tomcat服务器启动，Filter 的构造函数被调用了两次，doFilter函数调用了一次，

Posted 2023-04-05

tomcat服务器启动，Filter 的构造函数被调用了两次，doFilter函数调用了一次，构造函数被调用两次怎么解决

参考技术A No matching bean of type [com.hundsun.maw.manage.log.getlog.TestService] 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)
Could not autowire field: private com.hundsun.maw.manage.log.getlog.TestService com.hundsun.maw.manage.usergeneral.action.UserGeneralAction.testservice; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No matching bean of type [com.hundsun.maw.manage.log.getlog.TestService] 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)
Error creating bean with name 'userGeneralAction': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private com.hundsun.maw.manage.log.getlog.TestService com.hundsun.maw.manage.usergeneral.action.UserGeneralAction.testservice; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No matching bean of type [com.hundsun.maw.manage.log.getlog.TestService] 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)
Unable to instantiate Action, userGeneralAction, defined for 'searchUserGeneral' in namespace '/userGeneralSearch'Error creating bean with name 'userGeneralAction': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private com.hundsun.maw.manage.log.getlog.TestService com.hundsun.maw.manage.usergeneral.action.UserGeneralAction.testservice; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No matching bean of type [com.hundsun.maw.manage.log.getlog.TestService] 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)追问

？？？

Filter的声明周期

1.首先是在服务器在启动的时候，执行Filter的构造函数，然后是init方法。
2.在请求到达的时候调用doFilter方法里的语句。
3.执行chain.doFilter函数：

public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
throws IOException, ServletException {

System.out.println("执行了doFilter");
chain.doFilter(request, response);
System.out.println("返回了doFilter");

}

 

每一次拦截请求时都会调用。
参数：
ServletRequest request
> 请求报文
ServletResponse response
> 响应报文
FilterChain chain
> 该对象的作用就是放行请求：
可以通过 chain.doFilter(request,response) 放行请求。
当调用chain.doFilter()就相当于调用目标资源的service（）方法。
4.服务器运行请求的web资源。
4.再之后是doFilter的剩下的语句。
5.最后是destroy方法