gson/fastjson 的基本用法

字符串转对象

String string = SPUtils.getString(configsp, SPConfigs.DEPT_CONFIG, "");
 userBean parse = JSON.parseObject(string, userBean.class);

将对象转换为JSON字符串

  UserInfo info=new UserInfo();
  info.setName("zhangsan");
  info.setAge(24);
  String strJson=JSON.toJSONString(info);

常用API

1 public static final Object parse(String text); 　　// 把JSON文本parse为JSONObject或者JSONArray 
2 public static final JSONObject parseObject(String text)；　　 // 把JSON文本parse成JSONObject 
3 public static final T parseObject(String text, Class clazz); 　　// 把JSON文本parse为JavaBean 
4 public static final JSONArray parseArray(String text); 　　// 把JSON文本parse成JSONArray 
5 public static final List parseArray(String text, Class clazz); 　　//把JSON文本parse成JavaBean集合 
6 public static final String toJSONString(Object object); 　　// 将JavaBean序列化为JSON文本 
7 public static final String toJSONString(Object object, boolean prettyFormat); 　　// 将JavaBean序列化为带格式的JSON文本 
8 public static final Object toJSON(Object javaObject); 　　//将JavaBean转换为JSONObject或者JSONArray。

GSON的基本用法

 for (int i = 0; i < permissionArray.length; i++) {
        PermissionBean info = new PermissionBean();
        info.setIcon(permissionArray[i].getString("icon"));
        info.setName(permissionArray[i].getString("name"));
        info.setUrl(permissionArray[i].getString("url"));
        info.setMenuID(permissionArray[i].getString("menuID"));
        permissionList.add(info);
    }
    //对象转字符串
    Gson gson = new Gson();
    String permissionJson = gson.toJson(permissionList);
    PreferencesUtil.putString(NovaApplication.instance(), PreferencesUtil.PRE_KEY_PERMISSION, permissionJson);
}

集合或者对象转换成JsonString

public List<PermissionBean> getPermissionList() {
    List<PermissionBean> permissionList = null;
    if (permissionList == null) {
        String shopListStr = PreferencesUtil.getString(NovaApplication.instance(), PreferencesUtil.PRE_KEY_PERMISSION);
        Gson gson = new Gson();
        Type perType = new TypeToken<ArrayList<PermissionBean>>() {
        }.getType();
        permissionList = gson.fromJson(shopListStr, perType);
    }
    return permissionList;
}
       Gson gson = new Gson();
        String jsonObject = gson.toJson(list);

字符串转实体类

public Shop getCurrentShopInfo() {
    String shopMsg = PreferencesUtil.getString(KmmApplication.getInstance(), PreferencesUtil.PRE_KEY_CURRENT_SHOP_INFO);
    LogPrint.w("TAG", "shopString--get" + shopMsg);
    if (!StringHelper.isEmpty(shopMsg)) {
        Gson gson = new Gson();
        currentShopInfo = gson.fromJson(shopMsg, Shop.class);
    }
    return currentShopInfo;
}

获取主要信息 字符串转集合

    public List<AuthInfo> getMainAuthList() {
        if (mMainAuthList == null) {
            String shopListStr = PreferencesUtil.getStringWithFileNmae(this, PreferencesUtil.PRE_KEY_AUTH_MAIN, PreferencesUtil.PREFERENCE_NAME_AUTH);
            Gson gson = new Gson();
            Type shopListType = new TypeToken<ArrayList<AuthInfo>>() {
            }.getType();
            mMainAuthList = gson.fromJson(shopListStr, shopListType);
        }
        return mMainAuthList;
    }

集合转字符串

public void setShopList(List<ShopInfo> shopList) {
    this.shopList = shopList;
    Gson gson = new Gson();
    String shop = gson.toJson(shopList);
    PreferencesUtil.putString(NovaApplication.instance(), PreferencesUtil.PRE_KEY_SHOPLIST, shop);
}

字符串转为集合

public List<ShopInfo> getShopList() {
    if (null == shopList) {
        String shopListStr = PreferencesUtil.getString(NovaApplication.instance(), PreferencesUtil.PRE_KEY_SHOPLIST);
        Gson gson = new Gson();
        Type shopListType = new TypeToken<List<ShopInfo>>() {
        }.getType();
        shopList = gson.fromJson(shopListStr, shopListType);
    }
    return shopList;
}

String、JsonObject、JavaBean 互相转换
    User user = new Gson().fromJson(jsonObject, User.class);
    User user = new Gson().fromJson(string, User.class);
    String string = new Gson().toJson(user);
    JsonObject jsonObject = new Gson().toJsonTree(user).getAsJsonObject(); 
    JsonObject jsonObject = new JsonParser().parse(string).getAsJsonObject();

String、JsonArray、List互相转换
    List<User> userList = gson.fromJson(string, new TypeToken<List<User>>() {}.getType()); 
    List<User> userList = gson.fromJson(jsonArray, new TypeToken<List<User>>() {}.getType()); 
    String string = new Gson().toJson(userList); 
    JsonArray jsonArray = new Gson().toJsonTree(userList, new TypeToken<List<User>>() {}.getType()).getAsJsonArray();
    JsonArray jsonArray = new JsonParser().parse(string).getAsJsonArray();