AOP的實現

[color=blue]AOP術語:
* Cross cutting concern
* Aspect
* Advice
* Pointcut
* Joinpoint
* Weave
* Target Object
* Proxy
* Introduction[/color]

AOP實例：

[color=red]定義切面：[/color]

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

/**
 * 定義Aspect
 * @author Administrator
 *
 */
@Aspect
public class SecurityHandler {

	/**
	 * 定義Pointcut,Pointcut的名稱就是allAddMethod，此方法不能有返回值和參數，該方法只是一個
	 * 標識
	 * 
	 * Pointcut的內容是一個表達式，描述那些對象的那些方法（訂閱Joinpoint）
	 */
	@Pointcut("execution(* add*(..)) || execution(* del*(..))")
	private void allAddMethod(){};

	/**
	 * 定義Advice，標識在那個切入點何處織入此方法
	 */
	@Before("allAddMethod()")
	private void checkSecurity() {
		System.out.println("----------checkSecurity()---------------");
	}

}

[color=red]用戶接口：[/color]

public interface UserManager {

	public void addUser(String username, String password);

	public void deleteUser(int id);

	public void modifyUser(int id, String username, String password);

	public String findUserById(int id);
}

[color=red]用戶實現：[/color]

public class UserManagerImpl implements UserManager {

	public void addUser(String username, String password) {
		System.out.println("-------UserManagerImpl.addUser()----------");
	}

	public void deleteUser(int id) {
		System.out.println("-------UserManagerImpl.deleteUser()----------");
	}

	public String findUserById(int id) {
		System.out.println("-------UserManagerImpl.findUserById()----------");
		return null;
	}

	public void modifyUser(int id, String username, String password) {
		System.out.println("-------UserManagerImpl.modifyUser()----------");
	}

//	private void checkSecurity() {
//		System.out.println("----------checkSecurity()---------------");
//	}
}

[color=red]客戶端實現：[/color]

import org.springframework.beans.factory.BeanFactory;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class Client {

	public static void main(String[] args) {
		BeanFactory factory = new ClassPathXmlApplicationContext("applicationContext.xml");

		UserManager userManager = (UserManager)factory.getBean("userManager");

		userManager.addUser("張三", "123");
		userManager.deleteUser(1);
	}
}

[color=red]
applicationContext.xml的配置：[/color]

<?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">
	<aop:aspectj-autoproxy/>
	<bean id="securityHandler" class="com.bjsxt.spring.SecurityHandler"/>           
	<bean id="userManager" class="com.bjsxt.spring.UserManagerImpl"/>
</beans>