一个简单的Spring的AOP例子

Love The Way You Lie 2022-06-16 06:14 241阅读 0赞

[一个简单的Spring的AOP例子][Spring_AOP]

经过这段日子的学习和使用Spring,慢慢地体会到Spring的优妙之处，正在深入地吸收Spring的精华，呵呵。现在写的这个只是个简单AOP例子,包括前置通知，后置通知,环绕通知,和目标对象。写这个例子的主要目标只是想让想学AOP的能更快地入门，了解一下如何去配置AOP里面的东东。  
目标对象的接口:IStudent.java

1  ![ExpandedBlockStart.gif][]  /\*\*   
 2 ![InBlock.gif][] \*   
 3 ![ExpandedBlockEnd.gif][]  \*/    
  4  ![None.gif][]  package   com.dragon.study;  
  5  ![None.gif][]   
  6  ![ExpandedBlockStart.gif][]  /\*\*   
 7 ![InBlock.gif][] \*  @author  dragon  
 8 ![InBlock.gif][] \*  
 9 ![ExpandedBlockEnd.gif][]  \*/    
 10  ![ExpandedBlockStart.gif][]  public     interface   IStudent   \{  
11 ![InBlock.gif][]      
12 ![InBlock.gif][]     public   void  addStudent(String name);  
13 ![ExpandedBlockEnd.gif][]\}    
 14  ![None.gif][]

目标类:StudentImpl.java

1  ![ExpandedBlockStart.gif][]  /\*\*   
 2 ![InBlock.gif][] \*   
 3 ![ExpandedBlockEnd.gif][]  \*/    
  4  ![None.gif][]  package   com.dragon.study.Impl;  
  5  ![None.gif][]   
  6  ![None.gif][]  import   com.dragon.study.IStudent;  
  7  ![None.gif][]   
  8  ![ExpandedBlockStart.gif][]  /\*\*   
 9 ![InBlock.gif][] \*  @author  dragon  
10 ![InBlock.gif][] \*  
11 ![ExpandedBlockEnd.gif][]  \*/    
 12  ![ExpandedBlockStart.gif][]  public     class   StudentImpl   implements   IStudent  \{  
13 ![InBlock.gif][]   
14 ![ExpandedSubBlockStart.gif][]       public   void  addStudent(String name) \{  
15 ![InBlock.gif][]         System.out.println( " 欢迎  " \+ name \+ "  你加入Spring家庭! " );  
16 ![ExpandedSubBlockEnd.gif][]     \}   
17 ![ExpandedBlockEnd.gif][]\}    
 18  ![None.gif][]

前置通知:BeforeAdvice.java

1  ![ExpandedBlockStart.gif][]  /\*\*   
 2 ![InBlock.gif][] \*   
 3 ![ExpandedBlockEnd.gif][]  \*/    
  4  ![None.gif][]  package   com.dragon.Advice;  
  5  ![None.gif][]   
  6  ![None.gif][]  import   java.lang.reflect.Method;  
  7  ![None.gif][]   
  8  ![None.gif][]  import   org.springframework.aop.MethodBeforeAdvice;  
  9  ![None.gif][]   
 10  ![ExpandedBlockStart.gif][]  /\*\*   
11 ![InBlock.gif][] \*  @author  dragon  
12 ![InBlock.gif][] \*  
13 ![ExpandedBlockEnd.gif][]  \*/    
 14  ![ExpandedBlockStart.gif][]  public     class   BeforeAdvice   implements   MethodBeforeAdvice  \{  
15 ![InBlock.gif][]   
16 ![InBlock.gif][]       public   void  before(Method method,Object\[\] args, Object target)  
17 ![ExpandedSubBlockStart.gif][]                 throws  Throwable \{  
18 ![InBlock.gif][]            
19 ![InBlock.gif][]          System.out.println( " 这是BeforeAdvice类的before方法. " );  
20 ![InBlock.gif][]            
21 ![ExpandedSubBlockEnd.gif][]      \}   
22 ![ExpandedBlockEnd.gif][]\}    
 23  ![None.gif][]

