Spring AOP基於XML的應用程式


從這篇文章開始,我們使用Spring-AOP框架編寫實際的AOP應用程式。在開始使用Spring-WS框架編寫第一個範例之前,必須確保已經按照Spring AOP安裝組態教學中的說明正確設定了Spring-AOP開發執行環境。

現在我們繼續來編寫一個簡單的基於控制台的Spring AOP應用程式,它用於演示AOP的概念。

先來看看要建立的專案的目錄結構 -

建立專案

開啟命令控制台,進入D:\MVN目錄並執行下面的mvn命令。

D:\MVN> mvn archetype:generate -DgroupId=com.yiibai -DartifactId=Student -DarchetypeArtifactId=maven-archetype-quickstart -DinteractiveMode=false

上面命令執行後,Maven將開始處理,並將建立完整的java應用程式專案結構。您可能會看到一堆下載的東西,但是不要驚慌,耐心等待下載和構建完成,如下所示 -

Downloaded: http://repo.maven.apache.org/maven2/org/apache/maven/archetypes/maven-archetype-quickstart/1.0/maven-archetype-quickstart-1.0.jar (5 KB at 7.7 KB/sec)
[INFO] ----------------------------------------------------------------------------
[INFO] Using following parameters for creating project from Old (1.x) Archetype: maven-archetype-quickstart:1.0
[INFO] ----------------------------------------------------------------------------
[INFO] Parameter: basedir, Value: D:\mvn
[INFO] Parameter: package, Value: com.yiibai
[INFO] Parameter: groupId, Value: com.yiibai
[INFO] Parameter: artifactId, Value: Student
[INFO] Parameter: packageName, Value: com.yiibai
[INFO] Parameter: version, Value: 1.0-SNAPSHOT
[INFO] project created from Old (1.x) Archetype in dir: D:\mvn\Student
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 09:20 min
[INFO] Finished at: 2017-04-12T03:05:53+08:00
[INFO] Final Memory: 14M/99M
[INFO] ------------------------------------------------------------------------

D:\mvn>

現在開啟C:\MVN目錄。您將看到一個名為student的java應用程式專案(在artifactId中指定)。更新POM.xml以包含Spring-AOP依賴關係。新增MainApp.javaStudent.javaLogging.java這幾個程式碼檔案。

檔案 - POM.xml 的內容如下 -

<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/maven-v4_0_0.xsd">
   <modelVersion>4.0.0</modelVersion>
   <groupId>com.yiibai</groupId>
   <artifactId>Student</artifactId>
   <packaging>jar</packaging>
   <version>1.0-SNAPSHOT</version>
   <name>Student</name>
   <url>http://maven.apache.org</url>
   <dependencies>
      <dependency>
         <groupId>junit</groupId>
         <artifactId>junit</artifactId>
         <version>3.8.1</version>
         <scope>test</scope>
      </dependency>
      <dependency>
         <groupId>org.springframework</groupId>
         <artifactId>spring-aop</artifactId>
         <version>4.1.0.RELEASE</version>
      </dependency>
      <dependency>
         <groupId>org.springframework</groupId>
         <artifactId>spring-context</artifactId>
         <version>4.1.4.RELEASE</version>
      </dependency>
      <dependency>
         <groupId>org.aspectj</groupId>
         <artifactId>aspectjweaver</artifactId>
         <version>1.6.8</version>
      </dependency>
   </dependencies>
</project>

檔案 - Logging.java 的內容如下 -

package com.yiibai;

public class Logging {

   /** 
    * This is the method which I would like to execute
    * before a selected method execution.
    */
   public void beforeAdvice(){
      System.out.println("Going to setup student profile.");
   }

   /** 
    * This is the method which I would like to execute
    * after a selected method execution.
    */
   public void afterAdvice(){
      System.out.println("Student profile has been setup.");
   }

   /** 
    * This is the method which I would like to execute
    * when any method returns.
    */
   public void afterReturningAdvice(Object retVal){
      System.out.println("Returning:" + retVal.toString() );
   }

   /**
    * This is the method which I would like to execute
    * if there is an exception raised.
    */
   public void AfterThrowingAdvice(IllegalArgumentException ex){
      System.out.println("There has been an exception: " + ex.toString());   
   }

}

檔案 - Student.java 的內容如下 -

package com.yiibai;

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();
   }
}

檔案 - MainApp.java 的內容如下 -

package com.yiibai;

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

public class MainApp {
   public static void main(String[] args) {
      ApplicationContext context = 
             new ClassPathXmlApplicationContext("Beans.xml");

