Spring拦截器和SpringAop实现

一、拦截器

1、aop是面向切面编程，原理是java的发射技术。

2、分为三类，before、after、arround

3、springMvc为我们提供了一个适配器HandlerInterceptorAdapter，继承它实现我们自己的拦截器

4、HandlerInterceptorAdapter例子：

package com.interceptor;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.handler.HandlerInterceptorAdapter;
public class BookInterceptor extends HandlerInterceptorAdapter {
	private static Logger Logger = LoggerFactory.getLogger(BookInterceptor.class);

	@Override
	public void afterCompletion(HttpServletRequest paramHttpServletRequest,HttpServletResponse paramHttpServletResponse, Object paramObject, Exception paramException)throws Exception {

	}

	@Override
	public void postHandle(HttpServletRequest paramHttpServletRequest, HttpServletResponse paramHttpServletResponse,Object paramObject, ModelAndView paramModelAndView) throws Exception {
		String url = paramHttpServletRequest.getRequestURI();
		Logger.info("postMethod:" + url);
	}

	@Override
	public boolean preHandle(HttpServletRequest paramHttpServletRequest, HttpServletResponse paramHttpServletResponse,Object paramObject) throws Exception {
		String url = paramHttpServletRequest.getRequestURI();
		Logger.info("preMehtod:" + url);
		return true;
	}
}

配置文件写在applicationContext.xml里面

<!--配置拦截器, 多个拦截器,顺序执行 -->
<mvc:interceptors>
	<mvc:interceptor><!-- 匹配的是url路径， 如果不配置或/**,将拦截所有的Controller -->
		<mvc:mapping path="/**" />
		<bean class="com.interceptor.BookInterceptor"></bean>
	</mvc:interceptor><!-- 当设置多个拦截器时，先按顺序调用preHandle方法，然后逆序调用每个拦截器的postHandle和afterCompletion方法 -->
</mvc:interceptors>

二、完整的切点切面

1、@aspect例子（同时定义切面和切点）

package com.interceptor;
import org.aspectj.lang.annotation.After;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.aspectj.lang.annotation.Pointcut;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Component;

@Component
@Aspect
public class BookAspect {

	private static final Logger logger = LoggerFactory.getLogger(BookAspect.class);

	@Pointcut("execution(* *.*List(..))")
	public void bookaspeck() {

	}

	@Before("bookaspeck()")
	public void bookbefore() {
		logger.info("before...");
	}

	@After("bookaspeck()")
	public void bookafter() {
		logger.info("after...");
	}
}

在applicationContext.xml中配置

<aop:aspectj-autoproxy/>

三、只有切面

1、MethodBeforeAdvice,AfterReturningAdvice只写切面，在配置文件里面定义切点

package com.interceptor;
import java.lang.reflect.Method;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.aop.AfterReturningAdvice;
import org.springframework.aop.MethodBeforeAdvice;
public class BookBeforeAdvice implements MethodBeforeAdvice,AfterReturningAdvice {

	private static Logger Logger = LoggerFactory.getLogger(BookBeforeAdvice.class);
	public void before(Method paramMethod, Object[] paramArrayOfObject, Object paramObject) throws Throwable {
		Logger.info("before...");
	}

	public void afterReturning(Object paramObject1, Method paramMethod, Object[] paramArrayOfObject,Object paramObject2) throws Throwable {
		Logger.info("after...");
	}
}

配置文件：

<bean id="bookBefore" class="com.interceptor.BookBeforeAdvice"/>
<bean id="regexpMethodPointcutAdvisor1" class="org.springframework.aop.support.RegexpMethodPointcutAdvisor"> 
	<property name="advice" ref="bookBefore"/> 
	<property name="patterns" value=".*BookList"> 
	</property>
</bean>
<bean  class="org.springframework.aop.framework.autoproxy.DefaultAdvisorAutoProxyCreator"/>

或

<bean id="bookBefore" class="com.interceptor.BookBeforeAdvice"/>
<bean id="regexpMethodPointcutAdvisor1" class="org.springframework.aop.support.RegexpMethodPointcutAdvisor"> 
	<property name="advice" ref="bookBefore"/> 
	<property name="patterns"> 
		<list> 
			<value>com.book.control.TBookController.queryBookList</value> 
		</list> 
	</property>
</bean>
<bean  class="org.springframework.aop.framework.autoproxy.DefaultAdvisorAutoProxyCreator"/>