fastjson-解析json
阿新 • • 發佈:2019-01-06
Fastjson:
https://github.com/alibaba/fastjson
star數:12K
阿里巴巴FastJson是一個Json處理工具包,包括“序列化”和“反序列化”兩部分,它具備如下特徵:
速度最快,測試表明,fastjson具有極快的效能,超越任其他的Java Json parser。包括自稱最快的JackJson;
功能強大,完全支援Java Bean、集合、Map、日期、Enum,支援範型,支援自省;無依賴,能夠直接執行在Java SE 5.0以上版本;支援Android;開源 (Apache 2.0)
使用:
String text = JSON.toJSONString(obj); //序列化
VO vo = JSON.parseObject("{...}", VO.class); //反序列化
示例:
實體類:
package com.json.bean;
public class Person {
private String id ;
private String name;
private int age ;
public Person(){
}
public Person(String id,String name,int age){
this.id=id;
this.name=name;
this .age=age;
}
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
@Override
public String toString() {
return "解析json字串後獲取的person物件:id的值是" +
id + ", name的值是" + name + ", age的值是" + age + "";
}
}
轉化類:
package com.json.fastjson;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.TypeReference;
import com.json.bean.Person;
/*
* 這裡將json的轉化和解析都放在一起了,大家可以根據實際需要來轉化json字串和解析json字串
*/
public class FastjsonClass {
public static void main(String[] args) {
method1();
method2();
method3();
method4();
}
static void method1(){
System.out.println("javabean轉化示例開始----------");
Person person = new Person("1","fastjson",1);
//這裡將javabean轉化成json字串
String jsonString = JSON.toJSONString(person);
System.out.println(jsonString);
//這裡將json字串轉化成javabean物件,
person =JSON.parseObject(jsonString,Person.class);
System.out.println(person.toString());
System.out.println("javabean轉化示例結束----------");
}
static void method2(){
System.out.println("List<javabean>轉化示例開始----------");
Person person1 = new Person("1","fastjson1",1);
Person person2 = new Person("2","fastjson2",2);
List<Person> persons = new ArrayList<Person>();
persons.add(person1);
persons.add(person2);
String jsonString = JSON.toJSONString(persons);
System.out.println("json字串:"+jsonString);
//解析json字串
List<Person> persons2 = JSON.parseArray(jsonString,Person.class);
//輸出解析後的person物件,也可以通過除錯模式檢視persons2的結構
System.out.println("person1物件:"+persons2.get(0).toString());
System.out.println("person2物件:"+persons2.get(1).toString());
System.out.println("List<javabean>轉化示例結束----------");
}
static void method3(){
System.out.println("List<String>轉化示例開始----------");
List<String> list = new ArrayList<String>();
list.add("fastjson1");
list.add("fastjson2");
list.add("fastjson3");
String jsonString = JSON.toJSONString(list);
System.out.println("json字串:"+jsonString);
//解析json字串
List<String> list2 = JSON.parseObject(jsonString,new TypeReference<List<String>>(){});
System.out.println(list2.get(0)+"::"+list2.get(1)+"::"+list2.get(2));
System.out.println("List<String>轉化示例結束----------");
}
static void method4(){
System.out.println(" List<Map<String,Object>>轉化示例開始 ----------");
Map<String,Object> map = new HashMap<String,Object>();
map.put("key1", "value1");
map.put("key2", "value2");
Map<String,Object> map2 = new HashMap<String,Object>();
map2.put("key1", 1);
map2.put("key2", 2);
List<Map<String,Object>> list = new ArrayList<Map<String,Object>>();
list.add(map);
list.add(map2);
String jsonString = JSON.toJSONString(list);
System.out.println("json字串:"+jsonString);
//解析json字串
List<Map<String,Object>> list2 = JSON.parseObject(jsonString,new TypeReference<List<Map<String,Object>>>(){});
System.out.println("map的key1值"+list2.get(0).get("key1"));
System.out.println("map的key2值"+list2.get(0).get("key2"));
System.out.println("ma2p的key1值"+list2.get(1).get("key1"));
System.out.println("map2的key2值"+list2.get(1).get("key2"));
}
}