一个简单的Spring的AOP例子（JAVA面向切面编程）
公司要求分享技术，一个小组九个人，每周一个人，想想讲讲AOP吧，用处也挺大的，果断写了一个小例子，改了改也就成了。这是个简单AOP例子，包括前置通知，后置通知，环绕通知，和目标对象。
目标对象的接口:IStudent.java
package com.dragon.study;
/**
* @author ysm
*/
public interface IStudent {
public void addStudent(String name);
}
目标类:StudentImpl.java
package com.dragon.study.Impl;
import com.dragon.study.IStudent;
/**
* @author ysm
*/
public class StudentImpl implements IStudent {
public void addStudent(String name) {
System.out.println( " 欢迎 " + name + " 加入Spring家庭! " );
}
}
前置通知:BeforeAdvice.java
package com.dragon.Advice;
import java.lang.reflect.Method;
import org.springframework.aop.MethodBeforeAdvice;
/**
* @author ysm
*/
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.dragon.Advice;
import java.lang.reflect.Method;
import org.springframework.aop.AfterReturningAdvice;
/**
* @author ysm
*/
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.dragon.Advice;
import org.aopalliance.intercept.MethodInterceptor;
import org.aopalliance.intercept.MethodInvocation;
/**
* @author ysm
*/
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("ysm")){
//如果学生是ysm时,执行目标方法,
result= invocation.proceed();
} else{
System.out.println("此学生是"+stu_name+"而不是ysm,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.dragon.Advice.BeforeAdvice"></bean>
<bean id="afterAdvice" class="com.dragon.Advice.AfterAdvice"></bean>
<bean id="compareInterceptor" class="com.dragon.Advice.CompareInterceptor"></bean>
<bean id="studenttarget" class="com.dragon.study.Impl.StudentImpl"></bean>
<bean id="student" class="org.springframework.aop.framework.ProxyFactoryBean">
<property name="proxyInterfaces">
<value>com.dragon.study.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;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.FileSystemXmlApplicationContext;
import com.dragon.study.IStudent;
/**
* @author ysm
*/
public class Test {
/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
ApplicationContext ctx = new FileSystemXmlApplicationContext("/com/dragon/applicationContext.xml");
IStudent person = (IStudent)ctx.getBean("student");
person.addStudent("ysm");
//person.addStudent("javadragon");
}
}