Spring和@Autowired在DelegatingFilterProxy上

Question

我正在尝试将一个spring bean注入过滤器,但无法使其工作.

注入的bean总是"空".我成功地在Controllers和HandlerInterceptors中自动装配这个相同的bean,因此它被正确注释.

过滤器类位于其余控制器的相同基础包下.

这是我的web.xml的相关部分

  <filter>
    <filter-name>CheckSession</filter-name>
    <filter-class>org.springframework.web.filter.DelegatingFilterProxy</filter-class>
  </filter>
  <filter-mapping>
    <filter-name>CheckSession</filter-name>
    <url-pattern>/panel/*</url-pattern>
  </filter-mapping>

这是过滤器的代码

@Component 
public class CheckSession extends OncePerRequestFilter implements Filter {

    @Autowired private Usuario usuario;

    @Override
    protected void doFilterInternal(
        HttpServletRequest request,
        HttpServletResponse response, FilterChain chain)
    throws ServletException, IOException {

        //  always null
        System.out.println("autowired " + usuario);
        chain.doFilter(request,  response);
    }
}

过滤器在每个请求时触发.

这些是"Usuario"bean中的注释

@Component
@Scope(value="session", proxyMode=ScopedProxyMode.TARGET_CLASS)
public class Usuario implements java.io.Serializable { ... }

我错过了什么？谢谢!

Answer 1

尝试显式定义CheckSession bean的名称,看看是否有帮助...像这样:

@Component("CheckSession")
public class CheckSession extends OncePerRequestFilter implements Filter {
    @Autowired private Usuario usuario;

    @Override
    protected void doFilterInternal(HttpServletRequest request,
            HttpServletResponse response, FilterChain chain)
            throws ServletException, IOException {

        //  always null
        System.out.println("autowired " + usuario);
        chain.doFilter(request,  response);
    }
}

关键部分是:@Component("CheckSession")

使事情更漂亮,更容易对付的道路,我会驼峰的名字并重新命名为"checkSession"无处不在(去大写首字母).

Answer 2

适用于Spring 3.2.6:

第一:为您的组件命名,2个选项 - 只做一个

选项A: 注释 - 假设启用了组件扫描

@Component("checkSession")
public class CheckSession extends OncePerRequestFilter {

@Autowired 
Usuario usuario;

@Override
protected void doFilterInternal(final HttpServletRequest request, final HttpServletResponse response, final FilterChain chain) throws ServletException, IOException {

    // not null
    System.out.println("autowired " + usuario);
    chain.doFilter(request,  response);
    }
}

选项B: 通过appliationContext.xml连接bean

<bean id="checkSession" class="com.example.filter.CheckSession"></bean>

第二:连接Spring DelegatingFilterProxy

<filter>
  <filter-name>checkSession</filter-name>
  <filter-class>org.springframework.web.filter.DelegatingFilterProxy</filter-class>
</filter>

<filter-mapping>
  <filter-name>checkSession</filter-name>
  <url-pattern>/*</url-pattern>
</filter-mapping>

注意:bean名称被引用为 filter-name