spring3: 切面及通知实例 Aspectj的aop

1.前置通知

接口：

package chapter1.server;

public interface IHelloService {

	public void sayAdvisorBefore(String param) ;
}

　　实现

package chapter1.service.impl;

import chapter1.server.IHelloService;

public class HelloService implements IHelloService {	

	public void sayAdvisorBefore(String param) {
		// TODO Auto-generated method stub
		 System.out.println("============say " + param);
	}

}

　　配置：

<!-- 启动对Aspectj的支持 -->
<aop:aspectj-autoproxy/>
<bean id="helloService" class="chapter1.service.impl.HelloService" />
<bean id="aspect" class="chapter1.aop.HelloAspect"/>

　　aop：

package chapter1.aop;

import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.aspectj.lang.annotation.Pointcut;

@Aspect
public class HelloAspect {

	//定义切入点
	@Pointcut(value="execution(* chapter1..*.sayAdvisorBefore(java.lang.String)) && args(param)", argNames = "param")
    public void beforePointcut(String param) {}

	//定义通知
    @Before(value = "beforePointcut(param)", argNames = "param")
    public void beforeAdvice(String param) {
        System.out.println("===========before advice param:" + param);
    }
}

　　测试程序：

//前置通知
	public void testAspectj()
	{
		ApplicationContext context = new ClassPathXmlApplicationContext("chapter1/aspectj.xml");
		IHelloService hello = context.getBean("helloService", IHelloService.class);
		hello.sayAdvisorBefore("before");
	}

　　

2.后置返回通知

接口

package chapter1.server;

public interface IHelloService2 {
	public int sayAfterReturning(String param);
}

　　实现

package chapter1.service.impl;

import chapter1.server.IHelloService2;

public class HelloService2 implements IHelloService2 {

	public int sayAfterReturning(String param) {
		// TODO Auto-generated method stub
		System.out.println("============ say after returning:" + param);
		return 1;
	}

}

　　配置:

<aop:aspectj-autoproxy/>
<bean id="helloService" class="chapter1.service.impl.HelloService2" />
<bean id="aspect" class="chapter1.aop.HelloAspect2"/>

　　aop:

package chapter1.aop;

import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Pointcut;
import org.aspectj.lang.annotation.AfterReturning;

@Aspect
public class HelloAspect2 {

	//方法一
	//通知
	@AfterReturning(
			//value="execution(* chapter1..*.sayAdvisorBefore(java.lang.String)) and args(param)",
			value="execution(* chapter1..*.sayAfterReturning(..))",
			argNames="retVal",
			returning="retVal")
	public void afterReturningAdvice(Object retVal)
	{
		System.out.println("================= return after advice : " + retVal);
	}

	//方法二
	//定义切入点
	@Pointcut(value="execution(* chapter1..*.sayAfterReturning(java.lang.String) and args(param))", argNames="param")
	public void returnPointcut(String param) {}

	public void afterReturningAdvice2(Object retVal)
	{

	}

}

　　测试程序：

//后置返回通知
	public void testAspectAfterReturning()
	{
		ApplicationContext context = new ClassPathXmlApplicationContext("chapter1/aspectj2.xml");
		IHelloService2 hello = context.getBean("helloService", IHelloService2.class);
		hello.sayAfterReturning("hahah");
	}

　　

3.后置错误通知

接口

package chapter1.server;

public interface IHelloService3 {
	public boolean sayAfterThrow(String param);
}

　　实现：

package chapter1.service.impl;

import chapter1.server.IHelloService3;

public class HelloService3 implements IHelloService3 {

	public boolean sayAfterThrow(String param) {
		// TODO Auto-generated method stub
		System.out.println("=========say after throw:" + param);
		throw new RuntimeException();
	}

}

　　配置：

<!-- 开启对Aspectj的支持 -->
<aop:aspectj-autoproxy />
<bean id="helloService" class="chapter1.service.impl.HelloService3" />
<bean id="aspect" class="chapter1.aop.HelloAspect3" />

　　aop:

package chapter1.aop;

import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.AfterThrowing;

@Aspect
public class HelloAspect3 {

	@AfterThrowing(value="execution(* chapter1..*.sayAfterThrow(java.lang.String))", argNames="exception", throwing="exception")
	public void afterThrowAdvice(Exception exception)
	{
		System.out.println("=========after throwing advice : " + exception);
	}
}

　　测试程序：

//后置错误通知
	public void testAfterThrow()
	{
		ApplicationContext context = new ClassPathXmlApplicationContext("chapter1/aspectj3.xml");
		IHelloService3 hello = context.getBean("helloService", IHelloService3.class);
		hello.sayAfterThrow("error");
	}

　　

4.环绕通知

接口：

package chapter1.server;

public interface IHelloService4 {
	public void sayAround(String param);
}

　　实现：

package chapter1.service.impl;

import chapter1.server.IHelloService4;

public class HelloService4 implements IHelloService4 {

	public void sayAround(String param) {
		// TODO Auto-generated method stub
		System.out.println("============= say around: " + param);
	}

}

　　配置：

<!-- 开启对Aspectj的支持 -->
<aop:aspectj-autoproxy/>
<bean id="helloService" class="chapter1.service.impl.HelloService4" />
<bean id="aspect" class="chapter1.aop.HelloAspect4"/>

　　aop:

package chapter1.aop;

import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Around;

@Aspect
public class HelloAspect4 {

	@Around(value="execution(* chapter1..*.sayAround(java.lang.String))", argNames="param")
	public Object aroundAdvice(ProceedingJoinPoint pjp) throws Throwable
	{
		System.out.println("========= around before advice");
		Object retVal = pjp.proceed(new Object[] {"我被替换了呀"});
		System.out.println("========= around before advice");
		return retVal;

	}
}

　　测试程序：

//环绕通知
	public void testAround()
	{
		ApplicationContext context = new ClassPathXmlApplicationContext("chapter1/aspectj4.xml");
		IHelloService4 hello = context.getBean("helloService", IHelloService4.class);
		hello.sayAround("gaga ya xia ba");
	}

　　

5.引入（结合chatper1.service.IHelloService程序来试验）

接口：

package chapter1.server;

public interface IHelloService5 {
	public void sayDeclare();
}

　　实现：

package chapter1.service.impl;

import chapter1.server.IHelloService5;

public class HelloService5 implements IHelloService5 {

	public void sayDeclare() {
		// TODO Auto-generated method stub
		System.out.println("=========== say declare  " );
	}

}

　　配置：

<!-- 开启对Aspect的支持 -->
<aop:aspectj-autoproxy/>
<bean id="helloService" class="chapter1.service.impl.HelloService"/>
<bean id="aspect" class="chapter1.aop.HelloAspect5"/>

　　aop:

package chapter1.aop;

import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.DeclareParents;

import chapter1.server.IHelloService5;
import chapter1.service.impl.HelloService5;

@Aspect
public class HelloAspect5 {

	@DeclareParents(
			value="chapter1..*.HelloService+",
			defaultImpl=HelloService5.class)
	public IHelloService5 ihelloService5;

}

　　测试程序：

//引入
	@Test
	public void testDeclare()
	{
		ApplicationContext context = new ClassPathXmlApplicationContext("chapter1/aspectj5.xml");
		IHelloService5 hello = context.getBean("helloService", IHelloService5.class);
		hello.sayDeclare();
	}