fastjson的一些常见用法

前端之家收集整理的这篇文章主要介绍了fastjson的一些常见用法前端之家小编觉得挺不错的,现在分享给大家,也给大家做个参考。
1、创建一个json对象:
@H_403_5@
[1]通过解析一个json字符串生成一个json对象(json字符串就是已经按照json格式组装的字符串)
@H_403_5@String jsonString = "{\"key1\":\"value1\"}";
@H_403_5@JSONObject aJsonObj = JSONObject.parSEObject(jsonString);
@H_403_5@这时aJsonObj就是一个下面格式的json对象:
@H_403_5@{
@H_403_5@"key1":"value1"
@H_403_5@}
@H_403_5@
@H_403_5@[2]直接new一个json对象
@H_403_5@JSONObject aJsonObj = new JSONObject();
@H_403_5@aJsonObj.put("text","hello,this is Json.hou");
@H_403_5@aJsonObj.put("time","34.102111");
@H_403_5@此时aJsonObj就是一个下面格式的json对象:
@H_403_5@{
@H_403_5@"text":"hello,this is Json.hou",
@H_403_5@"time":"34.102111"
@H_403_5@}
@H_403_5@
2、json对象转字符串
@H_403_5@String strJson = aJsonObj.toJSONString();
@H_403_5@
3、向 json中插入数据
@H_403_5@
String jsonString = "{\"key1\":\"value1\"}";@H_403_5@ //一个按照Json格式组织内容的字符串jsonString
@H_403_5@JSONObject outJson = JSONObject.parSEObject(jsonString);//从一个字符串中解析生成一个Json对象outJson
@H_403_5@outJson.put("inkey2",12.63); @H_403_5@ //向Json对象outJson中插入浮点数据12.63
@H_403_5@JSONObject inJson = new JSONObject();@H_403_5@ //以new的方式创建一个全新的json对象inJson
@H_403_5@inJson.put("inkey1","this is a string value");@H_403_5@ //向Json对象inJson中插入一个字符串
@H_403_5@inJson.put("inkey2",12);@H_403_5@ //向Json对象inJson中插入一个整形数字@H_403_5@
@H_403_5@outJson.put("injson_key",inJson);@H_403_5@ //向Json对象outJson插入一个Json对象inJson
@H_403_5@执行完上述操作后,outJson的内容为:
@H_403_5@{"injson_key":{"inkey1":"this is a string value","inkey2":12},"outkey":12.63,"srcKey":"srcValue"}
@H_403_5@
4、Json对象的全部内容或者清除一项内容
@H_403_5@清除一项的函数:remove()
@H_403_5@清空所有项的函数:clear()
@H_403_5@例如,有如下代码
@H_403_5@JSONObject testJson = new JSONObject();
@H_403_5@testJson.put("key1","this is a string value");
@H_403_5@testJson.put("key2",12);
@H_403_5@testJson.put("key3","hello");
@H_403_5@testJson.remove("key2");@H_403_5@ //@H_403_5@ 清除key2的内容
@H_403_5@testJson.clear();@H_403_5@ //清空Json对象的全部内容@H_403_5@
@H_403_5@开始时的内容为:
@H_403_5@{"key1":"this is a string value","key2":12,"key3":"hello"}
@H_403_5@清除项key2之后的内容为:
@H_403_5@{"key1":"this is a string value","key3":"hello"}
@H_403_5@清空操作之后的内容为空Json
@H_403_5@{}


5、Json数组
@H_403_5@JSONArray可表示一个Json数组,可参考如下示例程序:
@H_403_5@JSONObject testOutJson = new JSONObject();
@H_403_5@testOutJson.put("outJson","~~~this is out json ");
@H_403_5@JSONArray testJsonArray = new JSONArray();//创建一个Json数组对象
@H_403_5@for(int i=0; i<3;i++)
@H_403_5@{
@H_403_5@JSONObject aJsonMember = new JSONObject();
@H_403_5@aJsonMember.put("keya1","heihei");
@H_403_5@aJsonMember.put("keya2","hahaha");
@H_403_5@testJsonArray.add(aJsonMember);//向Json数组对象中添加Json对象
@H_403_5@}
@H_403_5@testOutJson.put("jarry",testJsonArray);//将Json数组对象添加到Json对象中执行完上述操作之后的testOutJson的内容为:{"jarry":[{"keya1":"heihei","keya2":"hahaha"},{"keya1":"heihei","keya2":"hahaha"}],"outJson":"~~~this is out json "}
原文链接:https://www.f2er.com/json/290054.html

猜你在找的Json相关文章