后置通知:AfterAdvice.java

1 ![ExpandedBlockStart.gif][] /\*\*  
 2![InBlock.gif][] \*   
 3![ExpandedBlockEnd.gif][] \*/   
  4 ![None.gif][] package  com.dragon.Advice;  
  5 ![None.gif][]  
  6 ![None.gif][] import  java.lang.reflect.Method;  
  7 ![None.gif][]  
  8 ![None.gif][] import  org.springframework.aop.AfterReturningAdvice;  
  9 ![None.gif][]  
 10 ![ExpandedBlockStart.gif][] /\*\*  
11![InBlock.gif][] \* @author dragon  
12![InBlock.gif][] \*  
13![ExpandedBlockEnd.gif][] \*/   
 14 ![ExpandedBlockStart.gif][] public   class  AfterAdvice  implements  AfterReturningAdvice \{  
15![InBlock.gif][]      
16![InBlock.gif][]    public void afterReturning(Object returnValue ,Method method,  
17![ExpandedSubBlockStart.gif][]                   Object\[\] args,Object target) throws Throwable\{  
18![InBlock.gif][]        System.out.println("这是AfterAdvice类的afterReturning方法.");  
19![ExpandedSubBlockEnd.gif][]    \}  
20![InBlock.gif][]        
21![InBlock.gif][]  
22![ExpandedBlockEnd.gif][]\}   
 23 ![None.gif][]

环绕通知:CompareInterceptor.java

1 ![ExpandedBlockStart.gif][] /\*\*  
 2![InBlock.gif][] \*   
 3![ExpandedBlockEnd.gif][] \*/   
  4 ![None.gif][] package  com.dragon.Advice;  
  5 ![None.gif][]  
  6 ![None.gif][] import  org.aopalliance.intercept.MethodInterceptor;  
  7 ![None.gif][] import  org.aopalliance.intercept.MethodInvocation;  
  8 ![None.gif][]  
  9 ![None.gif][]  
 10 ![ExpandedBlockStart.gif][] /\*\*  
11![InBlock.gif][] \* @author dragon  
12![InBlock.gif][] \*  
13![ExpandedBlockEnd.gif][] \*/   
 14 ![ExpandedBlockStart.gif][] public   class  CompareInterceptor  implements  MethodInterceptor \{  
15![InBlock.gif][]  
16![ExpandedSubBlockStart.gif][]      public Object invoke(MethodInvocation invocation) throws Throwable\{  
17![InBlock.gif][]          Object result = null;  
18![InBlock.gif][]         String stu\_name = invocation.getArguments()\[0\].toString();  
19![ExpandedSubBlockStart.gif][]         if ( stu\_name.equals("dragon"))\{  
20![InBlock.gif][]             //如果学生是dragon时,执行目标方法,  
21![InBlock.gif][]              result= invocation.proceed();  
22![InBlock.gif][]                
23![ExpandedSubBlockStart.gif][]         \} else\{  
24![InBlock.gif][]             System.out.println("此学生是"\+stu\_name\+"而不是dragon,不批准其加入.");  
25![ExpandedSubBlockEnd.gif][]         \}  
26![InBlock.gif][]          
27![InBlock.gif][]          return result;  
28![ExpandedSubBlockEnd.gif][]      \}  
29![ExpandedBlockEnd.gif][]\}   
 30 ![None.gif][]

