Gson 工具类

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

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

/**
 * gson 工具类
 * 注：
 * 不需要解析和反解析的字段都要加上transient
 * 比如：
 * transient Uri CONTENT_URI = Uri.parse("content://" + MoImContent.AUTHORITIE + "/imcloud_group_member”);
 * 如果这 Uri 不加上transient会导致解析和反解析异常。
 * Created by huangrenqian833 on 2018/6/15.
 */

public class GsonUtils {
    private static final String TAG = GsonUtils.class.getSimpleName();
    private static volatile GsonUtils instance;
    private Gson gson = null;

    private GsonUtils(Gson gson) {
        this.gson = gson;
    }

    public static GsonUtils getInstance() {
        if (instance == null) {
            synchronized (GsonUtils.class) {
                if (instance == null) {
                    instance = new GsonUtils(new Gson());
                }
            }
        }
        return instance;
    }

    /**
     * 转成String
     *
     * @param object object
     * @return String
     */
    public String jsonToString(Object object) {
        try {
            return gson.toJson(object);
        } catch (Exception e) {
            Log.e(TAG, e.getMessage());
        }
        return "";
    }

    /**
     * 转成bean
     *
     * @param jsonString 字符串
     * @param cls        目标 jsonObject
     * @return jsonObject
     */
    public <T> T jsonToBean(String jsonString, Type cls) {
        try {
            return gson.fromJson(jsonString, cls);
        } catch (Exception e) {
            Log.e(TAG, e.getMessage());
        }
        return null;
    }

    /**
     * 转成bean
     *
     * @param jsonString 字符串
     * @param cls        目标 jsonObject
     * @return jsonObject
     */
    public <T> T jsonToBean(String jsonString, Class<T> cls) {
        try {
            return gson.fromJson(jsonString, cls);
        } catch (Exception e) {
            Log.e(TAG, e.getMessage());
        }
        return null;
    }

    public <T> T jsonToBeanThrow(String jsonString, Class<T> cls) {
            return gson.fromJson(jsonString, cls);

    }

    /**
     * 转成list
     *
     * @param jsonString 字符串
     * @param cls        目标 jsonObject
     * @return 目标 jsonObject list
     */
    public <T> List<T> jsonToList(String jsonString, Class<T> cls) {
        try {
            List<T> list = new ArrayList<>();
            JsonArray array = new JsonParser().parse(jsonString).getAsJsonArray();
            for (final JsonElement elem : array) {
                list.add(gson.fromJson(elem, cls));
            }
            return list;
        } catch (Exception e) {
            Log.e(TAG, e.getMessage());
        }
        return null;
    }

    /**
     * 转成ArrayList
     *
     * @param jsonString 字符串
     * @param cls        目标 jsonObject
     * @return 目标 jsonObject list
     */
    public <T> ArrayList<T> jsonToArrayList(String jsonString, Class<T> cls) {
        try {
            ArrayList<T> list = new ArrayList<>();
            JsonArray array = new JsonParser().parse(jsonString).getAsJsonArray();
            for (final JsonElement elem : array) {
                list.add(gson.fromJson(elem, cls));
            }
            return list;
        } catch (Exception e) {
            Log.e(TAG, e.getMessage());
        }
        return null;
    }
}