- com.alibaba.fastjson.JSONObject
- net.sf.json.JSONObject
- org.json.JSONObject
way conversion between the java json objects and data in general, there are two, one is referenced third-party jar package, such as Gson (Google), Fastjson (Ali), Jackson, etc., in this way the advantage is concise syntax, you can achieve a if converted, but the disadvantage is the introduction of a large third-party libraries.
The second is the direct use of Java comes org.json resolution, but this library feature comparison basis, the analysis will write a lot of duplicate code.
A, com.alibaba.fastjson.JSONObject use
1 POM.xml
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>fastjson</artifactId>
<version>1.2.51</version>
</dependency>
2 Json string conversion between Map, List, object
of java.util.ArrayList Import;
Import the java.util.HashMap;
Import java.util.List;
Import a java.util.Map;
Import com.alibaba.fastjson.JSON;
Import com.alibaba.fastjson.JSONArray;
Import com.alibaba .fastjson.JSONObject;
public class TestFastJson {
public static void main (string [] args) {
json2JsonObject (); // Json string into the target JSONObject
json2JavaBean (); // converts a string to a JavaBean Json
json2JsonArray ( ); // Json string into the target JSONArray
json2JavaBeanList (); // converts a string to a JavaBean Json set
javaBean2Json (); // a JavaBean Json format into data
javaBean2JsonObject (); // convert a JavaBean the object is JSONObject
json2ListInMap (); // Get Map Json string from the List object
the User the JSON = User.parseObject(s, User.class);
list2JsonInMap (); // Map object into a list containing Json string
stringToMap (); // json string revolutions Map
mapToString (); // Map transfected json string
mapToJsonObject (); // map turn json objects
testList2String (); // list turn json string
}
Private static void json2JsonObject () {
string S = "{\" name \ ": \" Peter \ "}";
the JSONObject Object = JSON.parseObject (S);
the System.out .println (object.get ( "name"));
}
Private static void json2JavaBean () {
String S = "{\" ID \ ": \" 17,051,801 \ ", \" name \ ": \" Lucy \ "} ";
System.out.println (user.getId ());
System.out.println (the User.getName());
}
Private static void json2JsonArray () {
String S = "[{\" ID \ ": \" 17,051,801 \ ", \" name \ ": \" Lucy \ "}, {\" ID \ ": \" 17,051,802 \ " , "name \" \: \ "Peter \"}] ";
the JSONArray JSON.parseArray = Array (S);
{for (int I = 0 ++ I;; I <array.size ())
data of // JSONArray converted to a String type requires outside plus ""; otherwise it will report the type of abnormal strong turn!
STR = array.get String (I) + "";
the JSONObject Object = JSON.parseObject (STR);
System.out.println (object.get ( "name"));
}
}
Private static void json2JavaBeanList () {
String S = "
List < User> list = JSON.parseArray (s, User.class);
}
}
private static void javaBean2Json() {
User user = new User("17051801", "lucy");
String string = JSON.toJSONString(user);
System.out.println(string);
}
private static void javaBean2JsonObject() {
User user = new User("17051801", "lucy");
JSONObject json = (JSONObject) JSON.toJSON(user);
System.out.println(json.get("id"));
}
private static void json2ListInMap() {
String s = "{json:[{id:\"17051801\",\"name\":\"lucy\"},{id:\"17051802\",\"name\":\"peter\"},"
+ "{id:\"17051803\",\"name\":\"tom\"},{id:\"17051804\",\"name\":\"lily\"}]}";
// convert Json string JSONObject object value of the object list and remove
Object = JSON.parseObject the JSONObject (S);
Object objArray = object.get ( "JSON");
String objArray + STR = "";
// embodiment 1: in the form of an object is converted to JSONArray
JSONArray JSON.parseArray = Array (STR);
for (int I = 0; I <array.size (); I ++) {
the JSONObject obj = JSON.parseObject (array.get (I) + "");
System.out.println (obj.get ( "name")) ;
}
// embodiment 2: is converted to List <JavaBean> form
List <the User> List = JSON.parseArray (STR, User.class);
for (the User User: List) {
System.out.println(user.getName());
}
}
Private static void list2JsonInMap () {
// embodiment 1: Construction of an object with a list of JavaBean
School School School new new = ();
school.setId ( ". 1");
school.setName ( "schoolA");
the User new new user1 = the User ();
user1.setId ( "17,051,801");
user1.setName ( " Lucy ");
the User new new user2 = the User ();
user2.setId (" 17,051,802 ");
user2.setName (" Peter ");
. school.getStudents () the Add (user1);
. school.getStudents () the Add (user2 );
// convert the object into a JavaBean Json string
string string1 = JSON.toJSONString (School);
System.out.println (string1);
// embodiment 2: Construction of a Map objects with the list of
Map<String, Object> map1 = new HashMap<String,Object>();
map1.put("id", "17051801");
map1.put("name", "lucy");
Map<String, Object> map2 = new HashMap<String,Object>();
map2.put("id", "17051802");
map2.put("name", "peter");
