fastjson解析

听闻阿里的fastJson特别的厉害.就下载了,稍微的试了一下:

本次使用:fastjson-1.2.8.jar

本次只是比较简单的对象和json之间的转换,没有涉及到复杂对象与json之间的转换.

有两个实体类,User和GroupBean,本次暂时只是涉及到User类

public class User {

private String id;

private String name;

private Integer age;

补充set和get方法}

public class GroupBean {

private String id;

private List list=new ArrayList();

private Set  set=new HashSet();

private Map map=new HashMap();

补充set和get方法}

import org.junit.Test;

import com.alibaba.fastjson.JSON;

import com.alibaba.fastjson.JSONArray;

import com.alibaba.fastjson.JSONObject;

import com.alibaba.fastjson.TypeReference;

import com.alibaba.fastjson.parser.Feature;

public class MyTest {

//简单对象的转换

@Test

public void test1() {

User user1 = new User("1","caocao",20);

User user2 = new User("2","liubei",22);

List list=new ArrayList();

Set  set=new HashSet();

Map map=new HashMap();

list.add(user1);

list.add(user2);

set.add(user1);

set.add(user2);

map.put("user1", user1);

map.put("user2", user2);

//把对象转换成json

String jsonString1 = JSON.toJSONString(user1);

String jsonString2= JSON.toJSONString(user2);

System.out.println(jsonString1);  //打印转换成json的字符串

//{"age":20,"id":"1","name":"caocao"}

System.out.println(user1);  //直接打印对象

//User [id=1, name=caocao, age=20]

System.out.println(jsonString2);

//{"age":22,"id":"2","name":"liubei"}

System.out.println(user2);

//User [id=2, name=liubei, age=22]

String jsonString3 = JSON.toJSONString(list);

System.out.println(jsonString3);

//[{"age":20,"id":"1","name":"caocao"},{"age":22,"id":"2","name":"liubei"}]

String jsonString4 = JSON.toJSONString(set);

System.out.println(jsonString4);

//[{"age":20,"id":"1","name":"caocao"},{"age":22,"id":"2","name":"liubei"}]

String jsonString5 = JSON.toJSONString(map);

System.out.println(jsonString5);

//{"user2":{"age":22,"id":"2","name":"liubei"},"user1":{"age":20,"id":"1","name":"caocao"}}

//把json转换成bean

Object parse1 = JSON.parse(jsonString1);  //直接进行解析

System.out.println(parse1);

//{"id":"1","name":"caocao","age":20}

//强转类型,不能进行强制类型的转换,会报出类转换异常的

//User parse2=(User)parse1;

User parseObject = JSON.parseObject(jsonString2, User.class);  //添加类进行解析,直接得到bean

System.out.println(parseObject+"~~"+parseObject.getName());

//User [id=2, name=liubei, age=22]~~liubei

//直接解析出报错

//    JSONObject parseObject2 = JSON.parseObject(jsonString3);

//添加类型解析

List parseObject2 = JSON.parseObject(jsonString3, new TypeReference>() {});

System.out.println(parseObject2);

//[User [id=1, name=caocao, age=20], User [id=2, name=liubei, age=22]]

//按照数据的类型解析

JSONArray parseArray = JSON.parseArray(jsonString3);

System.out.println(parseArray);

//[{"id":"1","name":"caocao","age":20},{"id":"2","name":"liubei","age":22}]

//解析出具体的map类型

Map parseObject5 = JSON.parseObject(jsonString5, new TypeReference>(){});

System.out.println(parseObject5);

//{user2=User [id=2, name=liubei, age=22], user1=User [id=1, name=caocao, age=20]}

//粗略的解析出了map

Map parseObject6 = JSON.parseObject(jsonString5, Map.class);

System.out.println(parseObject6);

//{user2={"id":"2","name":"liubei","age":22}, user1={"id":"1","name":"caocao","age":20}}

}

}

本次博客就先到这里,再过段时间我会把复杂和json之间的解析发出来.

如果错误,敬请指正

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