1. 有如下json 数据，自己定义合适的java类,将json 转换成java 对象并打印 { "username": "zs", "age": 20, "userDetail": { "address": "北京朝阳", "havHouse": true, "havCar": true }, "contacts": [{ "phoneNumber": "110", "contactName": "小红" }, { "phoneNumber": "12323213", "contactName": "小明" } ] }

可以定义以下 Java 类来表示该 JSON 数据：

public class User {
    private String username;
    private int age;
    private UserDetail userDetail;
    private List<Contact> contacts;

    // getters and setters
}

public class UserDetail {
    private String address;
    private boolean havHouse;
    private boolean havCar;

    // getters and setters
}

public class Contact {
    private String phoneNumber;
    private String contactName;

    // getters and setters
}

然后可以使用 JSON 解析库（如 fastjson）将 JSON 数据转换为 Java 对象，示例代码如下：

String jsonStr = "{\"username\": \"zs\",\"age\": 20,\"userDetail\": {\"address\": \"北京朝阳\",\"havHouse\": true,\"havCar\": true},\"contacts\": [{\"phoneNumber\": \"110\",\"contactName\": \"小红\"},{\"phoneNumber\": \"12323213\",\"contactName\": \"小明\"}]}";

User user = JSON.parseObject(jsonStr, User.class);

System.out.println(user.getUsername());
System.out.println(user.getAge());
System.out.println(user.getUserDetail().getAddress());
System.out.println(user.getUserDetail().isHavHouse());
System.out.println(user.getUserDetail().isHavCar());
for (Contact contact : user.getContacts()) {
    System.out.println(contact.getPhoneNumber());
    System.out.println(contact.getContactName());
}

输出结果为：

zs
20
北京朝阳
true
true
110
小红
12323213
小明