gson 转换json数据利器

gson 数据转换json

package com.data.vo;

import com.google.gson.annotations.Expose;

public class GsonUser {
	@Expose
	private Integer gson_id;
	private String gson_name;
	public Integer getGson_id() {
		return gson_id;
	}
	
	public void setGson_id(Integer gson_id) {
		this.gson_id = gson_id;
	}
	public String getGson_name() {
		return gson_name;
	}
	public void setGson_name(String gson_name) {
		this.gson_name = gson_name;
	}

	public GsonUser(Integer gson_id, String gson_name) {
		super();
		this.gson_id = gson_id;
		this.gson_name = gson_name;
	}

	public GsonUser() {
		super();
	}
}

package com.data.test;

import java.lang.reflect.Type;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.junit.Before;
import org.junit.Test;

import com.data.vo.GsonUser;
import com.google.common.reflect.TypeToken;
import com.google.gson.Gson;
import com.google.gson.GsonBuilder;


public class Commontest {
	
	private Gson gson = null; 
	  
    private GsonBuilder gsonBuilder = null; 
    String gsonToString  = null;
    GsonUser gsonUser1 = new GsonUser(1,"美女");
	GsonUser gsonUser2 = new GsonUser(2,"帅哥");
    @Before
	public void setup(){
		gson = new Gson();
		gsonBuilder = new GsonBuilder();
	}

	//@Test bean
	public void testGson(){
		GsonUser gsonUser = new GsonUser();
		gsonUser.setGson_id(1);
		gsonUser.setGson_name("美女");
		GsonBuilder builder = new GsonBuilder();
		 // 不转换没有 @Expose 注解的字段
		//builder.excludeFieldsWithoutExposeAnnotation();
		Gson gson =builder.create();
		String user = gson.toJson(gsonUser);
		System.out.println(user);//{"gson_id":1,"gson_name":"美女"}
		 // 将JSON字符串转换为 JavaBean
		GsonUser user2 = gson.fromJson(user, GsonUser.class);
		System.out.println(user2.getGson_id()+","+user2.getGson_name());
	}
	
	//@Test  
	public void testList(){//list
		List<Object> list = new ArrayList<Object>();
		
		list.add(gsonUser1);list.add(gsonUser2);
		gsonToString= gson.toJson(list);
		//System.out.println(gsonToString);
		//TypeToken 通过反射 type import java.lang.reflect.Type; 将泛型对象类型转成我们所需要的对象类型  //import com.google.common.reflect.TypeToken;
		Type type = new TypeToken<List<GsonUser>>() {}.getType();//list 对象必须指定一个实体类。
		List<GsonUser> list1  = gson.fromJson(gsonToString.toString(), type);
		for (int i = 0; i < list1.size(); i++) {
			GsonUser gs = (GsonUser) list1.get(i);
			System.out.println(gs.getGson_id()+","+gs.getGson_name());
		}
		
	}
	
	@Test
	public void testMap(){//map
		Map<String, GsonUser> userMap = new HashMap<String, GsonUser>();
		userMap.put("gs", gsonUser1);userMap.put("ps1", gsonUser2);
		String gsonToString =gson.toJson(userMap);
		System.out.println(gsonToString);
		Type type = new TypeToken<Map<String,GsonUser>>() {}.getType();
		Map<String, GsonUser> map  = gson.fromJson(gsonToString, type);
		GsonUser u = map.get("gs");
		System.out.println(u.getGson_id()+","+u.getGson_name());	
	}
}

另外还有阿里巴巴的fastjson也不错

Fastjson API入口类是com.alibaba.fastjson.JSON，常用的序列化操作都可以在JSON类上的静态方法直接完成。
public static final Object parse(String text); // 把JSON文本parse为JSONObject或者JSONArray
public static final JSONObject parseObject(String text)； // 把JSON文本parse成JSONObject   
public static final <T> T parseObject(String text, Class<T> clazz); // 把JSON文本parse为JavaBean
public static final JSONArray parseArray(String text); // 把JSON文本parse成JSONArray
public static final <T> List<T> parseArray(String text, Class<T> clazz); //把JSON文本parse成JavaBean集合
public static final String toJSONString(Object object); // 将JavaBean序列化为JSON文本
public static final String toJSONString(Object object, boolean prettyFormat); // 将JavaBean序列化为带格式的JSON文本
public static final Object toJSON(Object javaObject); 将JavaBean转换为JSONObject或者JSONArray。

这里就不联系demo了
http://blog.csdn.net/wilsonke/article/details/37921571