目的：为studentAdditionalDetails中添加Student的showDetails（）和ExtraShowDetails（）两个方法
spring 中AOP能够为现有的方法添加额外的功能，AOP也能为Spring Bean添加新方法
<aop:declare-parents
types-matching="之前原始的类/接口"
implement-interface="想要添加的功能的接口"
defalut-impl="新功能的默认的实现"
/>
或者：
<aop:declare-parents types-matching="之前原始的类/接口" implement-interface="想要添加的功能的接口" delegate-ref="新功能的默认的实现" />
配置文件：
1 <?xml version="1.0" encoding="UTF-8"?> 2 3 <beans xmlns="http://www.springframework.org/schema/beans" 4 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 5 xmlns:aop="http://www.springframework.org/schema/aop" 6 xmlns:tx="http://www.springframework.org/schema/tx" 7 xmlns:p="http://www.springframework.org/schema/p" 8 xsi:schemaLocation=" 9 http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd 10 http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.5.xsd 11 http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.5.xsd"> 12 13 14 15 16 <!-- 为StudentAdditionalDetails或者StudentAdditionalDetailsImpl添加student里面的方法 --> 17 <bean id="student" class="imple.StudentImpl"> 18 <property name="studentNo" value="1001" /> 19 <property name="studentName" value="John Peter" /> 20 </bean> 21 22 <bean id="studentAdditionalDetailsImpl" class="imple.StudentAdditionalDetailsImpl"> 23 <property name="city" value="Newyork" /> 24 <property name="country" value="America" /> 25 </bean> 26 27 <aop:config> 28 <aop:aspect> 29 <!-- types-matching="imple.StudentAdditionalDetailsImpl+" 改成下面的方式 实现的效果相同 30 说明：types-matching既可以是实现类也可以是接口 31 --> 32 <aop:declare-parents types-matching="inter.StudentAdditionalDetails+" 33 implement-interface="inter.Student" 34 delegate-ref="student" /> 35 </aop:aspect> 36 </aop:config> 37 38 39 </beans>
或者：
<?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" xmlns:tx="http://www.springframework.org/schema/tx" xmlns:p="http://www.springframework.org/schema/p" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.5.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.5.xsd"> <!-- 为StudentAdditionalDetails或者StudentAdditionalDetailsImpl添加student里面的方法 --> <bean id="student" class="imple.StudentImpl"> <property name="studentNo" value="1001" /> <property name="studentName" value="John Peter" /> </bean> <bean id="studentAdditionalDetails" class="imple.StudentAdditionalDetailsImpl"> <property name="city" value="Newyork" /> <property name="country" value="America" /> </bean> <aop:config> <aop:aspect> <!-- types-matching="imple.StudentAdditionalDetailsImpl+" 改成下面的方式 实现的效果相同 说明：types-matching既可以是实现类也可以是接口 --> <aop:declare-parents types-matching="inter.StudentAdditionalDetails+" implement-interface="inter.Student" default-impl="imple.StudentImpl" /> </aop:aspect> </aop:config> </beans>
注意：若采用
default-impl="imple.StudentImpl"
输出结果：不知道为何没有取到值？
1 StudentImpl showDetails studentNo :0
2 StudentImpl showDetails studentName :null
3 StudentImpl ExtraShowDetails studentNo :0
4 StudentImpl ExtraShowDetails studentName :null
5 StudentAdditionalDetailsImpl showAdditionalDetails() city:Newyork
6 StudentAdditionalDetailsImpl showAdditionalDetails() country:America
接口：
1 package inter; 2 3 public interface StudentAdditionalDetails { 4 public void showAdditionalDetails(); 5 }
1 package inter; 2 3 public interface Student { 4 public void showDetails(); 5 public void ExtraShowDetails(); 6 }
实现方法：
package imple; import inter.StudentAdditionalDetails; public class StudentAdditionalDetailsImpl implements StudentAdditionalDetails { private String city; private String country; public String getCity() { return city; } public void setCity(String city) { this.city = city; } public String getCountry() { return country; } public void setCountry(String country) { this.country = country; } public void showAdditionalDetails(){ System.out.println("StudentAdditionalDetailsImpl showAdditionalDetails() city:"+this.city); System.out.println("StudentAdditionalDetailsImpl showAdditionalDetails() country:"+this.country); } }
1 package imple; 2 3 import inter.Student; 4 5 public class StudentImpl implements Student { 6 private int studentNo; 7 private String studentName; 8 9 public int getStudentNo() { 10 return studentNo; 11 } 12 public void setStudentNo(int studentNo) { 13 this.studentNo = studentNo; 14 } 15 public String getStudentName() { 16 return studentName; 17 } 18 public void setStudentName(String studentName) { 19 this.studentName = studentName; 20 } 21 22 public void showDetails(){ 23 System.out.println("StudentImpl showDetails studentNo :"+this.studentNo); 24 System.out.println("StudentImpl showDetails studentName :"+this.studentName); 25 } 26 public void ExtraShowDetails() { 27 System.out.println("StudentImpl ExtraShowDetails studentNo :"+this.studentNo); 28 System.out.println("StudentImpl ExtraShowDetails studentName :"+this.studentName); 29 } 30 }
测试方法：
/*
* 基于xml 切面引入性能（为已经实现的类添加新的方法）
* Aop 常见的作用是为现有的方法添加新的功能，该测试方法可以通过Aop为Spring Bean添加新方法
*/
1 @Test 2 public void test9(){ 3 StudentAdditionalDetails studentAdditionalDetails = (StudentAdditionalDetails) ctx.getBean("studentAdditionalDetailsImpl"); 4 ((Student) studentAdditionalDetails).showDetails(); 5 ((Student) studentAdditionalDetails).ExtraShowDetails(); 6 studentAdditionalDetails.showAdditionalDetails(); 7 }
输出结果：
1 StudentImpl showDetails studentNo :1001 2 StudentImpl showDetails studentName :John Peter 3 StudentImpl ExtraShowDetails studentNo :1001 4 StudentImpl ExtraShowDetails studentName :John Peter 5 StudentAdditionalDetailsImpl showAdditionalDetails() city:Newyork 6 StudentAdditionalDetailsImpl showAdditionalDetails() country:America
--------------------------------------------------------以下基于注解实现-----------------------------------------------------------------------------
@DeclareParents( value=" AspectJ语法类型表达式", defaultImpl=引入接口的默认实现类) private Interface interface;