1、jackson 框架:這個框架提供了JsonGenerator ,ObjectMapper兩個類通過這兩個類提供的方法可以將java 對象轉化爲json 對象,json 數組格式,也可以將json對象、數組格式轉化爲java對象。
2、json-lib框架也可以進行json格式和java 對象之間的相互轉化,json-lib提供的類主要有:JSONObject ,JSONArray….
3、展現使用兩種框架進行相互轉化:
一、json-lib:
package com.inspur.json;
import java.util.ArrayList;
import java.util.List;
import net.sf.json.JSONArray;
import net.sf.json.JSONObject;
public class JSONTest {
public static void main(String[] args) {
User u = new User();
u.setName(“name1”);
u.setAge(1);
u.setPhone(“123”);
User u2 = new User();
u2.setName(“name2”);
u2.setAge(2);
u2.setPhone(“321”);
List list = new ArrayList();
list.add(u);
list.add(u2);
// 創建JSONObject 對象
JSONObject jobg = new JSONObject();
// 創建JSONObject 對象
JSONArray arr = new JSONArray();
// 將對象轉化爲json對象的格式
JSONObject str = jobg.fromObject(u);
// 將list集合轉化爲json數組的格式
JSONArray str1 = arr.fromObject(list);
System.out.print(str);
System.out.print("\n");
System.out.print(str1);
}
}
/* 運行結果 */
{“age”:1,”name”:”name1”,”phone”:”123”}
[{“age”:1,”name”:”name1”,”phone”:”123”},{“age”:2,”name”:”name2”,”phone”:”321”}]
二、jackson框架提供的兩個類 JsonGenerator ObjectMapper
package com.jackson.test;
import java.util.ArrayList;
import java.util.List;
import org.codehaus.jackson.JsonEncoding;
import org.codehaus.jackson.JsonGenerator;
import org.codehaus.jackson.map.ObjectMapper;
public class Test {
public static void main(String[] args) {
User u = new User();
u.setName(“name1”);
u.setAge(1);
u.setSex(“man”);
User u2 = new User();
u2.setName(“name2”);
u2.setAge(2);
u2.setSex(“man”);
List list = new ArrayList();
list.add(u);
list.add(u2);
ObjectMapper obj = new ObjectMapper();
JsonGenerator jg = null;
try {
jg = obj.getJsonFactory().createJsonGenerator(System.out,
JsonEncoding.UTF8);
System.out.println("jsonGenerator");
// writeObject可以轉換java對象,eg:JavaBean/Map/List/Array等
jg.writeObject(u);
System.out.println();
jg.writeObject(list);
System.out.println();
System.out.println("ObjectMapper");
// writeValue具有和writeObject相同的功能
obj.writeValue(System.out, list);
} catch (Exception e) {
e.printStackTrace();
}
}
}
/ * 運行結果 */
jsonGenerator
{“name”:”name1”,”age”:1,”sex”:”man”}
[{“name”:”name1”,”age”:1,”sex”:”man”},{“name”:”name2”,”age”:2,”sex”:”man”}]
ObjectMapper
[{“name”:”name1”,”age”:1,”sex”:”man”},{“name”:”name2”,”age”:2,”sex”:”man”}]