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spring aop advice

2016-05-04 18:06 525 查看
1.前置通知(BeforeAdvice):

import java.lang.reflect.Method;

import org.springframework.aop.MethodBeforeAdvice;

public class HelloBeforeAdvice implements MethodBeforeAdvice{

public void before(Method method, Object[] args, Object target) throws Throwable {
System.out.println("do something before some method");
}
}


如果出现 The hierarchy of the type HelloBeforeAdvice is inconsistent错误 , 是缺少相关的jar或者jdk环境不对。

2.后置通知(AfterAdvice)

import java.lang.reflect.Method;

import org.springframework.aop.AfterReturningAdvice;

public class HelloAfterAdvice implements AfterReturningAdvice {

public void afterReturning(Object result, Method method, Object[] args, Object target) throws Throwable {
System.out.println("do something after the method");
}

}


3. Test client

import org.springframework.aop.framework.ProxyFactory;

public class TestClient {

public static void main(String[] args) {
ProxyFactory proxyFactory = new ProxyFactory();//创建代理工厂
proxyFactory.setTarget(new HelloImpl());
proxyFactory.addAdvice(new HelloBeforeAdvice());
proxyFactory.addAdvice(new HelloAfterAdvice());
Hello helloProxy = (Hello) proxyFactory.getProxy();
System.out.println(helloProxy.sayHello("zhangsan"));
}
}

----------------------------
public class HelloImpl implements Hello {

public String sayHello(String str) {
System.out.println("hello>>>"+str);
return "hello>>>"+str;
}
}


4. 环绕通知(AroundAdvice)

//aop联盟提供的接口
import org.aopalliance.intercept.MethodInterceptor;
import org.aopalliance.intercept.MethodInvocation;

public class HelloAroundAdvice implements MethodInterceptor {

public Object invoke(MethodInvocation invocation) throws Throwable {
System.out.println("before method>>>");
Object result = invocation.proceed();
System.out.println("after method>>");
return result;
}
}


5. spring 配置文件方式

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans" xmlns:context="http://www.springframework.org/schema/context"
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" xmlns:p="http://www.springframework.org/schema/p"
xmlns:util="http://www.springframework.org/schema/util" xmlns:jdbc="http://www.springframework.org/schema/jdbc"
xmlns:cache="http://www.springframework.org/schema/cache"
xsi:schemaLocation=" http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd http://www.springframework.org/schema/jdbc http://www.springframework.org/schema/jdbc/spring-jdbc.xsd http://www.springframework.org/schema/cache http://www.springframework.org/schema/cache/spring-cache.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util.xsd">
<!-- 自动扫描ppms包 ,将带有注解的类 纳入spring容器管理 -->
<context:component-scan base-package="com.cdv.ppms"></context:component-scan>

<bean id="helloProxy" class="org.springframework.aop.framework.ProxyFactoryBean">
<property name="interfaces" value="com.cdv.ppms.Hello"/><!-- 需要代理的接口 -->
<property name="target" ref="helloImpl"/><!-- 接口实现类 , 此处需要是ref 否则object is not an instance of declaring class-->
<property name="interceptorNames"><!-- 拦截器 名称-->
<list>
<value>helloAroundAdvice</value>
</list>
</property>
</bean>
   <bean id="helloImpl" class="com.cdv.ppms.HelloImpl"></bean>
</beans>


import org.springframework.stereotype.Component;

@Component
public class HelloImpl implements Hello {
//...
}

@Component
public class HelloAroundAdvice implements MethodInterceptor {
//....
}


import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class TestXMLClient {

public static void main(String[] args) {
ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
Hello    hello = (Hello) context.getBean("helloProxy");
hello.sayHello("test xml");
}
}


6. 抛出通知(ThrowAdvice)

import java.lang.reflect.Method;
import org.springframework.aop.ThrowsAdvice;
import org.springframework.stereotype.Component;

