如何是用annotation 介绍

package com.annotation;

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

@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
public @interface MyAnnotation {
	String myvalue() default "Hi";
}

package com.annotation;

@MyAnnotation()
public class MyClass {
	@MyCopyright(author = "xxx", title = "ssxxssx", version = "1.0")
	public String init() {
		return "hello";
	}
}

package com.annotation;

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

@Target(ElementType.METHOD)
@Retention(RetentionPolicy.RUNTIME)
public @interface MyCopyright {
	String title();

	String version();

	String author();
}

package com.annotation;

import java.lang.reflect.Method;

public class Test {
	public static void main(String[] args) {
		try {
			Class clazz = Class.forName("com.annotation.MyClass");

			Method[] methods = clazz.getMethods();

			boolean right = clazz.isAnnotationPresent(MyAnnotation.class);

			if (right) {
				MyAnnotation annotation = (MyAnnotation) clazz
						.getAnnotation(MyAnnotation.class);

				System.out.println(annotation.myvalue());
			}

			for (Method method : methods) {
				if (method.isAnnotationPresent(MyCopyright.class)) {
					MyCopyright mc = method.getAnnotation(MyCopyright.class);

					System.out.println(mc.author() + "\n" + mc.title() + "\n"
							+ mc.version());
				}
			}

		} catch (ClassNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
}