菜鸟学习Spring——60s利用JoinPoint获取参数的值和方法名称
最后更新于：2022-04-01 09:34:09
## 一、概述
AOP的实现方法在上两篇博客中已经用了两种方法来实现现在的问题来了虽然我们利用AOP，那么客户端如何信息传递？利用JoinPoint接口来实现客户端给具体实现类的传递参数。
## 二、代码演示。
目录结构：
SecurityHandler.java
~~~
package com.tgb.spring;
import org.aspectj.lang.JoinPoint;
public class SecurityHandler{
private void checkSecurity(JoinPoint joinPoint){
for (int i = 0; i < joinPoint.getArgs().length; i++) {
System.out.println(joinPoint.getArgs()[i]);
}
System.out.println(joinPoint.getSignature().getName());
System.out.println("=====checkSecurity====");
}
}
~~~
Client.java
~~~
package com.tgb.spring;
import org.springframework.beans.factory.BeanFactory;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import com.tgb.spring.UserManager;
public class Client {
public static void main(String[] args) {
BeanFactory factory=new ClassPathXmlApplicationContext("applicationContext.xml");
UserManager userManager=(UserManager) factory.getBean("userManager");
userManager.addUser("张三", "123");
//userManager.delUser(1);
}
}
~~~
UserManager.java
~~~
package com.tgb.spring;
public interface UserManager {
public void addUser(String username,String password);
public void delUser(int userId);
public String findUserById(int userId);
public void modifyUser(int userId,String username,String password);
}
~~~
UserManagerImpl.java
~~~
package com.tgb.spring;
public class UserManagerImpl implements UserManager {
public void addUser(String username, String password) {
//checkSecurity();
System.out.println("===UserManager.addUser===");
}
public void delUser(int userId) {
//checkSecurity();
System.out.println("===UserManager.delUser===");
}
public String findUserById(int userId) {
//checkSecurity();
System.out.println("===UserManager.findUserById===");
return "张三";
}
public void modifyUser(int userId, String username, String password) {
//checkSecurity();
System.out.println("===UserManager.modifyUser===");
}
// private void checkSecurity(){
// System.out.println("checkSecurity");
//
// }
}
~~~
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"
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">
<bean id="userManager" class="com.tgb.spring.UserManagerImpl" />
<bean id="securityHandler" class="com.tgb.spring.SecurityHandler"/>
<aop:config>
<aop:aspect id="securityAspect" ref="securityHandler">
<aop:pointcut id="addAddMethod" expression="execution(* com.tgb.spring.*.*(..))" />
<aop:before method="checkSecurity" pointcut-ref="addAddMethod" />
</aop:aspect>
</aop:config>
</beans>
~~~
效果图：
## 三、总结。
我们可以通过Advice中添加一个JoinPoint参数，这个值会由spring自动传入，从JoinPoint中可以取得。