@Component
public class HelloThrowAdvice implements ThrowsAdvice{
public void afterThrowing(Method method, Object[] args, Object target, Exception e){
System.out.println("-------------------Throw Exception------------------------");
System.out.println("target class>>"+target.getClass().getName());
System.out.println("method class>>" + method.getName());
System.out.println("exception message>>"+e.getMessage());
System.out.println("-------------------Throw Exception------------------------");
}
}


<bean id="helloProxy" class="org.springframework.aop.framework.ProxyFactoryBean">
<property name="interfaces" value="com.cdv.ppms.Hello"/><!-- 需要代理的接口 -->
<property name="target" ref="helloImpl"/><!-- 接口实现类 -->
<property name="interceptorNames"><!-- 拦截器 名称-->
<list>
<value>helloAroundAdvice</value>
<value>testThrowAdvice</value>
</list>
</property>
</bean>


import org.springframework.stereotype.Component;

@Component
public class HelloImpl implements Hello {

public String sayHello(String str) {
System.out.println("hello>>>"+str);
throw new RuntimeException("error>>");//加入异常以便测试
}
}


7. 引入通知(Introduction Advice)

对方法的增强叫织入(Weaving),对类的增强叫引入(Introduction)

import org.aopalliance.intercept.MethodInvocation;
import org.springframework.aop.support.DelegatingIntroductionInterceptor;
import org.springframework.stereotype.Component;
@Component
public class HelloIntroAdvice extends DelegatingIntroductionInterceptor implements Apology {

/**
*
*/
private static final long serialVersionUID = -3328637206414010549L;

public Object invoke(MethodInvocation invocation) throws Throwable{

return super.invoke(invocation);
}

public void saySorry(String str) {
System.out.println("introduction advice>>>"+str);
}
}


<bean id="helloProxy" class="org.springframework.aop.framework.ProxyFactoryBean">
<property name="interfaces" value="com.cdv.ppms.Apology"/><!-- 需要代理的接口 -->
<property name="target" ref="helloImpl"/><!-- 接口实现类 -->
<property name="interceptorNames"><!-- 拦截器 名称-->
<list>
<value>helloAroundAdvice</value>
<value>helloThrowAdvice</value>
<value>helloIntroAdvice</value>
</list>
</property>
<property name="proxyTargetClass" value="true"></property><!--代理目标类, 默认false代理接口-->
</bean>
<bean id="helloImpl" class="com.cdv.ppms.HelloImpl"></bean>


import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class TestXMLClient {

public static void main(String[] args) {
ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
HelloImpl    helloImpl = (HelloImpl) context.getBean("helloProxy");
helloImpl.sayHello("test xml");
Apology apology = (Apology) helloImpl;//将目标类向上强制转型为Apology接口, 这时引入通知给我们带来的特性, 也就是“接口动态实现”功能
apology.saySorry("zhangsan");
}
}


8. 切面(Advisor)

切面(Advisor)封装了通知(Advice)和切点(Pointcut)

import org.springframework.stereotype.Component;

@Component
public class HelloImpl implements Hello {

public String sayHello(String str) {
System.out.println("hello>>>"+str);
return str;
}

public void advisorOne(String name){
System.out.println("advisor one>>>"+name);
}

public void advisorTwo(String name){
System.out.println("advisor two>>"+name);
}
}


