generictest.java

疯狂Java讲义_源码(含Java设计模式CHM

import java.lang.reflect.*;
import java.util.*;

/**
 * Description:
 * <br/>Copyright (C), 2008-2010, Yeeku.H.Lee
 * <br/>This program is protected by copyright laws.
 * <br/>Program Name:
 * <br/>Date:
 * @author  Yeeku.H.Lee [e-mail]
 * @version  1.0
 */
public class GenericTest
{
	private Map<String , Integer> score;
	public static void main(String[] args)
		throws Exception
	{
		Class<GenericTest> clazz = GenericTest.class;
		Field f = clazz.getDeclaredField("score");
		//直接使用getType()取出Field类型只对普通类型的Field有效
		Class<?> a = f.getType();
		System.out.println("score的类型是:" + a);
		//获得Field实例f的泛型类型
		Type gType = f.getGenericType();
		//如果gType类型是ParameterizedType对象
		if(gType instanceof ParameterizedType)
		{
			//强制类型转换
			ParameterizedType pType = (ParameterizedType)gType;
			//获取原来类型
			Type rType = pType.getRawType();
			System.out.println("原始类型是：" + rType);
			//取得泛型类型的泛型参数
			Type[] tArgs = pType.getActualTypeArguments();
			System.out.println("泛型类型是:");
			for (int i = 0; i < tArgs.length; i++) 
			{
				System.out.println("第" + i + "个泛型类型是：" + tArgs[i]);
			}
		}
		else
		{
			System.out.println("获取泛型类型出错！");
		}
	}
}