Spring学习——AOP切面

柔情只为你懂 2022-05-13 07:46 204阅读 0赞

**AOP面向切面编程**(Aspect Oriented Programming)，通过**预编译**方式和**运行期动态代理**实现程序功能的统一维护的一种技术

可以对业务逻辑的各个部分进行**隔离**，从而使得业务逻辑各部分之间的**耦合度降低**，提高程序的**可重用性**，同时提高了**开发的效率**

AOP需要在beans.xml中单独配置，包括<beans/>中的aop路径和config配置标签

1、通过xml配置

<?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-3.0.xsd 
        http://www.springframework.org/schema/aop 
        http://www.springframework.org/schema/aop/spring-aop-3.0.xsd ">
    
       
       	<aop:config>
       		
       		<aop:aspect id="log" ref="logBean">
       			
       			<aop:pointcut expression="execution(* com.spring.Aop.demoXML.*.*(..))" id="point" />
       			
       			
       			<aop:before method="before" pointcut-ref="point"/>
       			
       			
       			<aop:after method="after" pointcut-ref="point"/>
       			
       			<aop:after-returning method="afterReturning" pointcut-ref="point"  returning="result"/>
       			
       			
       		</aop:aspect>
       	</aop:config>
       	
    	<bean id="user" class="com.spring.Aop.demoXML.User">
    		<property name="username" value="admin"/>
    		<property name="password" value="123456"/>    
    	</bean>
    	<bean id="logBean" class="com.spring.Aop.demoXML.Log"></bean>
    	
    </beans>

切面处理类

package com.spring.Aop.demoXML;
    
    public class Log {
    	public void before(){
    		System.out.println("before之前");
    	}
    	public void after(){
    		System.out.println("after之后");
    	}
    	
    	public void afterReturning(Object result){
    		System.out.println("afterReturning:"+result);
    	}
    	
    	public void afterThrowing(Exception exception){
    		System.out.println("afterThrowing:"+exception.toString());
    	}
    }

切面类

package com.spring.Aop.demoXML;
    
    public class User {
    	private String username;
    	private String password;
    	public String getUsername() {
    		System.out.println("getUsername:"+username);
    		return username;
    	}
    	public void setUsername(String username) {
    		System.out.println("setUsername:"+username);
    		this.username = username;
    	}
    	public String getPassword() {
    		System.out.println("getPassword:"+password);
    		return password;
    	}
    	public void setPassword(String password) {
    		System.out.println("setPassword:"+password);
    		this.password = password;
    	}
    	
    }

主函数类

package com.spring.Aop.demoXML;
    
    import org.springframework.context.ApplicationContext;
    import org.springframework.context.support.ClassPathXmlApplicationContext;
    
    public class SpringMain {
    	public static void main(String[] args){
    		ApplicationContext context = new ClassPathXmlApplicationContext("BeansXML.xml");
    		User user = (User) context.getBean("user");
    		System.out.println("-----------------------------");
    		//User user = new User();
    		user.getUsername();
    		System.out.println("-----------------------------");
    		user.getPassword();
    		System.out.println("-----------------------------");
    		user.setUsername("admin1");
    		System.out.println("-----------------------------");
    		user.setPassword("123451");
    		System.out.println("-----------------------------");
    		user.getUsername();
    		System.out.println("-----------------------------");
    		user.getPassword();
    	}
    }

2、使用注解配置

log切面类

package com.spring.Aop.demoAnnotation;
    
    import org.aspectj.lang.annotation.After;
    import org.aspectj.lang.annotation.AfterReturning;
    import org.aspectj.lang.annotation.Aspect;
    import org.aspectj.lang.annotation.Before;
    import org.aspectj.lang.annotation.Pointcut;
    
    @Aspect
    public class Log {
    	
    	@Pointcut("execution(* com.spring.Aop.demoAnnotation.User.*(..))")
    	public void logging(){System.out.println("pointcut切入点");}
    	
    	@Before("logging()")
    	public void before(){
    		System.out.println("before之前");
    	}
    	@After("logging()")
    	public void after(){
    		System.out.println("after之后");
    	}
    	@AfterReturning(pointcut="logging()", returning="result")
    	public void afterReturning(Object result){
    		System.out.println("afterReturning:"+result);
    	}
    }