本文的AOP例子,包括前置通知,后置通知,环绕通知,和目标对象。写这个例子的主要目标只是想让想学AOP的能更快地入门,了解一下如何去配置AOP里面的一些信息。
目标对象的接口:IStudent.javapackage com.log4jAop;
public interface IStudent {
public void addStudent(String name);
}
目标类:StudentImpl.java
package com.log4jAop;
public class StudentImpl implements IStudent {
public void addStudent(String name) {
System.out.println( " 欢迎 " + name + " 你加入Spring家庭! " );
}
}
前置通知:BeforeAdvice.java
package com.log4jAop;
import java.lang.reflect.Method;
import org.springframework.aop.MethodBeforeAdvice;
public class BeforeAdvice implements MethodBeforeAdvice {
public void before(Method method,Object[] args, Object target)
throws Throwable {
System.out.println( " 这是BeforeAdvice类的before方法. " );
}
}
后置通知:AfterAdvice.java
package com.log4jAop;
import java.lang.reflect.Method;
import org.springframework.aop.AfterReturningAdvice;
public class AfterAdvice implements AfterReturningAdvice{
public void afterReturning(Object returnValue ,Method method,
Object[] args,Object target) throws Throwable{
System.out.println("这是AfterAdvice类的afterReturning方法.");
}
}
环绕通知:CompareInterceptor.java
package com.log4jAop;
import org.aopalliance.intercept.MethodInterceptor;
import org.aopalliance.intercept.MethodInvocation;
public class CompareInterceptor implements MethodInterceptor{
public Object invoke(MethodInvocation invocation) throws Throwable{
Object result = null;
String stu_name = invocation.getArguments()[0].toString();
if ( stu_name.equals("dragon")){
result= invocation.proceed();
} else{
System.out.println("此学生是"+stu_name+"而不是dragon,不批准其加入.");
}
return result;
}
}
配置文件applicationContext.xml
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN" "http://www.springframework.org/dtd/spring-beans.dtd">
<beans>
<bean id="beforeAdvice" class="com.log4jAop.BeforeAdvice"></bean>
<bean id="afterAdvice" class="com.log4jAop.AfterAdvice"></bean>
<bean id="compareInterceptor" class="com.log4jAop.CompareInterceptor"></bean>
<bean id="studenttarget" class="com.log4jAop.StudentImpl"></bean>
<bean id="student"
class="org.springframework.aop.framework.ProxyFactoryBean">
<property name="proxyInterfaces">
<value>com.log4jAop.IStudent</value>
</property>
<property name="interceptorNames">
<list>
<value>beforeAdvice</value>
<value>afterAdvice</value>
<value>compareInterceptor</value>
</list>
</property>
<property name="target">
<ref bean="studenttarget" />
</property>
</bean>
</beans>
现在开始写测试类,Test.java
package com.log4jAop;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.FileSystemXmlApplicationContext;
public class Test {
/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
ApplicationContext ctx =
new FileSystemXmlApplicationContext("src/main/java/com/applicationContext.xml");
IStudent person = (IStudent)ctx.getBean("student");
person.addStudent("dragon");
}
}
最终的目录结构如图:
pom.xml记得导入相应的库:
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.log4j</groupId>
<artifactId>com.log4j</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
<name>com.log4j</name>
<url>http://maven.apache.org</url>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
</properties>
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>3.8.1</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>4.3.17.RELEASE</version>
</dependency>
</dependencies>
</project>
内容参考了:http://www.blogjava.net/javadragon/archive/2006/12/03/85115.html,亲测好用