配置文件applicationContext.xml

1 ![None.gif][] <? xml version="1.0" encoding="UTF-8" ?>   
  2 ![None.gif][] <! DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN" "http://www.springframework.org/dtd/spring-beans.dtd" >   
  3 ![None.gif][]  
  4 ![None.gif][] < beans >   
  5 ![None.gif][]  
  6 ![None.gif][] < bean  id ="beforeAdvice"  class ="com.dragon.Advice.BeforeAdvice" ></ bean >   
  7 ![None.gif][] < bean  id ="afterAdvice"  class ="com.dragon.Advice.AfterAdvice" ></ bean >   
  8 ![None.gif][] < bean  id ="compareInterceptor"  class ="com.dragon.Advice.CompareInterceptor" ></ bean >   
  9 ![None.gif][] < bean  id ="studenttarget"  class ="com.dragon.study.Impl.StudentImpl" ></ bean >   
 10 ![None.gif][]  
 11 ![None.gif][] < bean  id ="student"  class ="org.springframework.aop.framework.ProxyFactoryBean" >   
 12 ![None.gif][]   < property  name ="proxyInterfaces" >   
 13 ![None.gif][]     < value > com.dragon.study.IStudent </ value >   
 14 ![None.gif][]   </ property >   
 15 ![None.gif][]   < property  name ="interceptorNames" >   
 16 ![None.gif][]     < list >   
 17 ![None.gif][]      < value > beforeAdvice </ value >   
 18 ![None.gif][]      < value > afterAdvice </ value >   
 19 ![None.gif][]     < value > compareInterceptor </ value >     
 20 ![None.gif][]     </ list >   
 21 ![None.gif][]   </ property >   
 22 ![None.gif][]   < property  name ="target" >   
 23 ![None.gif][]     < ref  bean ="studenttarget" />   
 24 ![None.gif][]   </ property >   
 25 ![None.gif][]  
 26 ![None.gif][] </ bean >   
 27 ![None.gif][]  
 28 ![None.gif][]  
 29 ![None.gif][]  
 30 ![None.gif][]  
 31 ![None.gif][] </ beans >

现在开始写测试类,Test.java

1 ![ExpandedBlockStart.gif][] /\*\*  
 2![InBlock.gif][] \*   
 3![ExpandedBlockEnd.gif][] \*/   
  4 ![None.gif][] package  com;  
  5 ![None.gif][]  
  6 ![None.gif][] import  org.springframework.context.ApplicationContext;  
  7 ![None.gif][] import  org.springframework.context.support.FileSystemXmlApplicationContext;  
  8 ![None.gif][]  
  9 ![None.gif][] import  com.dragon.study.IStudent;  
 10 ![None.gif][]  
 11 ![ExpandedBlockStart.gif][] /\*\*  
12![InBlock.gif][] \* @author dragon  
13![InBlock.gif][] \*  
14![ExpandedBlockEnd.gif][] \*/   
 15 ![ExpandedBlockStart.gif][] public   class  Test  \{  
16![InBlock.gif][]  
17![ExpandedSubBlockStart.gif][]    /\*\*  
18![InBlock.gif][]     \* @param args  
19![ExpandedSubBlockEnd.gif][]     \*/  
20![ExpandedSubBlockStart.gif][]    public static void main(String\[\] args) \{  
21![InBlock.gif][]        // TODO Auto-generated method stub  
22![InBlock.gif][]      ApplicationContext ctx =   
23![InBlock.gif][]          new FileSystemXmlApplicationContext("/com/dragon/applicationContext.xml");  
24![InBlock.gif][]        
25![InBlock.gif][]      IStudent person = (IStudent)ctx.getBean("student");  
26![InBlock.gif][]      person.addStudent("dragon");  
27![InBlock.gif][]        
28![InBlock.gif][]//      person.addStudent("javadragon");  
29![ExpandedSubBlockEnd.gif][]    \}  
30![InBlock.gif][]  
31![ExpandedBlockEnd.gif][]\}   
 32 ![None.gif][]

[Spring_AOP]: http://www.blogjava.net/javadragon/archive/2006/12/03/85115.html
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[ExpandedBlockEnd.gif]: /images/20220616/4d2376a958a24ee6b86dbb69f2531fc4.png
[None.gif]: /images/20220616/2f985908276c453598c76ac472ef2fbd.png
[ExpandedSubBlockStart.gif]: /images/20220616/e3d307b1c38a4252a9fec39f1987df68.png
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