Spring AOP Schema aop:config、tx:advice

本文内容纲要:

- Spring AOP Schema aop:config、tx:advice

- 一、 利用aop:config标签实现AOP

- 1. 第一种方法aop:config中配置aop:pointcut和aop:aspect

- 2. 第二种方法aop:config中配置aop:pointcut和aop:advisor

- 二、 AOP中加入事务,引入tx:advice

Spring AOP Schema aop:config、tx:advice

一、 利用aop:config标签实现AOP

首先看个例子,如下

接口代码:

package com.lei.demo.aop.schema;

public interface IHello {

public void sayHello();

}

接口实现:

package com.lei.demo.aop.schema;

public class HelloService implements IHello {

public void sayHello() {

System.out.println("-----Hello World!-----");

}

}

接下来我们要实现AOP,即调用sayHello方法时切入通知。

1. 第一种方法aop:config中配置aop:pointcut和aop:aspect

定义一个切面支持类HelloAspect.java

package com.lei.demo.aop.schema;

/*

* 切面支持类

*/

public class HelloAspect {

//前置通知

public void beforeAdvice() {

System.out.println("===========before advice");

}

//后置最终通知

public void afterFinallyAdvice() {

System.out.println("===========after finally advice");

}

}

Xml配置:Spring-AOP-Schema.xml

<?xml version="1.0" encoding="UTF-8"?>

<beans xmlns="http://www.springframework.org/schema/beans"

xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

xmlns:aop="http://www.springframework.org/schema/aop"

xsi:schemaLocation="

http://www.springframework.org/schema/beans

http://www.springframework.org/schema/beans/spring-beans-3.2.xsd

http://www.springframework.org/schema/aop

http://www.springframework.org/schema/aop/spring-aop-3.2.xsd">

<!-- 目标类 -->

<bean id="helloService" class="com.lei.demo.aop.schema.HelloService" />

<bean id="helloAspect" class="com.lei.demo.aop.schema.HelloAspect" />

<!-- 配置切面 -->

<!-- aop:advisor,是有顺序的,必须放在aop:pointcut之后 -->

<aop:config>

<aop:pointcut id="helloPointcut" expression="execution(* com.lei.demo.aop.schema..*.*(..))" />

<aop:aspect ref="helloAspect">

<!—以下使用了两种方法定义切入点 pointcut-ref和pointcut-->

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

<aop:after pointcut="execution(* com.lei.demo.aop.schema..*.*(..))" method="afterFinallyAdvice" />

</aop:aspect>

</aop:config>

</beans>

以上配置中method=*"beforeAdvice"**、method="afterFinallyAdvice"*对应helloAspect中的方法

测试,App.java

package com.lei.demo.aop.schema;

import org.springframework.context.ApplicationContext;

import org.springframework.context.support.ClassPathXmlApplicationContext;

public class App {

private static ApplicationContext ctx;

public static void main(String[] args) {

ctx = new ClassPathXmlApplicationContext("Spring-AOP-Schema.xml");

IHello helloService = ctx.getBean("helloService",IHello.class);

helloService.sayHello();

}

}

运行App.java,结果如下:

===========before advice

-----Hello World!-----

===========after finally advice

2. 第二种方法aop:config中配置aop:pointcut和aop:advisor

实现org.aopalliance.intercept.MethodInvocation接口,

HelloAroundAdvice.java如下:

package com.lei.demo.aop.schema;

import java.lang.reflect.Method;

import org.aopalliance.intercept.MethodInterceptor;

import org.aopalliance.intercept.MethodInvocation;

public class HelloAroundAdvice implements MethodInterceptor {

public Object invoke(MethodInvocation arg0) throws Throwable {

System.out.println("++++++before advice");

arg0.proceed();

System.out.println("++++++after advice");

return null;

}

}

Xml配置:Spring-AOP-Schema.xml

<?xml version="1.0" encoding="UTF-8"?>

<beans xmlns="http://www.springframework.org/schema/beans"

xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

xmlns:aop="http://www.springframework.org/schema/aop"

xsi:schemaLocation="

http://www.springframework.org/schema/beans

http://www.springframework.org/schema/beans/spring-beans-3.2.xsd

http://www.springframework.org/schema/aop

http://www.springframework.org/schema/aop/spring-aop-3.2.xsd">

<!-- 目标类 -->

<bean id="helloService" class="com.lei.demo.aop.schema.HelloService" />

<bean id="helloAspect" class="com.lei.demo.aop.schema.HelloAspect" />

<bean id="helloArroundAdvice" class="com.lei.demo.aop.schema.HelloAroundAdvice" />

