实体类

User

import org.msgpack.annotation.Message;
@Message
public class User {
    private String id;
    private String userName;
    private int age;
    private UserContact userContact;
    public User(String userName, int age, String id) {
        this.userName = userName;
        this.age = age;
        this.id = id;
    }
    public User() {
    }
    public String getUserName() {
        return userName;
    }
    public void setUserName(String userName) {
        this.userName = userName;
    }
    public int getAge() {
        return age;
    }
    public void setAge(int age) {
        this.age = age;
    }
    public String getId() {
        return id;
    }
    public void setId(String id) {
        this.id = id;
    }
    public UserContact getUserContact() {
        return userContact;
    }
    public void setUserContact(UserContact userContact) {
        this.userContact = userContact;
    }
    @Override
    public String toString() {
        return "User{" +
                "userName='" + userName + '\'' +
                ", age=" + age +
                ", id='" + id + '\'' +
                ", userContact=" + userContact +
                '}';
    }
}

UserContact

import org.msgpack.annotation.Message;
@Message//MessagePack提供的注解，表明这是一个需要序列化的实体类
public class UserContact {
    private String mail;
    private String phone;
    public UserContact() {
    }
    public UserContact(String mail, String phone) {
        this.mail = mail;
        this.phone = phone;
    }
    public String getMail() {
        return mail;
    }
    public void setMail(String mail) {
        this.mail = mail;
    }
    public String getPhone() {
        return phone;
    }
    public void setPhone(String phone) {
        this.phone = phone;
    }
    @Override
    public String toString() {
        return "UserContact{" +
                "mail='" + mail + '\'' +
                ", phone='" + phone + '\'' +
                '}';
    }
}