fastjson使用

fastjson是阿里的json处理工具包，使用简单，具有极快的性能。
maven依赖如下：

 <dependency>      <groupId>com.alibaba</groupId>      <artifactId>fastjson</artifactId>      <version>1.2.35</version>    </dependency>

1.使用fastjson将java对象转换为json字符串

public class User {    private String name;    private String pass;    private String phone;    public String getName() {        return name;    }    public void setName(String name) {        this.name = name;    }    public String getPass() {        return pass;    }    public void setPass(String pass) {        this.pass = pass;    }    public String getPhone() {        return phone;    }    public void setPhone(String phone) {        this.phone = phone;    }}

public class TestDemo1 {    public static void main(String[] args) {        User user=new User();        user.setName("abc");        user.setPass("123");        user.setPhone("123456");      String json=  JSONObject.toJSONString(user);        System.out.println(json);    }}

结果如下：

{"name":"abc","pass":"123","phone":"123456"}

2.将json字符串转换为json对象并提取数据
下面是两层嵌套的json数据

{"name":"abc","pass":"123","phone":"123456","ability":{"java":"practised","python":"master"}}

对json解析，从json中提取数据

public class TestDemo2 {    public static void main(String[] args) {         //将json字符串转换为json对象        String json="{\"name\":\"abc\",\"pass\":\"123\",\"phone\":\"123456\",\"ability\":{\"java\":\"practised\",\"python\":\"master\"}}";          JSONObject jsonObject= JSON.parseObject(json);         //提取name的值          String name=jsonObject.get("name").toString();          System.out.println(name);         //提取内层的json串的值          Object o=jsonObject.get("ability");          System.out.println(o);         //内层的值单独看作一个json串          JSONObject j=JSON.parseObject(o.toString());          System.out.println(j.get("java"));    }}