JsonUtil工具类的封装

首先在app/build.gradle文件中添加依赖：

compile 'com.google.code.gson:gson:2.8.0'//Gson依赖注入

import android.text.TextUtils;

import com.google.gson.Gson;

import org.json.JSONException;
import org.json.JSONObject;

import java.util.Iterator;
import java.util.Map;

/**
 * Created by Administrator on 2016/11/29.
 */
public class JsonUtil {
    //json转换成bean类
    public static  T jsonString2Obj(String json, Class clazz) {
        if (TextUtils.isEmpty(json) || clazz == null) {
            return null;
        }
        return new Gson().fromJson(json, clazz);
    }

    //bean类转换成json字符串
    public static String obj2JsonString(Object obj) {
        if (obj == null) {
            return null;
        }
        return new Gson().toJson(obj);
    }

    //map集合转换成json字符串
    public static String map2JsonString(Map map) throws JSONException {
        if (map == null || map.size() == 0) {
            return null;
        }
        Iterator> iterator = map.entrySet().iterator();
        JSONObject jsonObject = new JSONObject();
        while (iterator.hasNext()) {
            Map.Entry mapNext = iterator.next();
            jsonObject.put(mapNext.getKey(), mapNext.getValue());
        }
        if (jsonObject != null) {
            return jsonObject.toString();
        } else {
            return null;
        }
    }
}