轉載自： http://chenjumin.iteye.com/blog/364948

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一、基礎接口和類

???? 1、Person接口的源碼

      public interface Person {
	public void info();
	public void show(String message);
}
    

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???? 2、PersonImpl類的源碼

      public class PersonImpl implements Person {
	private String name;
	private int age;
	
	public void setName(String name) {
		this.name = name;
	}

	public void setAge(int age) {
		this.age = age;
	}

	public void info() {
		System.out.println("\t我叫" + name + ",今年" + age + "歲。");
	}

	public void show(String message) {
		System.out.println(message);
	}
}

    

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??? 3、bean的配置

      <!-- 目標對象 -->
<bean id="personTarget" class="com.cjm.aop.PersonImpl">
	<property name="name" value="Raymond.chen"/>
	<property name="age" value="30"/>
</bean>

    

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二、Spring AOP支持的通知類型

???? 一）環繞通知（Around advice）

????????? 實現環繞通知需要實現org.aopalliance.intercept.MethodInterceptor接口。

?????????????? 1、PersonAroundAdvice類的源碼

      public class PersonAroundAdvice implements MethodInterceptor {
	public Object invoke(MethodInvocation invocation) throws Throwable {
		System.out.println("AroundAdvice：方法調用前");
		
		//不要忘記調用invocation的proceed方法哦
		Object result = invocation.proceed(); 
		
		System.out.println("AroundAdvice：方法調用后");
		return result;
	}
}

    

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?????????????? 2、bean配置

      <bean id="personAroundAdvice" class="com.cjm.aop.PersonAroundAdvice"/>

<!-- 代理工廠bean -->
<bean id="person" class="org.springframework.aop.framework.ProxyFactoryBean">
	<property name="proxyInterfaces" value="com.cjm.aop.Person"/>
	<property name="target" ref="personTarget"/>
	<property name="interceptorNames">
		<list>
			<value>personAroundAdvice</value>
		</list>
	</property>
</bean>

    

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?????????????? 3、測試代碼

      ApplicationContext context = new FileSystemXmlApplicationContext("classpath:com/cjm/aop/beans.xml");
Person p = (Person)context.getBean("person");  //注意這里是代理工廠Bean的ID
p.info();

    

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???? 二）前置通知（Before advice）

????????? 實現前置通知需要實現org.springframework.aop.MethodBeforeAdvice接口。

?????????????? 1、PersonBeforeAdvice類的源碼

      public class PersonBeforeAdvice implements MethodBeforeAdvice {
	public void before(Method method, Object[] args, Object target) throws Throwable {
		System.out.println("BeforeAdvice：方法調用前");
	}
}

    

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?????????????? 2、bean配置

      <bean id="personBeforeAdvice" class="com.cjm.aop.PersonBeforeAdvice"/>

<bean id="person" class="org.springframework.aop.framework.ProxyFactoryBean">
	<property name="proxyInterfaces" value="com.cjm.aop.Person"/>
	<property name="target" ref="personTarget"/>
	<property name="interceptorNames">
		<list>
			<value>personBeforeAdvice</value>
		</list>
	</property>
</bean>

    

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???? 三）返回后通知（After Returning advice）

????????? 實現返回后通知需要實現org.springframework.aop.AfterReturningAdvice接口。

?????????????? 1、PersonAfterReturningAdvice類的源碼

      public class PersonAfterReturningAdvice implements AfterReturningAdvice {
	public void afterReturning(Object returnValue, Method method, Object[] args, Object target) throws Throwable {
		System.out.println("AfterReturningAdvice：方法調用后");
	}
}

    

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?????????????? 2、bean配置

      <bean id="personAfterReturningAdvice" class="com.cjm.aop.PersonAfterReturningAdvice"/>

<bean id="person" class="org.springframework.aop.framework.ProxyFactoryBean">
	<property name="proxyInterfaces" value="com.cjm.aop.Person"/>
	<property name="target" ref="personTarget"/>
	<property name="interceptorNames">
		<list>
			<value>personAfterReturningAdvice</value>
		</list>
	</property>
</bean>

    

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?????????????? 3、以上的配置中，通知對目標對象的所有方法都會起作用。如果需要過濾掉一部分方法，可以用正則表達式切入點配置器或者方法名匹配切入點配置器實現。

