java中的注解

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

import cn.itcast.day1.EnumTest;

@Retention(RetentionPolicy.RUNTIME)
@Target({ElementType.METHOD,ElementType.TYPE})
public @interface ItcastAnnotation {
String color() default "blue";
String value();
int[] arrayAttr() default {3,4,4};
EnumTest.TrafficLamp lamp() default EnumTest.TrafficLamp.RED;
MetaAnnotation annotationAttr() default @MetaAnnotation("lhm");
Class classAttr() default String.class;
}

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import java.lang.reflect.Method;

//import javax.jws.soap.InitParam;

@ItcastAnnotation(classAttr=Integer.class,annotationAttr=@MetaAnnotation("flx"),color="red",value="abc",arrayAttr=1)
public class AnnotationTest {

/**
* @param args
*/
@SuppressWarnings("deprecation")
@ItcastAnnotation("xyz")
public static void main(String[] args) throws Exception{
// TODO Auto-generated method stub
System.runFinalizersOnExit(true);
if(AnnotationTest.class.isAnnotationPresent(ItcastAnnotation.class)){
ItcastAnnotation annotation = (ItcastAnnotation)AnnotationTest.class.getAnnotation(ItcastAnnotation.class);
System.out.println(annotation.color());
System.out.println(annotation.value());
System.out.println(annotation.arrayAttr()/*.length*/);
System.out.println(annotation.lamp().nextLamp().name());
System.out.println(annotation.annotationAttr().value());
System.out.println(annotation.classAttr());
}

Method mainMethod = AnnotationTest.class.getMethod("main", String[].class);
ItcastAnnotation annotation2 = (ItcastAnnotation)mainMethod.getAnnotation(ItcastAnnotation.class);
System.out.println(annotation2.value());
}

@Deprecated
public static void sayHello(){
System.out.println("hi,���Dz���");
}
}

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public @interface MetaAnnotation {
String value();
}