Use of the Json-lib class library

Use of the Json-lib class library
The json-lib package is a Java class library that converts Java objects (including beans, maps, collections, java arrays, xml, and so on) to JSON. In the same way, Google also launched a class library named Gson, which achieves the same effect. I will not talk about it today. Preparations: first, we need to download the jar package of json-lib and import the project. Because the usage is very simple, the code is displayed here. 1. First, write a json tool class, input 2 parameters, 1 is the json identifier (custom), 2 is the object to be converted to json string format copy code 1 package com. lcw. json. util; 2 3 import net. sf. json. JSONObject; 4 5 public class MakeJson {6 7/** 8*9 * @ param key json identifier 10 * @ param value json content (multiple types, class types, strings, list set, etc.) 11 * @ return returns a json expression 12 */13 public static String getJson (String key, Object value) {14 JSONObject jsonObject = new JSONObject (); 15 jsonObject. put (key, value); // assign 16 String info = jsonobject to the jsonObject object. toString (); 17 return info; 18} 19 20} copy code 2. Provide a data source class copy code 1 package com. lcw. json. service; 2 3 import java. util. arrayList; 4 import java. util. hashMap; 5 import java. util. list; 6 import java. util. map; 7 8 import com. lcw. json. vo. person; 9 10 public class JsonService {11 12 // get a Person object 13 public Person getPerson () {14 Person person Person = new Person (1, "tuzi", 22 ); // instantiate a Person object 15 return person; 16} 17 18 // get a List set (storing the Person type) 19 public List <Person> getListPerson () {20 List <Person> list = new ArrayList <Person> (); 21 Person person1 = new Person (1, "lcw", 20 ); 22 Person person2 = new Person (2, "tuzi", 22); 23 list. add (person1); 24 list. add (person2); 25 return list; 26 27} 28 // get a List set (String type) 29 public List <String> getInfo () {30 List <String> list = new ArrayList <String> (); 31 list. add ("Beijing"); 32 list. add ("Shanghai"); 33 list. add ("Guangzhou"); 34 return list; 35} 36 37 38 // get a List set (storing the Map type) 39 public List <Map <String, object> getListPersons () {40 List <Map <String, Object> list = new ArrayList <Map <String, Object> (); 41 42 Map <String, object> map1 = new HashMap <String, Object> (); 43 Person person1 = new Person (1, "lcw", 20); 44 map1.put ("person1", person1 ); 45 46 Map <String, Object> map2 = new HashMap <String, Object> (); 47 Person person2 = new Person (2, "tuzi", 22 ); 48 map2.put ("person2", person2); 49 50 list. add (map1); 51 list. add (map2); 52 53 return list; 54 55} 56 57 58} copy code 3. Copy code 1 package com. lcw. json. vo; 2 3 public class Person {4 5 private int id; 6 private String name; 7 private int age; 8 9 public Person (int id, String name, int age) {10 super (); 11 this. id = id; 12 this. name = name; 13 this. age = age; 14} 15 16 public int getId () {17 return id; 18} 19 20 public void setId (int id) {21 this. id = id; 22} 23 24 public String getname () {25 return name; 26} 27 28 public void setname (String name) {29 this. name = name; 30} 31 32 public int getAge () {33 return age; 34} 35 36 public void setAge (int age) {37 this. age = age; 38} 39 40 @ Override41 public String toString () {42 return "Person [age =" + age + ", id =" + id + ", name = "+ name +"] "; 43} 44 45} copy Code 4. Test class copy code 1 package com. lcw. json. test; 2 3 import java. util. list; 4 import java. util. map; 5 6 import org. junit. test; 7 8 import com. lcw. json. service. jsonService; 9 import com. lcw. json. util. makeJson; 10 import com. lcw. json. vo. person; 11 12 public class JsonTest {13 14 @ Test15 public void getPersonJson () {16 JsonService jsonService = new JsonService (); 17 Person p1 = jsonService. getPerson (); 18 String info = MakeJson. getJson ("person", p1); 19 System. out. println (info); 20} 21 22 @ Test23 public void getListPersonJson () {24 JsonService jsonService = new JsonService (); 25 List <Person> persons = jsonService. getListPerson (); 26 String info = MakeJson. getJson ("persons", persons); 27 System. out. println (info); 28 29} 30 31 @ Test32 public void getListString () {33 JsonService jsonService = new JsonService (); 34 List <String> news = jsonService. getInfo (); 35 String info = MakeJson. getJson ("info", news); 36 System. out. println (info); 37} 38 39 @ Test40 public void getListPersonsJson () {41 JsonService jsonService = new JsonService (); 42 List <Map <String, Object> persons = jsonService. getListPersons (); 43 String info = MakeJson. getJson ("persons", persons); 44 System. out. println (info); 45 46} 47 48 49}