Spring中使用Interceptor拦截器拦截请求

本文实现一个基于Spring4.0的Interceptor拦截Controller请求的demo。更多的详细介绍在后续完善。

1、实现HandlerInterceptor接口

本例中的BaseInterceptor类HandlerInterceptor，并实现两个自定义的接口用来分发get和post请求处理。子类通过继承BaseInterceptor类然后重载其中关心的方法来拦截处理不同的请求。你也可以直接实现HandlerInterceptor并在对应的方法中直接进行拦截请求处理。

BaseInterceptor.java代码如下：

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

import com.landsem.update.base.interceptors.IGetInterceptor;
import com.landsem.update.base.interceptors.IPostInterceptor;

public abstract class BaseInterceptor implements HandlerInterceptor,
		IGetInterceptor, IPostInterceptor {

	@Override
	public final void afterCompletion(HttpServletRequest arg0,
			HttpServletResponse arg1, Object arg2, Exception arg3)
			throws Exception {
		// do get
		if (arg0.getMethod().equalsIgnoreCase("get")) {
			afterGetHandlerCompletion(arg0,arg1,arg2,arg3);
		}
		// do post
		else if (arg0.getMethod().equalsIgnoreCase("post")) {
			afterPostHandlerCompletion(arg0,arg1,arg2,arg3);
		}
	}

	@Override
	public final void postHandle(HttpServletRequest arg0, HttpServletResponse arg1,
			Object arg2, ModelAndView arg3) throws Exception {
		// do get
		if (arg0.getMethod().equalsIgnoreCase("get")) {
			postGetHandle(arg0,arg1,arg2,arg3);
		}
		// do post
		else if (arg0.getMethod().equalsIgnoreCase("post")) {
			postPostHandle(arg0,arg1,arg2,arg3);
		}
	}

	@Override
	public final boolean preHandle(HttpServletRequest arg0, HttpServletResponse arg1,
			Object arg2) throws Exception {
		// do get
		if (arg0.getMethod().equalsIgnoreCase("get")) {
			return preGetHandle(arg0, arg1, arg2);
		}
		// do post
		else if (arg0.getMethod().equalsIgnoreCase("post")) {
			return prePostHandle(arg0, arg1, arg2);
		}
		// default
		return true;
	}

	@Override
	public void afterGetHandlerCompletion(HttpServletRequest arg0,
			HttpServletResponse arg1, Object arg2, Exception arg3) {
		// TODO Auto-generated method stub
	}

	@Override
	public void postGetHandle(HttpServletRequest arg0,
			HttpServletResponse arg1, Object arg2, ModelAndView arg3)
			throws Exception {
		// TODO Auto-generated method stub
	}

	@Override
	public boolean preGetHandle(HttpServletRequest arg0,
			HttpServletResponse arg1, Object arg2) throws Exception {
		// TODO Auto-generated method stub
		return true;
	}

	@Override
	public void afterPostHandlerCompletion(HttpServletRequest arg0,
			HttpServletResponse arg1, Object arg2, Exception arg3) {
		// TODO Auto-generated method stub
	}

	@Override
	public void postPostHandle(HttpServletRequest arg0,
			HttpServletResponse arg1, Object arg2, ModelAndView arg3)
			throws Exception {
		// TODO Auto-generated method stub
	}

	@Override
	public boolean prePostHandle(HttpServletRequest arg0,
			HttpServletResponse arg1, Object arg2) throws Exception {
		// TODO Auto-generated method stub
		return true;
	}
}

IGetInterceptor.java代码如下：

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.springframework.web.servlet.ModelAndView;

public interface IGetInterceptor {
	public void afterGetHandlerCompletion(HttpServletRequest arg0,
			HttpServletResponse arg1, Object arg2, Exception arg3);

	public void postGetHandle(HttpServletRequest arg0,
			HttpServletResponse arg1, Object arg2, ModelAndView arg3)
			throws Exception;

	public boolean preGetHandle(HttpServletRequest arg0,
			HttpServletResponse arg1, Object arg2) throws Exception;
}

