手头上有对所有请求做权限认证的需求，必须要在执行rest方法之前判断用户是否是登录状态，也就是要判断session存不存在，这里使用ContainerRequestFilter，从名字上也能看出来它是一个过滤器，会将所有请求拦截下来，之后做什么处理就随我们拉。

    首先是web.xml配置：

<servlet>  <servlet-name>Jersey REST Service</servlet-name>  <servlet-class>  com.sun.jersey.spi.container.servlet.ServletContainer  </servlet-class>  <init-param>  <param-name>com.sun.jersey.spi.container.ContainerRequestFilters</param-name>  <!-- 如果想加入多个拦截器，请用;隔开 -->  <param-value>com.my.webservice.TestRequestFilter</param-value>  </init-param>  <load-on-startup>1</load-on-startup>  
</servlet>  
<servlet-mapping>  <servlet-name>Jersey REST Service</servlet-name>  <url-pattern>/*</url-pattern>  
</servlet-mapping>  

下面是具体代码：

public class TestRequestFilter implements ContainerRequestFilter{@Context private HttpServletRequest servletRequest;@Contextprivate HttpServletResponse servletResponse;@Overridepublic ContainerRequest filter(ContainerRequest creq) {System.out.println("TestRequestFilter Request:" + creq);if(!servletRequest.getRequestURL().toString().endsWith("/login") && !servletRequest.getMethod().equals("OPTIONS")){Response response = Response.ok(new ErrorJSON(99, "error")).status(401).type(MediaType.APPLICATION_JSON).build();throw new WebApplicationException(response); // Throw new UnAuthorized }return creq;}}