      Student student = (Student) context.getBean("student");

      student.getName();
      student.getAge();

      student.printThrowException();
   }
}

src/main/resources檔案夾下新增組態檔案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-3.0.xsd 
    http://www.springframework.org/schema/aop 
    http://www.springframework.org/schema/aop/spring-aop-3.0.xsd ">

   <aop:config>
      <aop:aspect id="log" ref="logging">
         <aop:pointcut id="selectAll" 
         expression="execution(* com.yiibai.*.*(..))"/>
         <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>

   <!-- Definition for student bean -->
   <bean id="student" class="com.yiibai.Student">
      <property name="name"  value="Maxsu" />
      <property name="age"  value="21"/>      
   </bean>

   <!-- Definition for logging aspect -->
   <bean id="logging" class="com.yiibai.Logging"/> 

</beans>

開啟命令控制台,進入D:\MVN目錄並執行下面的mvn命令。

D:\MVN>Student> mvn package

Maven將開始處理並下載所需的庫。

Downloading: http://repo.maven.apache.org/maven2/commons-lang/commons-lang/2.1/commons-lang-2.1.jar
Downloading: http://repo.maven.apache.org/maven2/org/codehaus/plexus/plexus-utils/3.0/plexus-utils-3.0.jar
Downloaded: http://repo.maven.apache.org/maven2/org/apache/maven/maven-archiver/2.5/maven-archiver-2.5.jar (22 KB at 25.9 KB/sec)
Downloaded: http://repo.maven.apache.org/maven2/org/codehaus/plexus/plexus-io/2.0.2/plexus-io-2.0.2.jar (57 KB at 54.3 KB/sec)
Downloaded: http://repo.maven.apache.org/maven2/commons-lang/commons-lang/2.1/commons-lang-2.1.jar (203 KB at 188.7 KB/sec)
Downloaded: http://repo.maven.apache.org/maven2/org/codehaus/plexus/plexus-utils/3.0/plexus-utils-3.0.jar (221 KB at 145.8 KB/sec)
Downloaded: http://repo.maven.apache.org/maven2/org/codehaus/plexus/plexus-archiver/2.1/plexus-archiver-2.1.jar (181 KB at 100.8 KB/sec)
[INFO] Building jar: D:\mvn\Student\target\Student-1.0-SNAPSHOT.jar
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 43.164 s
[INFO] Finished at: 2017-04-12T05:11:44+08:00
[INFO] Final Memory: 19M/158M
[INFO] ------------------------------------------------------------------------

D:\mvn\Student>

在Eclipse中匯入專案

開啟Eclipse IDE,匯入專案目錄。

選擇檔案>匯入>選項
選擇Maven專案選項。點選下一步按鈕。
選擇專案位置,其中使用Maven建立Student專案。
單擊完成按鈕。

執行專案

完成建立原始碼和組態檔案後,執行應用程式。 右鍵單擊應用程式中的MainApp.java,並使用執行方式作為Java應用程式命令。 如果您的應用程式沒有問題,將列印以下訊息:

四月 12, 2017 5:19:04 上午 org.springframework.context.support.ClassPathXmlApplicationContext prepareRefresh
資訊: Refreshing org[email protected]300ffa5d: startup date [Wed Apr 12 05:19:04 CST 2017]; root of context hierarchy
四月 12, 2017 5:19:04 上午 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
資訊: Loading XML bean definitions from class path resource [Beans.xml]
Going to setup student profile.
Exception in thread "main" Name : Maxsu
Student profile has been setup.
Returning:Maxsu
Going to setup student profile.
Age : 21
Student profile has been setup.
Returning:21
Going to setup student profile.
Exception raised
Student profile has been setup.
There has been an exception: java.lang.IllegalArgumentException
java.lang.IllegalArgumentException
    at com.yiibai.Student.printThrowException(Student.java:25)
    at com.yiibai.Student$$FastClassBySpringCGLIB$$e9280b4b.invoke(<generated>)
    at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204)
    at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:717)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157)
    at org.springframework.aop.framework.adapter.MethodBeforeAdviceInterceptor.invoke(MethodBeforeAdviceInterceptor.java:52)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.aop.aspectj.AspectJAfterAdvice.invoke(AspectJAfterAdvice.java:43)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.aop.framework.adapter.AfterReturningAdviceInterceptor.invoke(AfterReturningAdviceInterceptor.java:52)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.aop.aspectj.AspectJAfterThrowingAdvice.invoke(AspectJAfterThrowingAdvice.java:58)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:92)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:653)
    at com.yiibai.Student$$EnhancerBySpringCGLIB$$92ccc3c2.printThrowException(<generated>)
    at com.yiibai.MainApp.main(MainApp.java:16)