Mybatis inserting a record returns a primary key

Insert a record return primary key Scenario:Inserting a piece of data into the database requires that the ID primary key that returns the inserted data must be integer and supports the self-increment requirement implementation: Execute SELECT LAST_INSERT_ID () after saving is complete Entity Design

public class User implements Serializable {private Integer ID;
    private String name;
    private String password;
    Private Float salary;

    Private Date birthday;
    Public String GetPassword () {return password;
    } public void SetPassword (String password) {this.password = password;
    } public Integer GetId () {return id;
    } public void SetId (Integer id) {this.id = ID;
    } public String GetName () {return name;
    } public void SetName (String name) {this.name = name;
    } public Float Getsalary () {return salary;
    } public void Setsalary (Float salary) {this.salary = salary;
    Public Date Getbirthday () {return birthday;
    } public void Setbirthday (Date birthday) {this.birthday = birthday;
        } @Override public boolean equals (Object o) {if (this = = O) return true; if (o = = NULL | | getclass ()! = O.getclass ()) return false;
        User user = (user) O; return objects.equals (ID, user.id) && objects.equals (name, user.name) && O
    Bjects.equals (Salary, User.salary) && objects.equals (Birthday, user.birthday);
    } @Override public int hashcode () {return Objects.hash (ID, name, salary, birthday); } @Override Public String toString () {return "user{" + "id=" + ID + ", n
                Ame= ' + name + ' \ ' + ', password= ' + password + ' \ ' + ', salary= ' + salary +
    ", birthday=" + Birthday + '} '; }
}

Mapper Interface

void Saveuser (user user);

Note: The requirement for each insertion needs to return the ID of the data, and when the data is inserted, the ID property of the current object will have a value; interface design does not require a return value
Mapper Mapping File

<?xml version= "1.0" encoding= "UTF-8"?> <!
DOCTYPE Mapper Public
        "-//mybatis.org//dtd mapper 3.0//en"
        "HTTP://MYBATIS.ORG/DTD/MYBATIS-3-MAPPER.DTD" >
<mapper namespace= "Com.bjlemon.mybatis.mapper.UserMapper" >
    <cache type= " Org.mybatis.caches.ehcache.EhcacheCache "/>
     <insert id=" Saveuser "  parametertype=" User ">
         <selectkey keyproperty= "id"  resulttype= "int" order= "after" >
         select last_insert_id ();
      </selectKey>
         INSERT into
                mybatis_in_action_user (name,password,salary,birthday)
         VALUES
                (#{name},#{password},#{salary},#{birthday})
     </insert>

</mapper>

implemented in Orcal

<insert parametertype= "User" id= "Saveuser" >

<selectkey order= "before" resulttype= "int" keyproperty= "id "> select Seq_mybatis_user.nextval from Dual </selectKey>
INSERT into Mybatis_user (User_id,user_name, Password, salary, birthday) VALUES (#{id}, #{name},#{password},#{salary},#{birthday}) 
</insert>

Service Layer

  void AddUser (user user);

  @Override public
    void AddUser (user user) {
        sqlsession sqlsession = null;

        try {
            sqlsession = mybatisutils.getsqlsession ();
            Usermapper mapper = Sqlsession.getmapper (usermapper.class);
            if (user = = null) {
                throw  new IllegalArgumentException ();
            }
            Mapper.saveuser (user);
            Sqlsession.commit ();
        } catch (Exception e) {
            e.printstacktrace ();
            Sqlsession.rollback ();
        } finally {
            mybatisutils.clolsesqlsession ();
        }

    }

test Method

 @Before public void before () {this.userservice = new Userserviceimpl ();
         } @Test public void Saveuser () {User user = new User ();
         User.setname ("small ad");
         User.setpassword ("12312");
         User.setsalary (121.0F);
        User.setbirthday (New Date ());
        This.userService.addUser (user);
    When the object is inserted, the user of the object will have the value System.out.println (User.getid ()); }