在代理类中新增以advisor开头的方法,对其进行拦截

<context:component-scan base-package="com.cdv.ppms"></context:component-scan>
    <!--定义切面-->
<bean id="helloAdvisor" class="org.springframework.aop.support.RegexpMethodPointcutAdvisor">
<property name="advice" ref="helloAroundAdvice"/>
<property name="pattern" value="com.cdv.ppms.HelloImpl.advisor.*"></property><!-- 切点 (正则表达式) -->
</bean>
<bean id="helloProxy" class="org.springframework.aop.framework.ProxyFactoryBean">
<property name="target" ref="helloImpl"/><!-- 接口实现类 -->
<property name="interceptorNames" value="helloAdvisor"/>
<property name="proxyTargetClass" value="true"></property>
</bean>
<bean id="helloImpl" class="com.cdv.ppms.HelloImpl"></bean>
<bean id="helloAroundAdvice" class="com.cdv.ppms.HelloAroundAdvice"></bean>


import org.aopalliance.intercept.MethodInterceptor;
import org.aopalliance.intercept.MethodInvocation;
import org.springframework.stereotype.Component;
@Component
public class HelloAroundAdvice implements MethodInterceptor {

public Object invoke(MethodInvocation invocation) throws Throwable {
System.out.println("before method>>>");
Object result = invocation.proceed();
System.out.println("after method>>");
return result;
}
}


import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class TestXMLClient {

public static void main(String[] args) {
ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
HelloImpl    helloImpl = (HelloImpl) context.getBean("helloProxy");
helloImpl.advisorOne("11111111");
helloImpl.advisorTwo("2222222222");

}
}
-------------around包了两层, 有问题-------------------------------------------
before method>>>
before method>>>
advisor one>>>11111111
after method>>
after method>>
before method>>>
before method>>>
advisor two>>2222222222
after method>>
after method>>
------------------------


随着项目的扩大, 上述的代理配置会越来越多。

9. 自动代理(扫描bean名称)

定义BeanNameAutoProxyCreator,该bean是个bean后处理器,无需被引用,因此没有id属性

<context:component-scan base-package="com.cdv.ppms"></context:component-scan>

<bean class="org.springframework.aop.framework.autoproxy.BeanNameAutoProxyCreator">
<property name="beanNames" value="*Impl"/><!--对以Impl结尾的类进行处理-->
<property name="interceptorNames" value="helloAroundAdvice"/>
<property name="optimize" value="true"/>
</bean>

<bean id="helloImpl" class="com.cdv.ppms.HelloImpl"></bean>
<bean id="helloAroundAdvice" class="com.cdv.ppms.HelloAroundAdvice"></bean>


测试

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class TestXMLClient {

public static void main(String[] args) {
ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
HelloImpl    helloImpl = (HelloImpl) context.getBean("helloImpl");
helloImpl.advisorOne("11111111");//
helloImpl.advisorTwo("2222222222");
helloImpl.sayHello("zhangwuji");
}
}


10. 自动代理(扫描切面配置)

代理将由DefaultAdvisorAutoProxyCreator自动生成,这个类可以扫描所有的切面类

<context:component-scan base-package="com.cdv.ppms"></context:component-scan>
<bean id="helloAdvisor" class="org.springframework.aop.support.RegexpMethodPointcutAdvisor">
<property name="advice" ref="helloAroundAdvice"/>
<property name="pattern" value="com.cdv.ppms.HelloImpl.advisor.*"/>
</bean>
<bean class="org.springframework.aop.framework.autoproxy.DefaultAdvisorAutoProxyCreator">
<property name="optimize" value="true"/>
</bean>
<bean id="helloImpl" class="com.cdv.ppms.HelloImpl"></bean>
<bean id="helloAroundAdvice" class="com.cdv.ppms.HelloAroundAdvice"></bean>


测试

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class TestXMLClient {

public static void main(String[] args) {
ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
HelloImpl    helloImpl = (HelloImpl) context.getBean("helloImpl");
helloImpl.advisorOne("11111111");
helloImpl.advisorTwo("2222222222");
helloImpl.sayHello("zhangwuji");
}
}
//只有符合advisor开头的方法才会被代理


这样在spring的配置中会存在大量的切面配置(想拦截指定注解的方法,就必须拓展DefaultPointcutAdvisor类,自定义一个切面类)。

11. Spring & AspectJ

11-1 基于注解 :通过execution()表达式 拦截方法

import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.springframework.stereotype.Component;