List<Map<String, Object>> list = new ArrayList<Map<String, Object>>();
list.add(map1);
list.add(map2);
Map<String, Object> map = new HashMap<String,Object>();
map.put("id", "1");
map.put("name", "schoolA");
String string2 = JSON.toJSONString (map);
// convert the object into a map Json string
map.put ( "Students.", List);
System.out.println(string2);
}
private static void stringToMap(){
String str = "{\"age\":\"24\",\"name\":\"cool_summer_moon\"}";
JSONObject jsonObject = JSONObject.parseObject(str);
//json对象转Map
Map<String,Object> map = (Map<String,Object>)jsonObject;
System.out.println("map对象是：" + map);
Object object = map.get("age");
System.out.println("age的值是"+object);
}
private static void mapToString(){
Map<String,Object> map = new HashMap<>();
map.put("age", 24);
map.put("name", "cool_summer_moon");
String jsonString = JSON.toJSONString(map);
System.out.println("json string: "+ JSONString);
}
private static void mapToJsonObject(){
Map<String,Object> map = new HashMap<>();
map.put("age", 24);
map.put("name", "cool_summer_moon");
JSONObject json = new JSONObject(map);
System.out.println("Json对象是：" + json);
}
/**
* 测试包装类型的List转换为json字符串
*/
public static void testList2String() {
List<Long> longs = new ArrayList<Long>();
longs.add(1L);
longs.add(2L);
longs.add(3L);
String actual = JSON.toJSONString(longs);
Assert.assertEquals("[1,2,3]", actual);
}
}
Two, org.json.JSONObject use
1. introduced org.json dependent
<dependency> <groupId>org.json</groupId> <artifactId>json</artifactId> <version>20160810</version> </dependency>
3.JSONObject turn javaBean
public static void main(String[] args) {
String str="{\"student\":[{\"name\":\"leilei\",\"age\":23},{\"name\":\"leilei02\",\"age\":23}]}";
Student stu = null;
List<Student> list = null;
try {
ObjectMapper objectMapper=new ObjectMapper();
StudentList studentList=objectMapper.readValue(str, StudentList.class);
list=studentList.getStudent();
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
for(Student s:list){
System.out.println(s.getName());
}
}
ObjectMapper objectMapper=new ObjectMapper(); out = objectMapper.readValue(org.json.JSONObject.valueToString(arg0), OutputObject.class);
The use of three net.sf.json.JSONObject
Introducing a dependency maven
The need to retain the last line, there are two versions of the jdk realization: json-lib-2.1-jdk13.jar and json-lib-2.1-jdk15.jar
<dependency>
<groupId>net.sf.json-lib</groupId>
<artifactId>json-lib</artifactId>
<version>2.4</version>
<classifier>jdk15</classifier>
</dependency>
Examples of use
package json;
import net.sf.json.JSON;
import net.sf.json.JSONObject;
import net.sf.json.xml.XMLSerializer;
public class JSONObject_1_3 {
public static void javaToJSON() {
System.out.println("java代码封装为json字符串");
JSONObject jsonObj = new JSONObject();
jsonObj.put("username", "张三");
jsonObj.put("password", "123456");
System.out.println("java--->json \n" + jsonObj.toString());
}
public static void jsonToJAVA() {
System.out.println("json字符串转java代码");
String jsonStr = "{\"password\":\"123456\",\"username\":\"张三\"}";
JSONObject jsonObj = JSONObject.fromString(jsonStr);
String username = jsonObj.getString("username");
String password = jsonObj.optString("password");
System.out.println("json--->java\n username=" + username
+ "\t password=" + password);
}
public static void jsonToXML() {
System.out.println("json字符串转xml字符串");
String jsonStr = "{\"password\":\"123456\",\"username\":\"张三\"}";
JSONObject json = JSONObject.fromString(jsonStr);
XMLSerializer xmlSerializer = new XMLSerializer();
xmlSerializer.setRootName("user_info");
xmlSerializer.setTypeHintsEnabled(false);
String xml = xmlSerializer.write(json);
System.out.println("json--->xml \n" + xml);
System.out.println ( "turn JavaBean json string");
Public static void javaBeanToJSON () {
}
UserInfo userInfo = new UserInfo();
userInfo.setUsername("张三");
userInfo.setPassword("123456");
JSONObject json = JSONObject.fromBean(userInfo);
System.out.println("javabean--->json \n" + json.toString());
}
public static void javaBeanToXML() {
System.out.println("javabean转xml字符串");
UserInfo userInfo = new UserInfo();
userInfo.setUsername("张三");
userInfo.setPassword("123456");
JSONObject json = JSONObject.fromBean(userInfo);
XMLSerializer xmlSerializer = new XMLSerializer();
String xml = xmlSerializer.write(json, "UTF-8");
System.out.println("javabean--->xml \n" + xml);
}
public static void xmlToJSON(){
System.out.println("xml字符串转json字符串");
String xml = "<?xml version=\"1.0\" encoding=\"UTF-8\"?><user_info><password>123456</password><username>张三</username></user_info>";
JSON json=XMLSerializer.read(xml);
System.out.println("xml--->json \n"+json.toString());
}
public static void main(String args[]) {
javaToJSON();
jsonToJAVA();
jsonToXML();
javaBeanToJSON();
javaBeanToXML();
xmlToJSON();
}
}
Transfer: https://blog.csdn.net/zhengTornado/article/details/102832587