Spring中基于AOP的XML架构

以下内容引用自http://wiki.jikexueyuan.com/project/spring/aop-with-spring-framenwork/xml-schema-based-aop-with-spring.html：

为了使用aop命名空间标签，需要导入spring-aop架构，如下所示：

<?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.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd"> 
</beans>

还需要增加而外的jar包用于支持AspectJ：

<!-- aspectjrt.jar -->
<!-- https://mvnrepository.com/artifact/org.aspectj/aspectjrt -->
<dependency>
<groupId>org.aspectj</groupId>
<artifactId>aspectjrt</artifactId>
<version>1.8.10</version>
</dependency>

<!-- aspectjweaver.jar -->
<!-- https://mvnrepository.com/artifact/org.aspectj/aspectjweaver -->
<dependency>
<groupId>org.aspectj</groupId>
<artifactId>aspectjweaver</artifactId>
<version>1.8.10</version>
</dependency>

集成步骤：

1、声明一个aspect（方面）

一个aspect是使用<aop:aspect>元素声明的，并使用ref属性引用bean，如下所示：

<aop:config>
<aop:aspect id="myAspect" ref="aBean">
...
</aop:aspect>
</aop:config>

<bean id="aBean" class="...">
...
</bean>

这个“aBean”将被配置和依赖注入就像其他Spring bean一样。

2、声明一个pointcut（切入点）

切入点有助于确定用不同建议执行的关联点（即方法）。在使用基于XML Schema的配置时，切入点将定义如下：

<aop:config>
<aop:aspect id="myAspect" ref="aBean">
　　<aop:pointcut id="businessService" expression="execution(* com.xyz.myapp.service.*.*(..))"/>
　　...
</aop:aspect>
</aop:config>
<bean id="aBean" class="...">
　　...
</bean>

以下示例定义了一个名为“businessService”的切入点，该切入点将匹配在com.tutorialspoint包中的Student类中可用的getName()方法：

<aop:config>
<aop:aspect id="myAspect" ref="aBean">
　　<aop:pointcut id="businessService" expression="execution(*com.tutorialspoint.Student.getName(..))"/>
　　...
</aop:aspect>
</aop:config>

<bean id="aBean" class="...">
...
</bean>

提示：

①类似：“execution(*com.tutorialspoint.Student.getName(..))”这样的语法叫做AspectJ切入点语法，参考：http://www.cnblogs.com/EasonJim/p/6901806.html

②官方文档关于AspectJ的介绍：https://docs.spring.io/spring/docs/current/spring-framework-reference/html/aop.html#aop-ataspectj

3、声明建议（通知类型）

可以使用<aop：{ADVICE NAME}>五个建议中的任何一个元素在<aop：aspect>内声明，如下所示：

<aop:config>
<aop:aspect id="myAspect" ref="aBean">
<aop:pointcut id="businessService" expression="execution(* com.xyz.myapp.service.*.*(..))"/>

<!-- a before advice definition -->
<aop:before pointcut-ref="businessService" method="doRequiredTask"/>

<!-- an after advice definition -->
<aop:after pointcut-ref="businessService" method="doRequiredTask"/>

<!-- an after-returning advice definition -->
<!--The doRequiredTask method must have parameter named retVal -->
<aop:after-returning pointcut-ref="businessService" returning="retVal" method="doRequiredTask"/>

<!-- an after-throwing advice definition -->
<!--The doRequiredTask method must have parameter named ex -->
<aop:after-throwing pointcut-ref="businessService" throwing="ex" method="doRequiredTask"/>

<!-- an around advice definition -->
<aop:around pointcut-ref="businessService" method="doRequiredTask"/>

　　　 ...
</aop:aspect>
</aop:config>

<bean id="aBean" class="...">
...
</bean>

可以对不同的建议使用相同的doRequiredTask或不同的方法。这些方法将被定义为方面模块的一部分。

至此集成完毕。

基于AOP的XML架构的示例：

pom.xml：

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion>

<groupId>com.jsoft.testspring</groupId>
<artifactId>testaopxml</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>

<name>testaopxml</name>
<url>http://maven.apache.org</url>

<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
</properties>

<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>3.8.1</version>
<scope>test</scope>
</dependency>

<!-- Spring Core -->
<!-- http://mvnrepository.com/artifact/org.springframework/spring-core -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-core</artifactId>
<version>4.1.4.RELEASE</version>
</dependency>

<!-- Spring Context -->
<!-- http://mvnrepository.com/artifact/org.springframework/spring-context -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>4.1.4.RELEASE</version>
</dependency>

<!-- String AOP -->
<!-- http://mvnrepository.com/artifact/org.springframework/spring-aop -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-aop</artifactId>
<version>4.1.4.RELEASE</version>
</dependency>

<!-- aspectjrt.jar -->
<!-- https://mvnrepository.com/artifact/org.aspectj/aspectjrt -->
<dependency>
<groupId>org.aspectj</groupId>
<artifactId>aspectjrt</artifactId>
<version>1.8.10</version>
</dependency>

<!-- aspectjweaver.jar -->
<!-- https://mvnrepository.com/artifact/org.aspectj/aspectjweaver -->
<dependency>
<groupId>org.aspectj</groupId>
<artifactId>aspectjweaver</artifactId>
<version>1.8.10</version>
</dependency>

</dependencies>
</project>

Logging.java：

package com.jsoft.testspring.testaopxml;

public class Logging {

public void beforeAdvice() {
System.out.println("Going to setup student profile.");
}

public void afterAdvice() {
System.out.println("Student profile has been setup.");
}

public void afterReturningAdvice(Object retVal) {
System.out.println("Returning:" + retVal.toString());
}

public void AfterThrowingAdvice(IllegalArgumentException ex) {
System.out.println("There has been an exception: " + ex.toString());
}
}

Student.java：

package com.jsoft.testspring.testaopxml;

public class Student {
private Integer age;
private String name;

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

public Integer getAge() {
System.out.println("Age : " + age);
return age;
}

public void setName(String name) {
this.name = name;
}

public String getName() {
System.out.println("Name : " + name);
return name;
}

public void printThrowException() {
System.out.println("Exception raised:");
throw new IllegalArgumentException();
}
}

beans.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.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd"> 
<aop:config>
<aop:aspect id="log" ref="logging">
<aop:pointcut id="selectAll" expression="execution(* com.jsoft..*.*(..))"/>
<aop:before pointcut-ref="selectAll" method="beforeAdvice"/>
<aop:after pointcut-ref="selectAll" method="afterAdvice"/>
<aop:after-returning pointcut-ref="selectAll" returning="retVal" method="afterReturningAdvice"/>
<aop:after-throwing pointcut-ref="selectAll" throwing="ex" method="AfterThrowingAdvice"/>
</aop:aspect>
</aop:config>

<bean id="student" class="com.jsoft.testspring.testaopxml.Student">
<property name="name"  value="Zara" />
<property name="age"  value="11"/>
</bean>

<bean id="logging" class="com.jsoft.testspring.testaopxml.Logging"/>

</beans>

App.java：

package com.jsoft.testspring.testaopxml;

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

/**
* Hello world!
*
*/
public class App
{
public static void main( String[] args )
{
ApplicationContext context = new ClassPathXmlApplicationContext("beans.xml");
Student student = (Student) context.getBean("student");
student.getName();
student.getAge();
student.printThrowException();
}
}

测试结果：



测试工程：https://github.com/easonjim/5_java_example/tree/master/springtest/test16/testaopxml