      <!-- 通知與正則表達式切入點一起配置 -->
<!-- Advisor等于切入點加通知 -->
<!-- 方法名匹配切入點配置器：org.springframework.aop.support.NameMatchMethodPointcutAdvisor -->
<bean id="personPointcutAdvisor" class="org.springframework.aop.support.RegexpMethodPointcutAdvisor">
	<property name="advice" ref="personAfterReturningAdvice"/>
	<property name="patterns">
		<list>
			<value>.*info.*</value>
		</list>
	</property>
</bean>

<bean id="person" class="org.springframework.aop.framework.ProxyFactoryBean">
	<property name="proxyInterfaces" value="com.cjm.aop.Person"/>
	<property name="target" ref="personTarget"/>
	<property name="interceptorNames">
		<list>
			<value>personPointcutAdvisor</value>
		</list>
	</property>
</bean>

    

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???? 四）異常通知（Throws advice）

????????? 當連接點拋出異常時，異常通知被調用。實現異常通知需要實現org.springframework.aop.ThrowsAdvice接口，該接口不包含任何方法，但在實現該接口時必須實現如下形式的方法：
???????????????? afterThrowing([Method], [args], [target], Throwable subclass)
????????? 可以實現一個或多個這樣的方法。在這些方法中，只有第四個參數是必需的，前三個參數可選。

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????????? 1、PersonThrowsAdvice類的源碼

      public class PersonThrowsAdvice implements ThrowsAdvice {
	public void afterThrowing(FileNotFoundException ex){
		System.out.println("ThrowsAdvice >> FileNotFoundException：" + ex.toString());
	}

	public void afterThrowing(Object[] args, Exception ex){
		System.out.println("ThrowsAdvice >> Exception：" + ex.getMessage());
	}

	public void afterThrowing(Method method, Object[] args, Object target, Throwable ex){
		System.out.println("ThrowsAdvice >> Throwable：" + ex.getMessage());
	}
}

    

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??????????2、bean配置

      <bean id="personThrowsAdvice" class="com.cjm.aop.PersonThrowsAdvice"/>

<bean id="person" class="org.springframework.aop.framework.ProxyFactoryBean">
	<property name="proxyInterfaces" value="com.cjm.aop.Person"/>
	<property name="target" ref="personTarget"/>
	<property name="interceptorNames">
		<list>
			<value>personThrowsAdvice</value>
		</list>
	</property>
</bean>

    

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???? 五）引入通知（Introduction advice）

?????????? 引入通知是一種特殊的通知，它能將新的成員變量、成員方法引入到目標類中。它不能作用于任何切入點，因為它只作用于類層次，而不是方法層次。實現引入通知需要實現IntroductionAdvisor和IntroductionInterceptor接口。

?????????? 引入通知不能調用proceed方法。Advisor必須針對每個實例，并且是有狀態的。

?????????? 引入通知的效果類似于設計模式中的訪問者模式（Visitor Pattern）。

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???????????1、Lockable接口的源碼

      public interface Lockable {
	void lock();
	void unlock();
	boolean locked();
}

    

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?????????? 2、LockableImpl類的源碼

      public class LockableImpl extends DelegatingIntroductionInterceptor implements Lockable {
	private boolean locked;
	
	public void lock() {
		this.locked = true;
	}

	public void unlock() {
		this.locked = false;
	}

	public boolean locked() {
		return this.locked;
	}

	@Override
	public Object invoke(MethodInvocation invocation) throws Throwable {
		if(this.locked){
			throw new RuntimeException("加鎖，無法執行");
		}
		
		//這里不能調用invocation的proceed方法
		//通常不需要改寫invoke方法，直接調用父類的該方法即可
		return super.invoke(invocation);
	}
}

    

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?????????? 3、PersonIntroductionAdvice類的源碼

      public class PersonIntroductionAdvice extends DefaultIntroductionAdvisor {
	public PersonIntroductionAdvice(){
		super(new LockableImpl(), Lockable.class);
	}
}

    

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?????????? 4、bean配置

      <!-- Advice必須針對每個實例，所以scope要設為prototype -->
<bean id="personIntroductionAdvice" class="com.cjm.aop.introduction.PersonIntroductionAdvice" scope="prototype"/>

<bean id="person" class="org.springframework.aop.framework.ProxyFactoryBean">
	<property name="proxyInterfaces" value="com.cjm.aop.Person"/>
	<property name="target" ref="personTarget"/>
	<property name="interceptorNames">
		<list>
			<value>personIntroductionAdvice</value>
		</list>
	</property>
</bean>

    

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?????????? 5、測試代碼