Created
August 7, 2019 03:39
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Java 中注解可以添加在方法的参数上
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| public class Run { | |
| @Target(ElementType.PARAMETER) | |
| @Retention(RetentionPolicy.RUNTIME) | |
| static @interface QueryParam { | |
| String value(); | |
| } | |
| public void testAnnotation(@QueryParam("action") String action) { | |
| System.out.printf("action is %s\n", action); | |
| } | |
| public static void exec() throws NoSuchMethodException { | |
| Class<?> cls = Run.class; | |
| Method method = cls.getMethod("testAnnotation", String.class); | |
| Annotation[][] annotations = method.getParameterAnnotations(); | |
| for (int i = 0; i < annotations.length; i++) { | |
| Annotation[] annotations1 = annotations[i]; | |
| for (Annotation annotation: annotations1) { | |
| if (annotation instanceof QueryParam) { | |
| QueryParam param = (QueryParam) annotation; | |
| System.out.printf("annotation simple name is %s and value is %s\n", | |
| param.annotationType().getSimpleName(), | |
| param.value()); | |
| String action = param.value() + "======="; | |
| try { | |
| method.invoke(new Run(), action); | |
| } catch (IllegalAccessException | InvocationTargetException e) { | |
| e.printStackTrace(); | |
| } | |
| } | |
| } | |
| } | |
| } | |
| } |
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