SpringMVC：详述拦截器

packagecom.zzj.interceptor;

importjavax.servlet.http.HttpServletRequest;
importjavax.servlet.http.HttpServletResponse;

importorg.springframework.web.servlet.HandlerInterceptor;
importorg.springframework.web.servlet.ModelAndView;

public class MyInterceptor implementsHandlerInterceptor{

    @Override
    public booleanpreHandle(HttpServletRequest request, HttpServletResponse response, Object handler)
            throwsException {
//该方法在Handler Method之前被调用
//作用：常用于实现权限

System.out.println("preHandle");
        return false;
    }

    @Override
    public voidpostHandle(HttpServletRequest request, HttpServletResponse response, Object handler,
            ModelAndView modelAndView) throwsException {
//该方法在Handler Method之后，渲染视图之前
//常用于对请求域中的属性或视图做出修改

System.out.println("postHandle");
        
    }

    @Override
    public voidafterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex)
            throwsException {
//该方法在渲染视图之后被调用

　　　　　　//作用：常用于释放资源

System.out.println("afterCompletion");
    }
    
}

<mvc:interceptors>
    <bean class="com.zzj.interceptor.MyInterceptor"></bean>
</mvc:interceptors>

<mvc:interceptors>
    <mvc:interceptor>

　　　　　　<!--

mvc:exclude-mapping用于设置不拦截哪些路径的请求；mvc:mapping用于设置拦截哪些路径的请求，如下例子：

/userinfo只拦截/userinfo请求，不拦截/userinfo/toView.do请求

/userinfo/*拦截/userinfo/xxx请求

-->

        <mvc:mapping path="/userinfo/*"/>
        <bean class="com.zzj.interceptor.MyInterceptor"></bean>
    </mvc:interceptor>
</mvc:interceptors>