JSONObject获取java list
JSONObject -->> JSONArray
jsonObject .getJSONArray("list")
JSONArray --> list
JSONArray.parseArray(JSONArray.toJSONString(), bean.class)
JSONObject与String、实体类互相转换
//实体类对象转换成String类型的JSON字符串
JSONObject.toJSONString(实体类对象) == String
//String类型的JSON字符串转换成实体类对象
JSONObject.toJavaObject(JSON字符串,实体类对象) == 实体
//Json字符串转换成JSONObject对象
JSONObject.parseObject(JSON字符串) == JSONObject
//JSON字符串转换成实体类对象
JSONObject.parseObject(JSON字符串,实体类对象) == 实体
eg:
User u = new User();
String jsonStr = JSONObject.toJSONString(u);
String jsonStr = "{"userName":"admin"}";
Refund r = JSONObject.toJavaObject(jsonStr,User.class);
JSONObject jsonObject = JSONObject.parseObject(jsonStr);
User u = JSONObject.parseObject(jsonStr,User.class);
List<ExamListInVO> list = new ArrayList<ExamListInVO>();
list = JSONObject.parseArray(strResult, ExamListInVO.class);
JSONObject获取JSONArray转JSONObject获取某个属性值
String httpPost4Instream = http.httpPost4Instream
JSONObject jsonbject = JSONObject.fromObject(httpPost4Instream);
JSONArray jsonArray = jsonbject.getJSONArray("stores");
String string = jsonArray.getString(0);
JSONObject fromObject = JSONObject.fromObject(string);
String startDate = fromObject.getString("startDate");
String endDate = fromObject.getString("endDate");
param.setFromDate(Long.valueOf(startDate).longValue());
param.setToDate(Long.valueOf(endDate).longValue());
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版权声明：本文为CSDN博主「weixin_40650583」的原创文章，遵循 CC 4.0 BY-SA 版权协议，转载请附上原文出处链接及本声明。
原文链接：https://blog.csdn.net/weixin_40650583/article/details/84821361
--------------------------------------------------java中--------------------------------------------------------------
1.String转JSONObject
（1）json-lib（即net.sf.json.JSONObject）
String jsonMessage = "{"语文":"88","数学":"78","计算机":"99"}";
JSONObject myJson = JSONObject.fromObject(jsonMessage);
（2）.用阿里巴巴的fastjson的jar包
String str = "{"baid":null,"32d3:":"null",433:"0x32",032:"ju9fw"}";
com.alibaba.fastjson.JSONObject jm = com.alibaba.fastjson.JSON.parseObject(str);
2.String转JSONArray
String jsonMessage = "[{'num':'成绩', '外语':88, '历史':65, '地理':99, 'object':{'aaa':'1111','bbb':'2222','cccc':'3333'}}," +
"{'num':'兴趣', '外语':28, '历史':45, '地理':19, 'object':{'aaa':'11a11','bbb':'2222','cccc':'3333'}}," +
"{'num':'爱好', '外语':48, '历史':62, '地理':39, 'object':{'aaa':'11c11','bbb':'2222','cccc':'3333'}}]";
JSONArray myJsonArray = JSONArray.fromObject(jsonMessage);
System.out.println(myJsonArray);
3.String转Map
(1)json-lib（即net.sf.json.JSONObject）
String jsonMessage = "{"语文":"88","数学":"78","计算机":"99"}";
JSONObject myJson = JSONObject.fromObject(jsonMessage);
Map m = myJson;
（2）用阿里巴巴的fastjson的jar包
String str = "{"baid":null,"32d3:":"null",433:"0x32",032:"ju9fw"}";
Map mapTypes = com.alibaba.fastjson.JSON.parseObject(str);
(3) (需要引入jackjson的core、databind、annotations三个jar包 )
String json = "{"PayPal key2":"PayPal value2","PayPal key1":"PayPal value1","PayPal key3":"PayPalvalue3"}";
ObjectMapper mapper = new ObjectMapper();
Map<String,Object> m = mapper.readValue(json, Map.class);
(4)(特殊格式的String)
String a ="{se=2016, format=xml, at=en co=3}";
a = a.substring(1, a.length()-1);
Map docType = new HashMap();
Java.util.StringTokenizer items;
for(StringTokenizer entrys = new StringTokenizer(a, ", ");entrys.hasMoreTokens();
docType.put(items.nextToken(), items.hasMoreTokens() ? ((Object) (items.nextToken())) : null)){
items = new StringTokenizer(entrys.nextToken(), "=");
}
（5）Gson
Map map = new Gson().fromJson(jsonStr,Map.class);
4.JSONObject、JSONArray，Map转String
JSONObject——String：
System.out.println(myJsonObject);//可直接输出JSONObject的内容
myJsonObject.toString();
阿里巴巴fastjson：
String str = JSON.toJSONString(obj,SerializerFeature.BrowserCompatible);
JSONArray——String：
System.out.println(myJsonArray);//可直接输出myJsonArray的内容
myJsonArray.toString();
Map——String:
System.out.println(map);//可直接输出map的内容
map.toString();