IPostInterceptor.java的代码如下：

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.springframework.web.servlet.ModelAndView;

public interface IPostInterceptor {
	public void afterPostHandlerCompletion(HttpServletRequest arg0,
			HttpServletResponse arg1, Object arg2, Exception arg3);

	public void postPostHandle(HttpServletRequest arg0,
			HttpServletResponse arg1, Object arg2, ModelAndView arg3)
			throws Exception;

	public boolean prePostHandle(HttpServletRequest arg0,
			HttpServletResponse arg1, Object arg2) throws Exception;
}

DemoInterceptor.java是一个实现拦截post请求的类示例：

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.log4j.Logger;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.servlet.ModelAndView;

import com.landsem.update.base.interceptors.impl.BaseInterceptor;
import com.landsem.update.cache.service.ICacheService;

public class DemoInterceptor extends BaseInterceptor {
	protected static Logger logger = Logger.getLogger(Demo .class);

	@Override
	public void afterPostHandlerCompletion(HttpServletRequest arg0,
			HttpServletResponse arg1, Object arg2, Exception arg3) {
		if (logger.isDebugEnabled()) {
			logger.debug("Demo afterCompletion");
		}
	}

	@Override
	public void postPostHandle(HttpServletRequest arg0,
			HttpServletResponse arg1, Object arg2, ModelAndView arg3)
			throws Exception {
		if (logger.isDebugEnabled()) {
			logger.debug("PublishUpdateInterceptor postPostHandle");
		}
	}

	@Override
	public boolean prePostHandle(HttpServletRequest arg0,
			HttpServletResponse arg1, Object arg2) throws Exception {
		if (logger.isDebugEnabled()) {
			logger.debug("PublishUpdateInterceptor prePostHandle");
		}
		return true;
	}
}

2、在XML配置文件中配置拦截器

本例中使用一个独立的文件applicationContext-interceptors.xml用于描述工程中的拦截器，在web.xml中配置解析该配置文件。

applicationContext-interceptors.xml文件内容如下：

<?xml version="1.0" encoding="UTF-8"?>  
<beans xmlns="http://www.springframework.org/schema/beans"  
   	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
   	xmlns:p="http://www.springframework.org/schema/p"
	xmlns:aop="http://www.springframework.org/schema/aop" 
	xmlns:context="http://www.springframework.org/schema/context"
	xmlns:jee="http://www.springframework.org/schema/jee"
	xmlns:tx="http://www.springframework.org/schema/tx"
	xmlns:mvc="http://www.springframework.org/schema/mvc"
    xsi:schemaLocation="  
        http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.0.xsd
		http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
		http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd
		http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee-4.0.xsd
		http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.0.xsd
		http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd">  
		
	<mvc:interceptors>  
	    <!-- 使用bean定义一个Interceptor，直接定义在mvc:interceptors根下面的Interceptor将拦截所有的请求 -->  
	    <!--    <bean class="com.arvinfei.springmvc.DemoInterceptor"/> -->
            <mvc:interceptor>  
               <mvc:mapping path="/manage/test.shtml"/>
<pre name="code" class="html">               <mvc:mapping path="/manage/test2.shtml"/>

  <!-- 定义在mvc:interceptor下面的表示是对特定的请求才进行拦截的 --> <bean class="com.arvinfei.springmvc.DemoInterceptor"/> </mvc:interceptor> </mvc:interceptors> </beans>

上面的配置DemoInterceptor将拦截/manage/test.shtml和/manage/test.shtml的post请求。

web.xml中指定所有以applicationContext-开头的配置文件，主要内容如下：

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" version="3.0">
  <display-name></display-name>
  <context-param>
    <param-name>contextConfigLocation</param-name>
    <param-value>classpath:applicationContext-*.xml</param-value>
  </context-param>
  <servlet>
    <servlet-name>spring</servlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    <init-param>
      <param-name>contextConfigLocation</param-name>
      <param-value>/WEB-INF/classes/spring-servlet.xml</param-value>
    </init-param>
    <load-on-startup>1</load-on-startup>
  </servlet>
  <servlet-mapping>
    <servlet-name>spring</servlet-name>
    <url-pattern>*.shtml</url-pattern>
  </servlet-mapping>
  <welcome-file-list>
    <welcome-file>index.jsp</welcome-file>
  </welcome-file-list>
</web-app>

关于SpringMVC中拦截器的更多较为详细的介绍可以参考如下博客：

http://itindex.net/detail/50153-springmvc-interceptor