AOP之基于@Aspect 注解与Schema(xml)区别

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基于@Aspect 注解

基于@Aspect 注解的AOP开发主要需要目标类、切面、配置文件。
调用关系如图：
这里写图片描述

首先引入jar包：
下载jar
目标类（HelloWorld）：

package com.demo.spring.aop;public class Helloworld {    protected String message;//定义String 类型变量    public String getMessage() {        return message;    }    public void setMessage(String message) {        this.message = message;    }    public void execute(){        System.out.println("Hello"+getMessage()+"!");    }}

切面：

package com.demo.spring.aop;import org.aspectj.lang.JoinPoint;import org.aspectj.lang.ProceedingJoinPoint;import org.aspectj.lang.annotation.After;import org.aspectj.lang.annotation.Around;import org.aspectj.lang.annotation.Aspect;import org.aspectj.lang.annotation.Before;import org.aspectj.lang.annotation.Pointcut;@Aspectpublic class MyAspect {    /**     * 定义切入点函数     */    @Pointcut("execution(* com.demo.spring.aop.*.execute*(..))")    void pointcut(){    }    /**     * 使用@Before声明前置通知     * @param thisJoinPoint     */    @Before("pointcut()")    public void beforeExecute(JoinPoint thisJoinPoint){        System.out.println("start to say:");    }    /**     * 使用@Around 注解声明环绕通知     * @param thisJoinPoint     * @return     * @throws Throwable     */    @Around("pointcut()")    public Object userOperate(ProceedingJoinPoint thisJoinPoint) throws Throwable{        System.out.println("before 之前");        Object va=thisJoinPoint.proceed();        System.out.println("after 之前");        return va;    }    /**     * 使用@After 注解声明后置通知     * @param thisJoinPoint     */    @After("pointcut()")    public void afterExecute(JoinPoint thisJoinPoint){        System.out.print("end!");    }}

applicationContext.xml配置文件：

<?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:aop="http://www.springframework.org/schema/aop"    xmlns:tx="http://www.springframework.org/schema/tx"    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.0.xsd           http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.0.xsd           http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.0.xsd">    <bean id="Helloworld" class="com.demo.spring.aop.Helloworld">        <property name="message">            <value>World</value>            </property>    </bean>    <aop:aspectj-autoproxy></aop:aspectj-autoproxy>    <bean id="myAspect" class="com.demo.spring.aop.MyAspect"></bean></beans>

客户端调用：
package com.demo.spring.aop;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.FileSystemXmlApplicationContext;

public class Test {

public static void main(String[] args) {    ApplicationContext ctx=new FileSystemXmlApplicationContext("WebRoot/WEB-INF/applicationContext.xml");    Helloworld hello=(Helloworld) ctx.getBean("Helloworld");    hello.execute();}

}
这中方式主要是用Spring的注解方式开发AOP，还有一种是通过Schema(xml)的方式

基于Schema(xml)

与@Aspect注解相比不同之处主要在切面类与配置文件上，切面类不再用注解，而是在配置文件中配置增强
切面类：

package com.demo.spring.aop;import org.aspectj.lang.JoinPoint;import org.aspectj.lang.ProceedingJoinPoint;import org.aspectj.lang.annotation.Aspect;/** * 切面类 * @author dandan * */@Aspectpublic class MyAspect {    /**     * 前置通知     * @param thisJoinPoint     */    public void beforeExecute(JoinPoint thisJoinPoint){        System.out.println("start to say：");    }    /**     * 环绕通知类     * @param thisJoinPoint     * @return     * @throws Throwable     */    public Object userOperate(ProceedingJoinPoint thisJoinPoint) throws Throwable{        return thisJoinPoint.proceed();    }    /**     * 后置通知类     * @param thisJoinPoint     */    public void  afterExecute(JoinPoint thisJoinPoint){        System.out.println("end!");    }}

配置文件：

<?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:aop="http://www.springframework.org/schema/aop"    xmlns:tx="http://www.springframework.org/schema/tx"    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.0.xsd           http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.0.xsd           http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.0.xsd">    <bean id="HelloWorld" class="com.demo.spring.aop.HelloWorld">        <property name="message">            <value>World</value>        </property>    </bean>    <bean id="myAspect" class="com.demo.spring.aop.MyAspect"></bean>    <aop:config>        <!-- 定义切面 -->        <aop:aspect id="aopAspect" ref="myAspect">            <!-- 定义切点 -->            <aop:pointcut id="pointcut"                     expression="execution(* execute(..)) and target(com.demo.spring.aop.HelloWorld)"/>            <!-- 定义通知 -->            <aop:before pointcut-ref="pointcut" method="beforeExecute"/>            <aop:around pointcut-ref="pointcut" method="userOperate"/>            <aop:after  pointcut-ref="pointcut" method="afterExecute"/>        </aop:aspect>    </aop:config></beans>

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