JSONObject String、实体类 list 转换

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);

 
集合转换
 
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());
————————————————
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 );   

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;

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

JSONObject String、实体类 list 转换

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