SpringMVC的filter怎么使用Autowired依賴注入bean

 

有的時候根據我們業務的需要，我們需要在web項目中定義一個自己的filter,並想在這個filter中使用@Autowired注入bean供我們使用。如果直接使用的話是不行的，需要我們在xml文件中進行配置。下面就根據我的一個項目寫一個示例:

步驟一、定義一個ClientSessionFilter，在這個Filter中注入我們想要的bean

public class ClientSessionFilter implements Filter {
    private static Logger log = Logger.getLogger(ClientSessionFilter.class);
    @Autowired
    private RequestData requestData; //我們想要注入的bean
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
    }
    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        ObjectMapper mapper = new ObjectMapper();
        HttpServletRequest httpServletReq = (HttpServletRequest) request;
        String session = httpServletReq.getHeader("S");
        ClientSession cs;
        if(StringUtils.isNotBlank(session)) {
            try {
                cs = mapper.readValue(session, ClientSession.class);
            } catch (Exception e) {
                log.error("Session序列化錯誤" + e);
                throw new BusinessException(401, "Session序列化錯誤");
            }
            if(log.isDebugEnabled()) {
                log.debug(cs);
            }
            requestData.setClientSession(cs);
        }
        chain.doFilter(request, response);
    }
    @Override
    public void destroy() {
    }
}

 

步驟二、在spring的配置文件application.xml中配置我們想要的bean和自定義的filter

<bean id="requestData" scope="request" class="cn.ucmed.common.cache.RequestData">
    <aop:scoped-proxy/> //這個標簽可以參考上一遍博客
</bean>

<bean id="clientSessionFilter" class="cn.ucmed.baseline.d2d.filter.ClientSessionFilter" />

步驟三、在web.xml中配置fileter

<filter>
  <filter-name>filterProxy</filter-name>
  <filter-class>org.springframework.web.filter.DelegatingFilterProxy</filter-class>
  <async-supported>true</async-supported>
  <init-param>
    <param-name>targetBeanName</param-name>
    <param-value>clientSessionFilter</param-value>
  </init-param>
  <init-param>
    <param-name>targetFilterLifecycle</param-name>
    <param-value>true</param-value>
  </init-param>
</filter>
<filter-mapping>
  <filter-name>filterProxy</filter-name>
  <url-pattern>/registeryuyue/*</url-pattern>
</filter-mapping>