[Java] Spring_1500_AOP_Annotation-优快云博客

本文介绍了如何在Spring框架中使用面向切面编程(AOP)，通过具体的代码示例展示了如何定义切面类、配置切入点表达式及前置通知、后置通知等。同时，还展示了如何在业务逻辑中注入切面，实现对方法调用的日志记录。

15, <aop:aspectj-autoproxy />

把逻辑织入到原来那个方法里面去。
@Aspect 说明这是一个切面类

@Component 初始化这个类

package com.bjsxt.aop;

LogInterceptor 很好！很好！写的！

package com.bjsxt.aop;

import org.aspectj.lang.annotation.AfterReturning;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.springframework.stereotype.Component;

@Aspect
@Component
public class LogInterceptor {
		
	@Before("execution(public void com.bjsxt.dao.impl.UserDAOImpl.save(com.bjsxt.model.User))")  // 这就是织入点语法
	public void before() {
		System.out.println("method start");
	}
	@AfterReturning("execution(public * com.bjsxt.dao..*.*(..))")
	public void afterReturning() {
		System.out.println("method after returning");
	}

}
//

package com.bjsxt.aop;

LogInterceptor 2，很好！很好！写的！

package com.bjsxt.aop;

import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.AfterReturning;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.aspectj.lang.annotation.Pointcut;
import org.springframework.stereotype.Component;

@Aspect
@Component
public class LogInterceptor {
	@Pointcut("execution(public * com.bjsxt.service..*.add(..))")
	public void myMethod(){};
	
	@Before("myMethod()")
	public void before() {
		System.out.println("method before");
	}
	
	@Around("myMethod()")
	public void aroundMethod(ProceedingJoinPoint pjp) throws Throwable {
		System.out.println("method around start");
		pjp.proceed();
		System.out.println("method around end");
	}
}
//

package com.bjsxt.dao;

interface UserDAO

package com.bjsxt.dao;

import com.bjsxt.model.User;

public interface UserDAO { // 和数据库打交道
	public void save(User u); // 访问  mysql 的代码
}

package com.bjsxt.dao.impl;

UserDAOImpl

package com.bjsxt.dao.impl;

import org.springframework.stereotype.Component;

import com.bjsxt.dao.UserDAO;
import com.bjsxt.model.User;

@Component("u") 
public class UserDAOImpl implements UserDAO {

	public void save(User user) {
		//Hibernate
		//JDBC
		//XML
		//NetWork
		System.out.println("user saved!");
		//throw new RuntimeException("exeption!");
	}

}

packagecom.bjsxt.model;

User (用户类：具有名字和密码两个属性)

package com.bjsxt.model;

public class User {
	private String username;
	private String password;

	public String getUsername() {
		return username;
	}

	public void setUsername(String username) {
		this.username = username;
	}

	public String getPassword() {
		return password;
	}

	public void setPassword(String password) {
		this.password = password;
	}

}

package com.bjsxt.service;
UserService 用户服务层

package com.bjsxt.service;
import javax.annotation.Resource;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.stereotype.Component;

import com.bjsxt.dao.UserDAO;
import com.bjsxt.model.User;


@Component("userService")
public class UserService {
	
	private UserDAO userDAO;  
	
	public void init() {
		System.out.println("init");
	}
	
	public void add(User user) {
		userDAO.save(user);
	}
	public UserDAO getUserDAO() {
		return userDAO;
	}
	
	@Resource(name="u")
	public void setUserDAO( UserDAO userDAO) {
		this.userDAO = userDAO;
	}
	

	
	public void destroy() {
		System.out.println("destroy");
	}
}

beans.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:aop="http://www.springframework.org/schema/aop"
  xmlns:context="http://www.springframework.org/schema/context"
  
	xsi:schemaLocation="http://www.springframework.org/schema/beans
           http://www.springframework.org/schema/beans/spring-beans-3.0.xsd 
        http://www.springframework.org/schema/aop     
        http://www.springframework.org/schema/aop/spring-aop-3.0.xsd
        http://www.springframework.org/schema/context     
        http://www.springframework.org/schema/context/spring-context-3.0.xsd">   
    <context:annotation-config/>
    <context:component-scan base-package="com.bjsxt"/>     
	
 	<aop:aspectj-autoproxy></aop:aspectj-autoproxy>
 	
</beans>

Test 目录

package com.bjsxt.service;

UserServiceTest

package com.bjsxt.service;

import static org.junit.Assert.*;

import org.junit.Test;

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

import com.bjsxt.dao.UserDAO;
import com.bjsxt.model.User;

public class UserServiceTest {

	@Test
	public void testAdd() throws Exception {
		
		ClassPathXmlApplicationContext ctx = new ClassPathXmlApplicationContext("beans.xml");
		
		UserService service = (UserService) ctx.getBean("userService"); // new UserService();
		
		service.add(new User());
		
		ctx.destroy();
	}
}

UserServiceTest 2

package com.bjsxt.service;

import static org.junit.Assert.*;

import org.junit.Test;

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

import com.bjsxt.dao.UserDAO;
import com.bjsxt.model.User;

public class UserServiceTest {

	@Test
	public void testAdd() throws Exception {
		
		ClassPathXmlApplicationContext ctx = new ClassPathXmlApplicationContext("beans.xml");
		
		UserService service = (UserService) ctx.getBean("userService"); // new UserService();
		System.out.println(service.getClass());
		service.add(new User());
		
		ctx.destroy();
	}
}

写程序推荐，面向接口编程。