spring AOP (使用AspectJ的xml方式 的aop实现) (7)

目录

• 一、定义计算器接口跟实现类
• 二、定义两个切面，日志切面和验证切面
• 三、在xml中配置切面
• 四、测试类

一、定义计算器接口跟实现类

public interface ArithmeticCalculator {
    int add(int i, int j);
    int sub(int i, int j);
    
    int mul(int i, int j);
    int div(int i, int j);
}

public class ArithmeticCalculatorImpl implements ArithmeticCalculator {
    @Override
    public int add(int i, int j) {
        int result = i + j;
        return result;
    }
    @Override
    public int sub(int i, int j) {
        int result = i - j;
        return result;
    }
    @Override
    public int mul(int i, int j) {
        int result = i * j;
        return result;
    }
    @Override
    public int div(int i, int j) {
        int result = i / j;
        return result;
    }
}  

二、定义两个切面，日志切面和验证切面

• 日志:

package com.hp.spring.aop.xml;
import java.util.Arrays;
import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.ProceedingJoinPoint;
public class LoggingAspect {
    
    public void beforeMethod(JoinPoint joinPoint){
        String methodName = joinPoint.getSignature().getName();
        Object [] args = joinPoint.getArgs();
        
        System.out.println("The method " + methodName + " begins with " + Arrays.asList(args));
    }
    
    public void afterMethod(JoinPoint joinPoint){
        String methodName = joinPoint.getSignature().getName();
        System.out.println("The method " + methodName + " ends");
    }
    
    public void afterReturning(JoinPoint joinPoint, Object result){
        String methodName = joinPoint.getSignature().getName();
        System.out.println("The method " + methodName + " ends with " + result);
    }
    
    public void afterThrowing(JoinPoint joinPoint, Exception e){
        String methodName = joinPoint.getSignature().getName();
        System.out.println("The method " + methodName + " occurs excetion:" + e);
    }
    
    public Object aroundMethod(ProceedingJoinPoint pjd){
        
        Object result = null;
        String methodName = pjd.getSignature().getName();
        
        try {
            //前置通知
            System.out.println("The method " + methodName + " begins with " + Arrays.asList(pjd.getArgs()));
            //执行目标方法
            result = pjd.proceed();
            //返回通知
            System.out.println("The method " + methodName + " ends with " + result);
        } catch (Throwable e) {
            //异常通知
            System.out.println("The method " + methodName + " occurs exception:" + e);
            throw new RuntimeException(e);
        }
        //后置通知
        System.out.println("The method " + methodName + " ends");
        
        return result;
    }
}

• 验证:

package com.hp.spring.aop.xml;
import java.util.Arrays;
import org.aspectj.lang.JoinPoint;
public class VlidationAspect {
    public void validateArgs(JoinPoint joinPoint){
        System.out.println("-->validate:" + Arrays.asList(joinPoint.getArgs()));
    }
    
}

三、在xml中配置切面

<?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"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.0.xsd">
    <!-- 配置 bean -->
    <bean id="arithmeticCalculator" 
        class="com.hp.spring.aop.xml.ArithmeticCalculatorImpl"></bean>
    <!-- 配置切面的 bean. -->
    <bean id="loggingAspect"
        class="com.hp.spring.aop.xml.LoggingAspect"></bean>
    <bean id="vlidationAspect"
        class="com.hp.spring.aop.xml.VlidationAspect"></bean>
    <!-- 配置 AOP -->
    <aop:config>
        <!-- 配置切点表达式 -->
        <aop:pointcut expression="execution(* com.hp.spring.aop.xml.ArithmeticCalculator.*(..))" 
            id="pointcut"/>
        <!-- 配置切面及通知 -->
        <aop:aspect ref="loggingAspect" order="2">
            <aop:before method="beforeMethod" pointcut-ref="pointcut"/>
            <aop:after method="afterMethod" pointcut-ref="pointcut"/>
            <aop:after-throwing method="afterThrowing" pointcut-ref="pointcut" throwing="e"/>
            <aop:after-returning method="afterReturning" pointcut-ref="pointcut" returning="result"/>
            <!--  
            <aop:around method="aroundMethod" pointcut-ref="pointcut"/>
            -->
        </aop:aspect>    
        <aop:aspect ref="vlidationAspect" order="1">
            <aop:before method="validateArgs" pointcut-ref="pointcut"/>
        </aop:aspect>
    </aop:config>
</beans>

四、测试类

package com.hp.spring.aop.xml;

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

public class Main {
	
	public static void main(String[] args) {
		
		ApplicationContext ctx = new ClassPathXmlApplicationContext("beans-aspectj-xml.xml");
		ArithmeticCalculator arithmeticCalculator = (ArithmeticCalculator) ctx.getBean("arithmeticCalculator");
		
		System.out.println(arithmeticCalculator.getClass().getName());
		
		int result = arithmeticCalculator.add(1, 2);
		System.out.println("result:" + result);
		
		result = arithmeticCalculator.div(1000, 0);//这里故意除以0 让程序出错，让切面得到异常通知
		System.out.println("result:" + result);
	}
	
}

打印出：
com.sun.proxy.$Proxy2
-->validate:[1, 2]
The method add begins with [1, 2]
The method add ends
The method add ends with 3
result:3
-->validate:[1000, 0]
The method div begins with [1000, 0]
The method div ends
The method div occurs excetion:java.lang.ArithmeticException: / by zero
Exception in thread "main" java.lang.ArithmeticException: / by zero
at com.hp.spring.aop.xml.ArithmeticCalculatorImpl.div(ArithmeticCalculatorImpl.java:25)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
...

整个系列项目代码： http://git.oschina.net/nmc5/spring