Spring3核心技术之AOP配置

● <aop:pointcut>：用来定义切入点，该切入点可以重用；
● <aop:advisor>：用来定义只有一个通知和一个切入点的切面；
● <aop:aspect>：用来定义切面，该切面可以包含多个切入点和通知，而且标签内部的通知和切入点定义是无序的；和advisor的区别就在此，advisor只包含一个通知和一个切入点。

Java代码

public class Interceptor {

public void beforeDomain() {
System.out.println("This is beforeDomain....");
}

public void afterDomain() {
System.out.println("This is afterDomain....");
}

public void afterReturning() {
System.out.println("This is afterReturning....");
}

public void afterThrowing() {
System.out.println("This is afterThrowing....");
}

public Object around(ProceedingJoinPoint pjp) throws Throwable {
System.out.println("===========around before advice");
Object retVal = pjp.proceed(new Object[] {"【环绕通知】"});
System.out.println("===========around after advice");
return retVal;
}
}

.....

<bean id="aspectBean" class="com.chou.spring.domain.Interceptor"/>

<aop:config proxy-target-class="false">
<aop:aspect ref="aspectBean">
<!-- 定义切入点 -->
<aop:pointcut id="myAspect"
expression="execution(public * com.chou.spring.bean..*.domain(..))" />

<!-- 前置通知 -->
<aop:before pointcut-ref="myAspect" method="prepareDomain"/>

<!-- 后置通知 -->
<aop:after-returning pointcut-ref="myAspect" method="afterReturning"/>
<aop:after-throwing pointcut-ref="myAspect" method="afterThrowing"/>
<aop:after pointcut-ref="myAspect" method="afterDomain"/>

<!-- 环绕通知 -->
<aop:around method="around"
pointcut="execution(* com.chou.spring.bean..*.sayAround(..))"/>
</aop:aspect>
</aop:config>

Java代码

public interface MyBean {
public void domain();
}

public class MyBeanA{
public void domain() {
System.out.println("MyBeanA is executing...");
}

public void sayAround(String param) {
System.out.println("around param:" + param);
}
}

public class MyBeanB implements MyBean{
public void domain() {
System.out.println("MyBeanB is executing...");
//throw new RuntimeException("This is a RuntimeException");
}
}

//main方法....
String[] configs = new String[] {"applicationContext-aop.xml"};
ApplicationContext cxt = new ClassPathXmlApplicationContext(configs);
//如果Bean有interface那么就用JDK的Proxy.newProxyInstance得到代理对象进行aop
MyBean b = (MyBean)cxt.getBean("beanB");
b.domain();
//如果Bean没有实现任何interface那么就用CGLIB得到代理对象进行aop
MyBeanA a = cxt.getBean("beanA",MyBeanA.class);
a.domain();
a.sayAround("jjjjjjjjjjjjjjjjjjj");

五、Advisor 表示只有一个通知和一个切入点的切面

<aop:advisor pointcut="切入点表达式" pointcut-ref="切入点Bean引用"
advice-ref="通知API实现引用"/>

<bean id="beforeAdvice" class="cn.javass.spring.chapter6.aop.BeforeAdviceImpl"/>
<aop:advisor pointcut="execution(* cn.javass..*.sayAdvisorBefore(..))"
advice-ref="beforeAdvice"/>

除了在进行事务控制的情况下，其他情况一般不推荐使用该方式，该方式属于侵入式设计，必须实现通知API

Xml代码

<!-- 事务管理器配置,单数据源事务 -->
<bean id="transactionManager"
class="org.springframework.orm.hibernate3.HibernateTransactionManager">
<property name="sessionFactory" ref="sessionFactory" />
</bean>

<aop:config>
<aop:advisor pointcut="execution(* com.spring.test.service..*.*(..))"
advice-ref="txAdvice" />
</aop:config>

<tx:advice id="txAdvice" transaction-manager="transactionManager">
<tx:attributes>
<tx:method name="get*" read-only="true" />
<tx:method name="find*" read-only="true" />
<tx:method name="list*" read-only="true" />
<tx:method name="save*" />
<tx:method name="update*" />
<tx:method name="delete*" />
</tx:attributes>
</tx:advice>