测试代码：

package com.yanek.util.json;

import java.util.ArrayList;
import java.util.List;

import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import com.google.gson.JsonElement;
import com.google.gson.JsonParser;

public class GsonUtil {

	/**
	 * @param args
	 */
	public static void main(String[] args) {

		Hotel h1=new Hotel();
		h1.setId(1);
		h1.setName("name1");
		
		Hotel h2=new Hotel();
		h2.setId(2);
		h2.setName("name2");
		
		RoomTypeVO t1=new RoomTypeVO();
		t1.setPrice("20");
		t1.setTypeid(1);
		t1.setTypename("nnn1");
		
		List<RoomTypeVO> RoomTypeVOs=new ArrayList<RoomTypeVO>();
		RoomTypeVOs.add(t1);
		RoomTypeVOs.add(t1);
		h1.setRoomTypeVOs(RoomTypeVOs);
		
		
		Hotel hotel=new Hotel();
		
		System.out.println("json1:::"+bean2Json(h1));
		
		String s=bean2Json(h1);
		hotel=json2Bean(s,Hotel.class);
		
		System.out.println("json2:::"+bean2Json(hotel));
		
		System.out.println("json3:::"+bean2Json(RoomTypeVOs));
		
		String s2=bean2Json(RoomTypeVOs);
		List<RoomTypeVO> RoomTypeVOs2=new ArrayList<RoomTypeVO>();
		RoomTypeVOs2=json2Bean(s2,List.class);
		
		System.out.println("json4:::"+bean2Json(RoomTypeVOs2));
		
		

	}
	
	
	    private static Gson gson = new GsonBuilder().create();
	    
	    public static String bean2Json(Object obj){
	        return gson.toJson(obj);
	    }
	    
	    public static <T> T json2Bean(String jsonStr,Class<T> objClass){
	        return gson.fromJson(jsonStr, objClass);
	    }
	    
	    public static String jsonFormatter(String uglyJsonStr){
	        Gson gson = new GsonBuilder().setPrettyPrinting().create();
	        JsonParser jp = new JsonParser();
	        JsonElement je = jp.parse(uglyJsonStr);
	        String prettyJsonString = gson.toJson(je);
	        return prettyJsonString;
	    }

}

json1:::{"RoomTypeVOs":[{"typeid":1,"typename":"nnn1","price":"20"},{"typeid":1,"typename":"nnn1","price":"20"}],"id":1,"name":"name1"}
json2:::{"RoomTypeVOs":[{"typeid":1,"typename":"nnn1","price":"20"},{"typeid":1,"typename":"nnn1","price":"20"}],"id":1,"name":"name1"}
json3:::[{"typeid":1,"typename":"nnn1","price":"20"},{"typeid":1,"typename":"nnn1","price":"20"}]
json4:::[{"typeid":1.0,"typename":"nnn1","price":"20"},{"typeid":1.0,"typename":"nnn1","price":"20"}]

package com.yanek.util.json;



import java.util.List;

public class Hotel {

	public List<RoomTypeVO> getRoomTypeVOs() {
		return RoomTypeVOs;
	}
	public void setRoomTypeVOs(List<RoomTypeVO> roomTypeVOs) {
		RoomTypeVOs = roomTypeVOs;
	}
	private List<RoomTypeVO> RoomTypeVOs;
	

	public int getId() {
		return id;
	}
	public void setId(int id) {
		this.id = id;
	}

	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	private int id;
	private String name;
	

}

package com.yanek.util.json;


public class RoomTypeVO {
	

	public int getTypeid() {
		return typeid;
	}
	public void setTypeid(int typeid) {
		this.typeid = typeid;
	}

	public String getTypename() {
		return typename;
	}
	public void setTypename(String typename) {
		this.typename = typename;
	}

	public String getPrice() {
		return price;
	}
	public void setPrice(String price) {
		this.price = price;
	}
	private int typeid;
	private String typename;
	private String price;

}