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    云原生多模数据库 Lindorm：基于Java ORM框架MyBatis的应用开发

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    云原生多模数据库 Lindorm：基于Java ORM框架MyBatis的应用开发

    更新时间：Jun 05, 2024

    Lindorm宽表引擎提供了一系列基于MySQL协议的连接方式，涉及多种语言和多种框架，其中包括Java对象关系映射（ORM）框架MyBatis。MyBatis框架实现了SQL与代码的解耦，使数据管理变得更加灵活和方便。如果您习惯使用MyBatis框架进行数据开发，或想要对SQL语句进行统一管理和优化，推荐您通过Java ORM框架MyBatis连接和使用Lindorm宽表引擎。

    前提条件

    • 已开通MySQL协议兼容功能。如何开通，请参见开通MySQL协议兼容功能。

    • 已安装Java环境，要求安装JDK 1.8及以上版本。

    • 已将客户端IP添加至白名单，具体操作请参见设置白名单。

    操作步骤

    1. 添加MyBatis和MySQL JDBC Driver依赖。以Maven项目为例，在pom.xml文件的dependencies中添加以下依赖项：

      <dependency>
    <groupId>org.mybatis</groupId>
    <artifactId>mybatis</artifactId>
    <version>3.5.14</version>
</dependency>
<dependency>
    <groupId>com.mysql</groupId>
    <artifactId>mysql-connector-j</artifactId>
    <version>8.0.33</version>
</dependency>

    2. 在resources目录下，创建mybatis-config.xml基础配置文件，用于保存Lindorm宽表引擎相关连接信息。

      <?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "https://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC"/>
            <dataSource type="POOLED">
                <property name="driver" value="com.mysql.cj.jdbc.Driver"/>
                <property name="url" value="jdbc:mysql://ld-uf6k8yqb741t3****-proxy-sql-lindorm-public.lindorm.rds.aliyuncs.com:33060/default"/>
                <property name="username" value="root"/>
                <property name="password" value="test"/>
            </dataSource>
        </environment>
    </environments>
    <mappers>
        <mapper class="org.example.UserMapper"/>
    </mappers>
</configuration>

      参数说明

      参数

      说明

      url

      MySQL协议的Java JDBC连接地址及需要连接的数据库。格式为jdbc:mysql://<MySQL兼容地址>/<数据库名>。默认连接default数据库。

      如何获取MySQL兼容地址，请参见查看连接地址。

      重要

      • 如果应用部署在ECS实例，建议您通过专有网络访问Lindorm实例，可获得更高的安全性和更低的网络延迟。

      • 如果应用部署在本地，在通过公网连接Lindorm实例前，需在控制台开通公网地址。开通方式：在控制台选择数据库连接 > 宽表引擎，在宽表引擎页签单击开通公网地址。

      • 通过专有网络访问Lindorm实例，url中请填写MySQL兼容地址对应的专有网络地址。通过公网访问Lindorm实例，url中请填写MySQL兼容地址对应的公网地址。

      username

      如果您忘记用户密码，可以通过Lindorm宽表引擎的集群管理系统修改密码。具体操作，请参见修改用户密码。

      password

    3. 创建对象类。

      package org.example;

import java.nio.charset.StandardCharsets;
import java.sql.Date;
import java.sql.Timestamp;

public class User {
  private int userId;
  private String userName;
  private double height;
  private long score;
  private Timestamp createTime;
  private Date birthday;

  private byte[] digest;

  public User(int userId, String userName, double height, long score,
      Timestamp createTime, Date birthday, byte[] digest) {
    this.userId = userId;
    this.userName = userName;
    this.height = height;
    this.score = score;
    this.createTime = createTime;
    this.birthday = birthday;
    this.digest = digest;
  }

  public int getUserId() {
    return userId;
  }

  public void setUserId(int userId) {
    this.userId = userId;
  }

  public String getUserName() {
    return userName;
  }

  public void setUserName(String userName) {
    this.userName = userName;
  }

  public double getHeight() {
    return height;
  }

  public void setHeight(double height) {
    this.height = height;
  }

  public long getScore() {
    return score;
  }

  public void setScore(long score) {
    this.score = score;
  }

  public Timestamp getCreateTime() {
    return createTime;
  }

  public void setCreateTime(Timestamp createTime) {
    this.createTime = createTime;
  }

  public Date getBirthday() {
    return birthday;
  }

  public void setBirthday(Date birthday) {
    this.birthday = birthday;
  }

  public byte[] getDigest() {
    return digest;
  }

  public void setDigest(byte[] digest) {
    this.digest = digest;
  }

  @Override
  public String toString() {
    return "User{" + "userId=" + userId + ", userName='" + userName + '\'' + ", height=" + height + ", score=" + score + ", createTime=" + createTime + ", birthday=" + birthday + ", digest=" + new String(digest, StandardCharsets.UTF_8) + '}';
  }
}