5.JSONObject转JSONArray
6.JSONObject转Map
JSONObject myJson = JSONObject.fromObject(jsonString);
Map m = myJson;
7.JSONArray转JSONObject
for(int i=0 ; i < myJsonArray.length() ;i++){
//获取每一个JsonObject对象
JSONObject myjObject = myJsonArray.getJSONObject(i);
}
8.JSONArray转Map
先jsonArray先循环取出jsonObject，在转成Map
9.Map转JSONObject
（1）json-lib（即net.sf.json.JSONObject）
JSONObject json = JSONObject.fromObject( map );
或
String jsonString = JSON.toJSONString(map,SerializerFeature.WriteMapNullValue,SerializerFeature.WriteNullStringAsEmpty);
（2）alibaba的fastjson
JSONObject json = JSON.parseObject(str);
Map转json格式的String
JSON.toJSONString(map, SerializerFeature.BrowserCompatible).replace("\\u", "\u");
//需要引入alibaba的fastjson包
10.Map转JSONArray
JSONArray.fromObject(map);
11.List转JSONArray
JSONArray jsonArray2 = JSONArray.fromObject( list );
fastjson：List转JSONArray
（1）List<Object> list1 = new ArrayList<Object>();
list1.add("false");
list1.add(true);
list1.add(null);
list1.add(0x13e);
list1.add(0123);
JSONArray array1 = JSONArray.parseArray(JSON.toJSONString(list1));
（2）JSONArray jsonArray = new JSONArray(list1) ;
12.JSONArray转List
List<Map<String,Object>> mapListJson = (List)jsonArray;
或
public static List<Map<String, Object>> jsonArrayToList(JSONArray ja){
return JSONArray.toJavaObject(ja, List.class);
}
jsonArray转实体类list：
Student[] ss =(Student[])net.sf.json.JSONArray.toArray(jsonArray,Student.class);
fastjson：JSONArray转List
JSONArray arr = new JSONArray();
arr.add(0,"13");
arr.add(1,"jo");
arr.add(2,"kpo");
List<String> list = JSONObject.parseArray(array.toJSONString(), String.class);
JSONArray array = new JSONArray();
List<T> list = JSONObject.parseArray(array.toJSONString(), T.class);
13.String转数组
String string = "a,b,c";
String [] stringArr= string.split(","); //注意分隔符是需要转译滴...
如果是"abc"这种字符串,就直接
String string = "abc" ;
char [] stringArr = string.toCharArray(); //注意返回值是char数组
如果要返回byte数组就直接使用getBytes方法就ok了~~
String string = "abc" ;
byte [] stringArr = string.getBytes();
String转List
String str = "";
List<T> list = JSONObject.parseArray(str, T.class);
或net.sf.json
String arrayStr="[{"name":"JSON","age":"24","address":"北京市西城区"},{"name":"JSON2","age":"24","address":"北京市西城区"}]";
//转化为list
List<Student> list2=(List<Student>)net.sf.json.JSONArray.toList(net.sf.json.JSONArray.fromObject(arrayStr), Student.class);
数组转String
char[] data={a,b,c};
String s=new String(data);
14.java实体类的List转String
JSON与String关系比较近，而JSON的子类JSONArray又和List关系比较近，故把JSONArray做中介过渡：
import com.alibaba.fastjson.JSONArray;
public String list2str(List<?> list){
JSONArray jsonArray = (JSONArray) JSONArray.toJSON(list); //List转JSONArray
System.out.println(jsonArray.toString());
return jsonArray.toJSONString(); //JSONArray比较容易转String
}
15.Array、List、Set之间转换：
String[] arr = new String[]{"Tom", "Bob", "Jane"};
//Array转List
List<String> arr2list = Arrays.asList(arr);
//Array转Set
Set<String> arr2set = new HashSet<String>(Arrays.asList(arr));
//List转Array
Object[] list2arr = arr2list.toArray();
//List转Set
Set<String> list2set = new HashSet<>(arr2list);
//Set转Array
Object[] set2arr = list2set.toArray();
//Set转List
List<String> set2list = new ArrayList<>(arr2set);
List<String> list = new ArrayList<String>(new HashSet<String>());//
16.java对象转JsonObject
Student stu=new Student();
stu.setName("JSON");
stu.setAge("23");
stu.setAddress("北京市西城区");
net.sf.json.JSONObject json = net.sf.json.JSONObject.fromObject(stu);
或alibaba的fastjson：
JSONObject json = (JSONObject) JSONObject.toJSON(stu);
17.java对象转jsonArray
Student stu=new Student();
stu.setName("JSON");
stu.setAge("23");
stu.setAddress("北京市西城区");
net.sf.json.JSONArray array = net.sf.json.JSONArray.fromObject(stu);
但alibaba的fastjson报错：
//JSONArray array = (JSONArray) JSONArray.toJSON(stu);//报错
18.JsonObject转java对象
Student stu=(Student)JSONObject.toBean(jsonObject, Student.class);
19.jsonArray转java对象
jsonArray先循环取出jsonObject，再转成java对象