SSM（十六）AOP实现自动的系统日志功能

一、要求

在业务功能执行前后，添加日志功能。

二、步骤

1. 在项目中添加Spring AOP的jar文件

2. 编写前置增强和后置增强实现日志功能

3. 编写Spring配置文件，对业务方法进行增强处理

4. 编写代码获取带有增强处理的业务对象

三、代码

UserDao.java

package dao;

import entity.User;

public interface UserDao {
	public void saveUser(User user);
}

UserDaoImpl.java

package dao.impl;

import dao.UserDao;
import entity.User;

public class UserDaoImpl implements UserDao {

	@Override
	public void saveUser(User user) {
		System.out.println("保存用户信息到数据库");
	}

}

UserService.java

package service;

import entity.User;

public interface UserService {
	public void addNewUser(User user);
}

UserServiceImpl.java

package service.impl;

import dao.UserDao;
import entity.User;
import service.UserService;

public class UserServiceImpl implements UserService {

	private UserDao dao;

	public void setDao(UserDao dao) {
		this.dao = dao;
	}

	@Override
	public void addNewUser(User user) {
		dao.saveUser(user);
	}

}

User.java

package entity;

public class User {
	private Integer id;
	private String username;
	private String password;
	private String email;

	public User() {
		super();
	}

	public User(Integer id, String username, String password, String email) {
		super();
		this.id = id;
		this.username = username;
		this.password = password;
		this.email = email;
	}

	public Integer getId() {
		return id;
	}

	public void setId(Integer id) {
		this.id = id;
	}

	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;
	}

	public String getEmail() {
		return email;
	}

	public void setEmail(String email) {
		this.email = email;
	}

}

UserServiceLogger.java

package aop;

import java.util.Arrays;

import org.apache.log4j.Logger;
import org.aspectj.lang.JoinPoint;


/**
 * 增强处理类
 * @author xie
 *
 */
public class UserServiceLogger {
	private static Logger log = Logger.getLogger(UserServiceLogger.class);
	public void before(JoinPoint jp) {
		log.info("类：" + jp.getTarget()+ "，方法：" + jp.getSignature() + "，参数" + Arrays.toString(jp.getArgs()));
	}
	
	public void afterReturning(JoinPoint jp, String result) {
		log.info("类：" + jp.getTarget()+ "，方法：" + jp.getSignature() + "， 返回值" + result);
	}
}

ApplicationContext.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"
     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.xsd">
	<bean id="userDao" class="dao.impl.UserDaoImpl"></bean>
	<bean id="userService" class="service.impl.UserServiceImpl">
		<property name="dao" ref="userDao"></property>
	</bean>
	
	<bean id="log" class="aop.UserServiceLogger"></bean>
	
	<aop:config>
		<aop:pointcut id="addNewUser" expression="j)" />
		
		<aop:aspect id="add" ref="log">
			<aop:before method="before" pointcut-ref="addNewUser"/>
			<aop:after-returning method="afterReturning" pointcut-ref="addNewUser" returning="result"/>
		</aop:aspect>
		
	</aop:config>
</beans>

AopTest.java

package test;

import static org.junit.jupiter.api.Assertions.*;

import org.junit.jupiter.api.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import entity.User;
import service.UserService;

class AopTest {

	@Test
	void test() {
		ApplicationContext context = new ClassPathXmlApplicationContext("ApplicationContext.xml");
		UserService userService = (UserService) context.getBean("userService");
		User user = new User(1,"z3","123","z3@xxx.com");
		userService.addNewUser(user);
	}

}