fastjson 学习总结

1.pom.xml里引入jar包

<!-- 阿里巴巴高性能json开发包 -->
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>fastjson</artifactId>
<version>1.2.3</version>
</dependency>

2.新建一个User类

public class User {
private Long id;
private String name;

public Long getId() { return id; }
public void setId(Long id) { this.id = id; }

public String getName() { return name; }
public void setName(String name) { this.name = name; }
}

3.新建一个Group类

public class Group {
private Long id;
private String name;
private List<User> users = new ArrayList<User>();

public Long getId() { return id; }
public void setId(Long id) { this.id = id; }

public String getName() { return name; }
public void setName(String name) { this.name = name; }

public List<User> getUsers() { return users; }
public void setUsers(List<User> users) { this.users = users; }
}

4. 编写测试类

public class Main {

public static void main(String[] args) {
Group group = new Group();
group.setId(0L);
group.setName("admin");

User guestUser = new User();
guestUser.setId(2L);
guestUser.setName("guest");

User rootUser = new User();
rootUser.setId(3L);
rootUser.setName("root");

group.getUsers().add(guestUser);
group.getUsers().add(rootUser);

String jsonString = JSON.toJSONString(group);

System.out.println(jsonString);

Group group2 = JSON.parseObject(jsonString, Group.class);
System.out.println(group2.getName());

String jsonStr = "{\"name\":\"兰溪小城\",\"sex\":\"1\",\"mobile\":\"1234567890\"}" ;
JSONObject jsonObject = JSONObject.parseObject(jsonStr) ;
System.out.println(jsonObject.get("name"));

String jsonStr1 = "[{\"name\":\"兰溪小城\",\"sex\":\"1\",\"mobile\":\"1234567890\"}]" ;
JSONArray jsonArray = JSONArray.parseArray(jsonStr1);
System.out.println(jsonArray.get(0));
}

}

5. fastjson 解析json字符串为四种类型

(1) JavaBean
Person person = JSON.parseObject(jsonString, Person.class);

(2) List<JavaBean>
List<Person> listPerson =JSON.parseArray(jsonString, Person.class);

(3) List<String>
List<String> listString = JSON.parseArray(jsonString, String.class);

(4) List<Map<String,Object>>
List<Map<String, Object>> listMap = JSON.parseObject(jsonString, new TypeReference<List<Map<String,Object>>>(){});