学步园

访问目标方法 最简单的做法就是定义增强处理方法时将第一个参数定义为JoinPoint
类型，当该增强处理方法被调用时，该JoinPoint参数就代表了织入增强处理的连接点。JoinPoint里包含了如下几个常用的方法：

Person.java :

public interface Person {
	public String sayHello(String name);
	public void eat(String food);
}

Chinese.java :

@Component
public class Chinese implements Person {

	@Override
	public String sayHello(String name) {
		System.out.println("sayHello方法被调用...");
		return name+" Hello,Spring AOP";
	}

	@Override
	public void eat(String food) {
		System.out.println("我正在吃:"+food);
	}

	
}

FourAdviceTest.java :

@Aspect
public class FourAdviceTest {

	@Around("execution(* com.bean.*.*(..))")
	public Object processTx(ProceedingJoinPoint jp) throws Throwable{
		System.out.println("Around增强:执行目标方法之前，模拟开始事务...");
		Object[] args=jp.getArgs();
		if(args!=null && args.length>0 && args[0].getClass()==String.class){
			args[0]="被改变的参数";
		}
		Object rvt=jp.proceed(args);
		System.out.println("Around增强:执行目标方法之后，模拟结束事务...");
		return rvt+" 新增的内容";
	}
	
	@Before("execution(* com.bean.*.*(..))")
	public void authority(JoinPoint jp){
		System.out.println("Before增强:模拟执行权限检查...");
		System.out.println("Before增强:被织入增强处理的目标方法为："+
				jp.getSignature().getName());
		System.out.println("Before增强：目标方法的参数为："+Arrays.toString(jp.getArgs()));
		System.out.println("Before增强:被织入增强处理的目标对象为："+jp.getTarget());
	}
	
	@AfterReturning(returning="rvt",pointcut="execution(* com.bean.*.*(..))")
	public void log(JoinPoint jp,Object rvt){
		System.out.println("AfterReturning增强：获取目标方法返回值："+rvt);
		System.out.println("AfterReturning增强：模拟记录日志功能...");
		System.out.println("AfterReturning增强：被织入增强处理的目标方法为:"+
				jp.getSignature().getName());
		System.out.println("AfterReturning增强：目标方法的参数为："+
				Arrays.toString(jp.getArgs()));
		System.out.println("AfterReturning增强:被织入增强处理的目标对象为："+
				jp.getTarget());
	}
	
	@After("execution(* com.bean.*.*(..))")
	public void release(JoinPoint jp){
		System.out.println("After增强：模拟方法结束后的释放资源...");
		System.out.println("After增强：被织入增强处理的目标方法为："+
				jp.getSignature().getName());
		System.out.println("After增强：目标方法的参数为："+
				Arrays.toString(jp.getArgs()));
		System.out.println("After增强: 被织入增强处理的目标对象为："+
				jp.getTarget());
	}
}

bean.xml :

<?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:context="http://www.springframework.org/schema/context"
        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-2.5.xsd


http://www.springframework.org/schema/context


http://www.springframework.org/schema/context/spring-context-2.5.xsd


http://www.springframework.org/schema/tx


http://www.springframework.org/schema/tx/spring-tx-2.5.xsd


http://www.springframework.org/schema/aop

                http://www.springframework.org/schema/aop/spring-aop-2.5.xsd">
    
    
    <context:component-scan base-package="com.bean">
        <context:include-filter type="annotation" 
                 expression="org.aspectj.lang.annotation.Aspect"/>
    </context:component-scan>
    
    <aop:aspectj-autoproxy/>
    
 </beans>

Test.java :

public class Test {
	public static void main(String[] args) {
		
		ApplicationContext ctx=new ClassPathXmlApplicationContext("bean.xml");
		Person p=(Person) ctx.getBean("chinese");
		System.out.println(p.sayHello("张三"));
		p.eat("西瓜");
	}
}

运行程序，控制台输出：