Spring AOP及MethodInterceptor拦截器实现方法拦截以及切入点函数阻止执行

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项目中需要修改IM信息送以及短信发送，要求已离职的人员不呢收到IM信息和短信

因为在项目中各个地方都有使用到短信和IM信息通知;所以想到使用Spring AOP进行实现，以及拦截器进行实现，一下为两种方法的具体实现代码:
1)Spsing AOP

需要被织入的切面类:ppackage com.rhxy.utils;

import com.rhxy.bean_new.personnel.Employee;
import com.rhxy.bean_new.personnel.User;
import com.rhxy.dao_new.EmployeeDAO;
import com.rhxy.dao_new.UserDAO;
import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;

/**
* Created by Administrator on 2016/11/4 0004.
*/
//声明这是一个切面Bean
@Aspect
public class SendMsgAspect {
@Before("execution(* com.rhxy.pushMsg.PushMsg.sendMsg(..))")
Object before(JoinPoint joinPoint) {
Object[] args = joinPoint.getArgs();
try {
if (args.length >= 2) {
String IMAccount = (String) args[2];
UserDAO userDAO = (UserDAO) Utils.getBean("userDAO");
if (null != userDAO) {
User user = userDAO.getUsersByIMAccount(IMAccount);
if (null != user) {
EmployeeDAO employeeDAO = (EmployeeDAO) Utils.getBean("employeeDAO");
Employee employee = employeeDAO.get(user.getEmployeeId());
//这里进行业务逻辑判断通过IMAcount信息获取到员工,如果该员工状态为离职，则将IMAcount修改空也就是args[2];并且抛出异常由try{}catch捕捉该异常
//否则不做任何操作，直接返回
if (employee == null || employee.getEntry() == null || employee.getEntry().getStatus() == null || "离职".equals(employee.getEntry().getStatus())) {
args[2] = "";
throw new RuntimeException(employee.getName() + "：该员工已离职通知失败!");
}
}
}
}
} catch (Exception e) {
//扑捉到异常后 pjp.proceed(args)将args 也就是修改后的参数传给目标函数这里的目标函数是指被切入点的函数
//需要注意的是,如果是使用了pjp.proceed(args) 目标函数会被执行两次正是因为这点所以接着写了另一个具有相同功能的拦截器
ProceedingJoinPoint pjp = (ProceedingJoinPoint) joinPoint;
Object retVal = null;
try {
retVal = pjp.proceed(args);
} catch (Throwable throwable) {
throwable.printStackTrace();
}
return retVal;
}
return null;
}
}

applicationContext.xml配置文件修改配置文件中添加以下内容：

<bean id="sendMsgAop" class="com.rhxy.utils.SendMsgAspect">
</bean>
<aop:config>

<aop:pointcut id="aroundPointcutTarget"
expression="execution(* com.rhxy.pushMsg.PushMsg.sendMsg(..))"/>

<aop:aspect id="userAspect" ref="sendMsgAop">

<aop:before method="before" pointcut-ref="aroundPointcutTarget"/>

</aop:aspect>
</aop:config>

2)MethodInterceptor拦截器

拦截器类package com.rhxy.utils;

import com.rhxy.bean_new.personnel.Employee;
import com.rhxy.bean_new.personnel.User;
import com.rhxy.dao_new.EmployeeDAO;
import com.rhxy.dao_new.UserDAO;
import org.aopalliance.intercept.MethodInterceptor;
import org.aopalliance.intercept.MethodInvocation;

import java.lang.reflect.Method;

/**
* Created by Administrator on 2016/11/5 0005.
*/
public class SendMsgInterceptor implements MethodInterceptor {
@Override
public Object invoke(MethodInvocation invo) throws Throwable {
Object[] args = invo.getArguments();
Method method = invo.getMethod();
if (!"sendMsg".equals(method.getName())) {
Object obj = invo.proceed();
return obj;
}
try {
if (args.length >= 2) {
String IMAccount = (String) args[2];
UserDAO userDAO = (UserDAO) Utils.getBean("userDAO");
if (null != userDAO) {
User user = userDAO.getUsersByIMAccount(IMAccount);
if (null != user) {
EmployeeDAO employeeDAO = (EmployeeDAO) Utils.getBean("employeeDAO");
Employee employee = employeeDAO.get(user.getEmployeeId());
//业务逻辑判断通过IMAcount信息获取到员工,如果该员工状态不为离职的情况下，通过 invo.proceed();它来对目标对象方法调用，返回一个Object对象。
//否则不做任何操作，直接返回
if (employee != null && employee.getEntry() != null && employee.getEntry().getStatus() != null && !"".equals(employee.getEntry().getStatus())) {
Object obj = invo.proceed();
return obj;
}
}
}
}
} catch (Exception e) {
e.printStackTrace();
}
return args;
}
}applicationContext.xml配置文件修改<bean id="myInterceptor"
class="com.rhxy.utils.SendMsgInterceptor"
abstract="false" lazy-init="default"
autowire="default">
</bean>
















<bean class="org.springframework.aop.framework.autoproxy.BeanNameAutoProxyCreator">
<property name="beanNames">

<list><value>pushMsg</value></list>
</property>
<property name="interceptorNames">
<list>
<value>myInterceptor</value>
</list>
</property>
</bean>

第二种不会造成目标函数第二次执行

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