java注解
下图转自:http://www.cnblogs.com/peida/archive/2013/04/26/3038503.html
下面实现一个自定义注解:
转自:http://www.cnblogs.com/whoislcj/p/5671622.html
@Documented @Retention(RetentionPolicy.RUNTIME) @Target(ElementType.METHOD) public @interface ReqType { enum ReqTypeEnum { GET, POST,DELETE,PUT } ReqTypeEnum reqType() default ReqTypeEnum.GET; }
@Documented @Target(ElementType.METHOD) @Retention(RetentionPolicy.RUNTIME) public @interface ReqUrl { String value() default ""; }
@Documented @Target(ElementType.PARAMETER) @Retention(RetentionPolicy.RUNTIME) public @interface ReqParam { String value() default ""; }
public interface IReqService { @ReqType(reqType = ReqType.ReqTypeEnum.POST) @ReqUrl("www.baidu.com") String login(@ReqParam("userId") String userId, @ReqParam("pwd") String pwd); }
public class Test { public static void main(String[] args) { IReqService service = create(ReqServiceImpl.class); String result = service.login("bai", "123456"); System.out.println(result); } private static <T> T create(final Class<T> service) { return (T) Proxy.newProxyInstance( service.getClassLoader(), new Class<?>[]{service}, new InvocationHandler() { @Override public Object invoke(Object proxy, Method method, Object[] args) throws Throwable { ReqType reqType = method.getAnnotation(ReqType.class); ReqUrl reqUrl = method.getAnnotation(ReqUrl.class); System.out.println("reqType:" + reqType.reqType()); System.out.println("reqUrl:" + reqUrl.value()); Type[] parameterTypes = method.getGenericParameterTypes(); Annotation[][] parameterAnnotations = method.getParameterAnnotations(); for (int i = 0; i < parameterAnnotations.length; i++) { Annotation[] parameterAnnotation = parameterAnnotations[i]; if (parameterAnnotation != null) { ReqParam reqParam = (ReqParam)parameterAnnotation[0]; System.out.println("reqParam->" + reqParam.value() + "==" + args[i]); } } //下面就可以执行相应的网络请求获取结果 返回结果 String result = "success";//这里模拟一个结果 return result; } } ); } }