@Aspect
@Component
public class HelloAspect {

@Around("execution(* com.cdv.ppms.HelloImpl.*(..))")//切点表达式
public Object around(ProceedingJoinPoint pjp) throws Throwable{
before();
Object result = pjp.proceed();
after();
return result;
}

private void after() {
System.out.println("hey,, after.");

}

private void before() {
System.out.println("hey,, before");
}
}


切点表达式

execution()表示拦截的方法, 挂号中定义拦截的规则

上面第一个*表示返回任意类型

第二个*表示HelloImpl类中的任意方法

..表示任意类型参数

<context:component-scan base-package="com.cdv.ppms"></context:component-scan>
<aop:aspectj-autoproxy proxy-target-class="true"/><!-- 默认值为false只能代理接口,当为true时才能代理目标类 -->
<bean id="helloImpl" class="com.cdv.ppms.HelloImpl"></bean>


test

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class TestXMLClient {

public static void main(String[] args) {
ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
HelloImpl    helloImpl = (HelloImpl) context.getBean("helloImpl");
helloImpl.advisorOne("11111111");
helloImpl.advisorTwo("2222222222");
helloImpl.sayHello("zhangwuji");
}
}


11-2 基于注解 通过AspectJ @annotation表达式拦截方法

自定义注解

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

@Target(ElementType.METHOD)
@Retention(RetentionPolicy.RUNTIME)
public @interface MyTag {

}


更改aspect类的切点表达式

import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.springframework.stereotype.Component;

@Aspect
@Component
public class HelloAspect {

@Around("@annotation(com.cdv.ppms.MyTag)")
public Object around(ProceedingJoinPoint pjp) throws Throwable{
before();
Object result = pjp.proceed();
after();
return result;
}

private void after() {
System.out.println("hey,, after.");

}

private void before() {
System.out.println("hey,, before");
}
}


该注解可以标注在方法上,运行时生效

import org.springframework.stereotype.Component;

@Component
public class HelloImpl implements Hello {

public String sayHello(String str) {
System.out.println("hello>>>"+str);
return str;
}
@MyTag
public void advisorOne(String name){
System.out.println("advisor one>>>"+name);
}
public void advisorTwo(String name){
System.out.println("advisor two>>"+name);
}
}


配置

<context:component-scan base-package="com.cdv.ppms"></context:component-scan>
<bean id="helloImpl" class="com.cdv.ppms.HelloImpl"></bean>


测试

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class TestXMLClient {

public static void main(String[] args) {
ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
HelloImpl    helloImpl = (HelloImpl) context.getBean("helloImpl");
helloImpl.advisorOne("11111111");
helloImpl.advisorTwo("2222222222");
helloImpl.sayHello("zhangwuji");
}
}


其他几个注解

@Before @After @AfterThrowing @DeclareParents引入通知 AfterReturning(返回后通知,在方法结束后执行)

11-3 引入通知

Aspect类

import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.DeclareParents;
import org.springframework.stereotype.Component;

@Aspect
@Component
public class HelloAspect {
    //something need to do
@DeclareParents(value="com.cdv.ppms.HelloImpl",defaultImpl=com.cdv.ppms.ApologyImpl.class)
private Apology apology;

}


接口实现类

public class ApologyImpl implements Apology {

public void saySorry(String str) {
System.out.println("apologyImpl>>>"+str);
}
}


配置

   <context:component-scan base-package="com.cdv.ppms"></context:component-scan>
<bean id="helloImpl" class="com.cdv.ppms.HelloImpl"></bean>


测试

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class TestXMLClient {

public static void main(String[] args) {
ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
HelloImpl    helloImpl = (HelloImpl) context.getBean("helloImpl");
helloImpl.sayHello("zhangwuji");
Apology apology = (Apology) helloImpl;
apology.saySorry("hahahahah");
}
}
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