类似Spring Controller 注解Demo

花点时间弄的一个url和方法映射的小Demo，先记录在此，便于后面使用。
Note：使用场景：Mina，Netty的Client->Server请求映射关系。 后期有时间再加上一个类级的映射，以达到模块划分之间的划分更清晰。

1、Mapper 映射关系的Annotation类。

package com.runant.demo;
import java.lang.annotation.Retention;
import java.lang.annotation.Target;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.ElementType;

/**
 * @author ping
 *
 */
@Target({ElementType.METHOD, ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
public @interface Mapper {
	String value() default "";
}

2、UserService 这里用于测试的案例业务类。

package com.runant.demo;
/**
 * @author ping
 * 
 */
@Mapper(value = "/user")
public class UserService {

    @Mapper(value = "/getUser")
    public String getUser(String userName) {
        return "Hello...." + userName;
    }

    @Mapper(value = "/login")
    public boolean login(String userName, String password) {
        System.out.println("Login user-name:" + userName + ",password:" + password);
        return "admin".equals(userName) && "123456".equals(password);
    }

    public boolean delete(String userName) {
        System.out.println("Delete user-name:" + userName);
        return true;
    }
}

3、Test 用于测试的类。

package com.runant.demo;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.HashMap;
import java.util.Map;

/**
 * @author ping
 * 
 */
public class Test {

	/**
	 * @param args
	 * @throws InvocationTargetException
	 * @throws IllegalAccessException
	 * @throws IllegalArgumentException
	 */
	public static void main(String[] args) throws IllegalArgumentException, IllegalAccessException, InvocationTargetException {
//		String url = "/user/getUser";
		String url = "/user/login";
		String params = "Test ,Hahahha~!~";
		
		 Map<String, Invoker> urlMapping = new HashMap<String, Invoker>();
        UserService service = new UserService();
        Mapper topMapper = service.getClass().getAnnotation(Mapper.class);
        String topUrl = topMapper != null ? topMapper.value() : "";
        Method[] methods = service.getClass().getDeclaredMethods();
        for (Method m : methods) {
            Mapper subMapper = (Mapper) m.getAnnotation(Mapper.class);
            if (subMapper != null) {
                urlMapping.put(topUrl + subMapper.value(), new Invoker(service, m));
            }
        }
		Invoker invoker = urlMapping.get(url);
//		Object result = invoker.execute(params);
		Object result = invoker.execute("Leo","123");
		System.out.println(result);
		result = invoker.execute("admin","123456");
		System.out.println(result);
		
	}

	private static class Invoker {
		private Method method;
		private Object obj;

		public Invoker(Object obj, Method method) {
			this.obj = obj;
			this.method = method;
		}

		public Object execute(Object... args){
			try {
				return this.method.invoke(obj, args);
			} catch (IllegalArgumentException e) {
				e.printStackTrace();
			} catch (IllegalAccessException e) {
				e.printStackTrace();
			} catch (InvocationTargetException e) {
				e.printStackTrace();
			}
			return null;
		}
	}
}