1、对于其概念和定义就不说了，直接看一下代码。
2、
Description.java
package com.lixx.annotation;
import java.lang.annotation.Documented;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface Description {
String value();
}
Name.javapackage com.lixx.annotation;
import java.lang.annotation.Documented;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
@Target(ElementType.METHOD)
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface Name {
String originate();
String community();
}
JavaEyer.javapackage com.lixx.annotation;
@Description(value="javaeye,做最棒的软件开发交流社区")
public class JavaEyer {
private String name;
@Name(originate="创始人:robbin",community="javaEye")
public String getName() {
return name;
}
@Name(originate="创始人：江南白衣",community="springside")
public void setName(String name) {
this.name = name;
}
}
TestAnnotation.javapackage com.lixx.annotation;
import java.lang.reflect.Method;
import java.util.HashSet;
import java.util.Set;
public class TestAnnotation {
public static void main(String[] args) throws ClassNotFoundException{
ClassNotFoundException ex ;
String CLASS_NAME = "com.lixx.annotation.JavaEyer";
try {
Class test = Class.forName(CLASS_NAME);
Method[] method = test.getMethods();
boolean flag = test.isAnnotationPresent(Description.class);
if(flag){
Description des = (Description)test.getAnnotation(Description.class);
System.out.println("描述为："+des.value());
}
/**
* 将javaeyer类中所有用到@Name的全部方法保存到set集合中去
*/
Set<Method> set = new HashSet<Method>();
for(Method methd : method){
boolean otherFlag = methd.isAnnotationPresent(Name.class);
if(otherFlag){
set.add(methd);
}
}
for(Method m : set){
Name name = m.getAnnotation(Name.class);
System.out.println(name.originate()+" "+"创建的社区："+name.community());
}
return ;
} catch (ClassNotFoundException e) {
ex = e;
}
if(null != ex){
throw ex;
}
}
}
可以试着运行下....