    4. 创建MyBatis框架的Mapper，用于定义SQL语句与业务代码的映射关系。

      import org.apache.ibatis.annotations.Delete;
import org.apache.ibatis.annotations.Insert;
import org.apache.ibatis.annotations.Param;
import org.apache.ibatis.annotations.Select;
import org.apache.ibatis.annotations.Update;

package org.example;

import java.util.List;

public interface UserMapper {

  @Update("create table if not exists demo_user(`id` INT, `name` VARCHAR, `height` DOUBLE, `score` BIGINT, `createtime` TIMESTAMP, `birthday` DATE, digest VARBINARY,primary key(id))")
  void createUserTable();

  @Update("drop table if exists demo_user")
  void dropUserTable();

  @Insert("upsert into demo_user(`id`,`name`,`height`,`score`,`createtime`,`birthday`,`digest`) values(#{userId},#{userName},#{height},#{score},#{createTime},#{birthday},#{digest})")
  int upsertUser(User user);

  @Delete("delete from demo_user where `id` = #{userId}")
  int deleteUser(@Param("userId") int userId);

  @Select("select * from demo_user where `id` = #{userId}")
  User selectOneUser(@Param("userId") int userId);

  @Select("select * from demo_user")
  List<User> selectAllUser();
}

    5. 编写业务代码。

      package org.example;

import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;

import java.io.InputStream;
import java.nio.charset.StandardCharsets;
import java.sql.Date;
import java.sql.Timestamp;

public class MybatisDemo {
  public static void main(String[] args) throws Exception {
    String resource = "mybatis-config.xml";
    InputStream inputStream = Resources.getResourceAsStream(resource);
    SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(
        inputStream);
    try (SqlSession session = sqlSessionFactory.openSession()) {
      UserMapper mapper = session.getMapper(UserMapper.class);

      //create user table
      mapper.createUserTable();

      //select all users
      System.out.println(mapper.selectAllUser());

      User user1 = new User(1, "zhangsan", 1.8, 100,
          new Timestamp(System.currentTimeMillis()),
          Date.valueOf("1995-03-02"),
          "hello".getBytes(StandardCharsets.UTF_8));
      User user2 = new User(2, "lisi", 1.7, 90,
          new Timestamp(System.currentTimeMillis()),
          Date.valueOf("1996-08-02"),
          "world".getBytes(StandardCharsets.UTF_8));

      //insert user1 and user2
      mapper.upsertUser(user1);
      mapper.upsertUser(user2);

      //select all users
      System.out.println(mapper.selectAllUser());
      //select user1
      System.out.println(mapper.selectOneUser(1));

      //delete user1
      mapper.deleteUser(1);
      System.out.println(mapper.selectAllUser());

      //update user2's score to 99
      user2.setScore(99);
      mapper.upsertUser(user2);
      System.out.println(mapper.selectAllUser());

      //drop user table
      mapper.dropUserTable();
    }
  }
}

    完整示例

    完整示例代码，请参见mybatis-demo.tar。

    执行成功后，将返回以下结果：

    [User{userId=1, userName='zhangsan', height=1.8, score=100, createTime=2023-12-02 09:39:17.63, birthday=1995-03-02, digest=hello}, User{userId=2, userName='lisi', height=1.7, score=90, createTime=2023-12-02 09:39:17.63, birthday=1996-08-02, digest=world}]
User{userId=1, userName='zhangsan', height=1.8, score=100, createTime=2023-12-02 09:39:17.63, birthday=1995-03-02, digest=hello}
[User{userId=2, userName='lisi', height=1.7, score=90, createTime=2023-12-02 09:39:17.63, birthday=1996-08-02, digest=world}]
[User{userId=2, userName='lisi', height=1.7, score=99, createTime=2023-12-02 09:39:17.63, birthday=1996-08-02, digest=world}]