关于java注解比较详细的例子

package com.annotation; import java.lang.annotation.Annotation; /** * 主意当不想value=11定义时，其他参数必须有default，这样value才能这样定义@MyAnnotation(11) */ @MyAnnotation(value=11,name="bb",names={"cc","dd"},getMyEnum=MyEnum.One,getMyBo=Class.class) public class UseAnnotation { //省略变量名称有且只能是value @MyAnnotation(13) private int inttest; @MyAnnotation(value=11,name="wodenianga") private String nnd; @MyAnnotation(value=12,name="aa",names={"ff","ee"},getMyEnum=MyEnum.Three,getMyBo=MyBo.class) public static void main(String[] args) throws Exception{ System.out.println("class annotation print------------"); if(UseAnnotation.class.isAnnotationPresent(MyAnnotation.class)){ MyAnnotation ann = UseAnnotation.class.getAnnotation(MyAnnotation.class); System.out.println(ann.name()); System.out.println(ann.names().length); System.out.println(ann.value()); System.out.println(ann.getMyEnum()); System.out.println(ann.getMyBo().getName()); } System.out.println("method annotation print-----------------"); if(UseAnnotation.class.getDeclaredMethod("main", String[].class).isAnnotationPresent(MyAnnotation.class)){ MyAnnotation ann = UseAnnotation.class.getDeclaredMethod("main", String[].class).getAnnotation(MyAnnotation.class); System.out.println(ann.name()); System.out.println(ann.names().length); System.out.println(ann.value()); System.out.println(ann.getMyEnum()); System.out.println(ann.getMyBo().getName()); } System.out.println("fild annotation print-----------------"); if(UseAnnotation.class.getDeclaredField("nnd").isAnnotationPresent(MyAnnotation.class)){ MyAnnotation ann = UseAnnotation.class.getDeclaredField("nnd").getAnnotation(MyAnnotation.class); System.out.println(ann.name()); System.out.println(ann.names().length); System.out.println(ann.value()); System.out.println(ann.getMyEnum()); System.out.println(ann.getMyBo().getName()); } getStr("nid",new String[]{"gf","dfd"}); } public static String getStr(@MyAnnotation(value=23,name="zhldahd") String test,@MyAnnotation(value=44,names={"sssssssssss","wodema"},name="gpisjo") String[] nida) throws Exception{ Annotation[][] ann = UseAnnotation.class.getDeclaredMethod("getStr", new Class[]{String.class,String[].class}).getParameterAnnotations(); System.out.println(((MyAnnotation)ann[0][0]).name()); System.out.println(((MyAnnotation)ann[0][0]).names()[0]); System.out.println(((MyAnnotation)ann[1][0]).name()); System.out.println(((MyAnnotation)ann[1][0]).names()[0]); return test+"玩的才"; } }