanNotOfRequiredTypeException: Bean named 'userServiceImpl' is expected to be of type 'cn.demo.service.impl.UserServiceImpl' but was actually of type 'com.sun.proxy.$Proxy20'
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.checkBeanNotOfRequiredType(DefaultListableBeanFactory.java:1527)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.checkBeanNotOfRequiredType(DefaultListableBeanFactory.java:1534)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.raiseNoMatchingBeanFound(DefaultListableBeanFactory.java:1505)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1104)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1065)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:584)
    ... 39 more

### 解决方法 ###

解决方法如下

![在这里插入图片描述][51977e86019c4440b7d8465001aeac05.png]  
观察错误的日志，特别是关注于Caused by里面的内容，

Caused by: org.springframework.beans.factory.BeanNotOfRequiredTypeException: Bean named ‘userServiceImpl’ is expected to be of type ‘cn.demo.service.impl.UserServiceImpl’ but was actually of type ‘com.sun.proxy.$Proxy20’  
由这个可以知道，spring的AOP注解配置时动态代理的异常，实现类UserServiceImpl不能使用jdk的动态代理注入，jdk的动态代理不支持类的注入，只支持接口的注入。如果不想使用jdk的接口动态代理，想要使用类的代理，那么就使用cglib的代理，需要引用cglib的依赖。  
所以，在知道原因之后，我们就可以这样做，  
在spring的配置文件applicationContext.xml中，添加aop:aspectj-autoproxy，加上属性  
proxy-target-class = “true”，也就是<aop:aspectj-autoproxy proxy-target-class = “true”> </aop:aspectj-autoproxy>，这样就是使用了类的动态代理。  
解释说明：proxy-target-class的属性值决定是基于接口的动态代理还是基于类的代理被创建  
proxy-target-class = true 当它的属性值设置为true的时候，是使用基于类的动态代理，需要引入cglib的依赖。  
proxy-target-class = false 当它的属性值设置为false或者是不设置为默认值的时候，是使用jdk的接口的动态代理，标准的jdk的动态代理将会起作用。

### 声明 ###

解决方法也是我在网上找的，如有侵权联系我删除

[a98eec5618e9416f8adf82755122428f.webp_pic_center]: https://img-blog.csdnimg.cn/a98eec5618e9416f8adf82755122428f.webp#pic_center
[8f076594400b491986ca13af92b59b0c.jpeg_pic_center]: https://img-blog.csdnimg.cn/8f076594400b491986ca13af92b59b0c.jpeg#pic_center
[51977e86019c4440b7d8465001aeac05.png]: https://img-blog.csdnimg.cn/51977e86019c4440b7d8465001aeac05.png