注解处理器

demo：

/1：*** 定义注解*/
@Target(ElementType.FIELD)
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface FruitProvider {
 /**供应商编号*/
public int id() default -1;
/*** 供应商名称*/
 public String name() default ""；
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 /** * 供应商地址*/
 public String address() default "";
}
//2：注解使用
public class Apple {
 @FruitProvider(id = 1, name = "陕西红富士集团", address = "陕西省西安市延安路")
 private String appleProvider;
 public void setAppleProvider(String appleProvider) {
 this.appleProvider = appleProvider;
 }
 public String getAppleProvider() {
 return appleProvider;
 }
}
/3：*********** 注解处理器 ***************/
public class FruitInfoUtil {
 public static void getFruitInfo(Class<?> clazz) {
 String strFruitProvicer = "供应商信息：";
 Field[] fields = clazz.getDeclaredFields();//通过反射获取处理注解
 for (Field field : fields) {
 if (field.isAnnotationPresent(FruitProvider.class)) {
 FruitProvider fruitProvider = (FruitProvider) field.getAnnotation(FruitProvider.class);
//注解信息的处理地方 
strFruitProvicer = " 供应商编号：" + fruitProvider.id() + " 供应商名称："
 + fruitProvider.name() + " 供应商地址："+ fruitProvider.address();
 System.out.println(strFruitProvicer);
 }
 }
 }
}
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public class FruitRun {
 public static void main(String[] args) {
 FruitInfoUtil.getFruitInfo(Apple.class);
/***********输出结果***************/
// 供应商编号：1 供应商名称：陕西红富士集团 供应商地址：陕西省西安市延
 }
}