<!-- 配置切面 -->

<aop:config>

<aop:pointcut id="helloPointcut" expression="execution(* com.lei.demo.aop.schema..*.*(..))" />

<aop:advisor advice-ref="helloArroundAdvice" pointcut-ref="helloPointcut"/>

</aop:config>

</beans>

仍然运行App.java,结果如下:

++++++before advice

-----Hello World!-----

++++++after advice

二、 AOP中加入事务,引入tx:advice

集成Hibernate时,需要引入事务,以下配置引用Spring 4.0.3和Hibernate 4.3.5

Spring-hibernate.xml如下:

<?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:tx="http://www.springframework.org/schema/tx"

xmlns:aop="http://www.springframework.org/schema/aop"

xsi:schemaLocation="

http://www.springframework.org/schema/beans

http://www.springframework.org/schema/beans/spring-beans-4.0.xsd

http://www.springframework.org/schema/context

http://www.springframework.org/schema/context/spring-context-4.0.xsd

http://www.springframework.org/schema/aop

http://www.springframework.org/schema/aop/spring-aop-4.0.xsd

http://www.springframework.org/schema/tx

http://www.springframework.org/schema/tx/spring-tx-4.0.xsd

">

<!-- Hibernate4 -->

<!-- 加载资源文件 其中包含变量信息,必须在Spring配置文件的最前面加载,即第一个加载-->

<context:property-placeholder location="classpath:persistence-mysql.properties" />

<bean id="sessionFactory"

class="org.springframework.orm.hibernate4.LocalSessionFactoryBean">

<property name="dataSource" ref="dataSource" />

<property name="packagesToScan">

<list>

<!-- 可以加多个包 -->

<value>com.lei.demo.entity</value>

</list>

</property>

<property name="hibernateProperties">

<props>

<prop key="hibernate.hbm2ddl.auto">${hibernate.hbm2ddl.auto}</prop>

<prop key="hibernate.dialect">${hibernate.dialect}</prop>

<prop key="hibernate.show_sql">${hibernate.show_sql}</prop>

</props>

</property>

</bean>

<!-- 数据库映射 -->

<bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">

<property name="driverClassName" value="${jdbc.driverClassName}" />

<property name="url" value="${jdbc.url}" />

<property name="username" value="${jdbc.user}" />

<property name="password" value="${jdbc.pass}" />

</bean>

<!-- 配置Hibernate事务管理器 -->

<bean id="transactionManager"

class="org.springframework.orm.hibernate4.HibernateTransactionManager">

<property name="sessionFactory" ref="sessionFactory" />

</bean>

<!-- 配置事务异常封装 -->

<bean id="persistenceExceptionTranslationPostProcessor"

class="org.springframework.dao.annotation.PersistenceExceptionTranslationPostProcessor" />

<!-- 声明式容器事务管理 ,transaction-manager指定事务管理器为transactionManager-->

<tx:advice id="txAdvice" transaction-manager="transactionManager">

<tx:attributes>

<tx:method name="add*" propagation="REQUIRED" />

<tx:method name="get*" propagation="REQUIRED" />

<tx:method name="*" read-only="true" />

</tx:attributes>

</tx:advice>

<aop:config expose-proxy="true">

<!-- 只对业务逻辑层实施事务 -->

<aop:pointcut id="txPointcut" expression="execution(* com.lei.demo.service..*.*(..))" />

<!-- Advisor定义,切入点和通知分别为txPointcut、txAdvice -->

<aop:advisor pointcut-ref="txPointcut" advice-ref="txAdvice"/>

</aop:config>

</beans>

重点看一下tx:advice的配置

<tx:advice id="txAdvice" transaction-manager="transactionManager">

<tx:attributes>

<tx:method name="add*" propagation="REQUIRED" />

<tx:method name="get*" propagation="REQUIRED" />

<tx:method name="*" read-only="true" />

</tx:attributes>

</tx:advice>

意思是说,这个事务advice的管理者为transactionManager,而这个advice中规定了匹配add*get*方法的传输方式为required,也就是说没有sessionFactory的时候会自动建立,有的时候就不会建立了。当然这只是规定了一个advice,你还需要指定一个aop:pointcut去引用它,例如下边的aop:config配置节。这样,这个advice就被织入到txPointcut这个pointcut上了。

本文内容总结:Spring AOP Schema aop:config、tx:advice,一、 利用aop:config标签实现AOP,1. 第一种方法aop:config中配置aop:pointcut和aop:aspect,2. 第二种方法aop:config中配置aop:pointcut和aop:advisor,二、 AOP中加入事务,引入tx:advice,

原文链接:https://www.cnblogs.com/leiOOlei/p/3709607.html

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