SpringBoot2 | 第十篇：Mybatis代码生成器

SpringBoot 2.0 中如何使用代码生成器

[TOC]

环境/版本一览：

• 开发工具：Intellij IDEA 2018.2.2
• springboot： 2.0.5.RELEASE
• jdk：1.8.0_171
• maven：3.3.9
• generator：1.3.5

1、搭建

2、pom.xml

<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <dependency>
        <groupId>org.mybatis.spring.boot</groupId>
        <artifactId>mybatis-spring-boot-starter</artifactId>
        <version>1.3.2</version>
    </dependency>
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <scope>runtime</scope>
    </dependency>
    <dependency>
        <groupId>org.projectlombok</groupId>
        <artifactId>lombok</artifactId>
        <optional>true</optional>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
        <scope>test</scope>
    </dependency>
</dependencies>

<build>
    <plugins>
        <plugin>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-maven-plugin</artifactId>
        </plugin>
        <!-- mybatis generator 自动生成代码插件 -->
        <plugin>
            <groupId>org.mybatis.generator</groupId>
            <artifactId>mybatis-generator-maven-plugin</artifactId>
            <version>1.3.5</version>
            <configuration>
                <configurationFile>${basedir}/src/main/resources/generator/generatorConfig.xml</configurationFile>
                <overwrite>true</overwrite>
                <verbose>true</verbose>
            </configuration>
        </plugin>
    </plugins>
</build>

3、application.yml

server:
  port: 8080

spring:
  datasource:
    driver-class-name: com.mysql.jdbc.Driver
    # 基本属性  allowMultiQueries：设置为true后，数据库那边才允许你批量更新。编码属性设置了存储数据到数据库才不会是乱码
    url: jdbc:mysql://localhost:3306/chapter10?useUnicode=true&characterEncoding=UTF-8&allowMultiQueries=true&serverTimezone=UTC&useSSL=false
    username: root
    password: 123456
    # 下面为连接池的补充设置，应用到上面所有数据源中
    hikari:
      # 表示连接池的用户定义名称，主要显示在日志记录和JMX管理控制台中，以标识池和池配置。
      pool-name: HikariPool
      # 控制客户端（即您）等待池中连接的最大毫秒数。如果在没有连接可用的情况下超过此时间，则将抛出SQLException。最低可接受的连接超时为250毫秒。 默认值：30000（30秒）
      connection-timeout: 3000
      # 控制允许连接在池中空闲的最长时间。默认值：600000（10分钟）
      idle-timeout: 600000
      # 控制池中连接的最长生命周期。默认值：1800000（30分钟）
      max-lifetime: 1800000

mybatis:
  mapper-locations: classpath:mapper/*.xml  # 注意：一定要对应 mapper 映射xml文件的所在路径
  type-aliases-package: com.fatal.entity  # 注意：对应实体类的路径
  configuration:
    log-impl: org.apache.ibatis.logging.stdout.StdOutImpl  # 可以自控制台上输出 sql 语句

4、sql

CREATE TABLE `user`(
  `id` INT NOT NULL PRIMARY KEY AUTO_INCREMENT,
  `username` VARCHAR(255) NOT NULL ,
  `password` VARCHAR(255) NOT NULL ,
  `phone` VARCHAR(255) NOT NULL
) ENGINE=INNODB AUTO_INCREMENT=1000 DEFAULT CHARSET=utf8;

5、使用mybatis generator 自动生成代码

• 往项目中添加generatorConfig.xml 文件。可以把下面的配置复制下去改

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE generatorConfiguration
        PUBLIC "-//mybatis.org//DTD MyBatis Generator Configuration 1.0//EN"
        "http://mybatis.org/dtd/mybatis-generator-config_1_0.dtd">
<generatorConfiguration>
    <!-- 数据库驱动:选择你的本地硬盘上面的数据库驱动包-->
    <classPathEntry  location="E:\mysql\lib\mysql-connector-java-5.1.46.jar"/>
    <context id="DB2Tables"  targetRuntime="MyBatis3">
        <commentGenerator>
            <property name="suppressDate" value="true"/>
            <!-- 是否去除自动生成的注释 true：是 ： false:否 -->
            <property name="suppressAllComments" value="true"/>
        </commentGenerator>
        <!--数据库链接URL，用户名、密码 -->
        <jdbcConnection driverClass="com.mysql.jdbc.Driver"
                        connectionURL="jdbc:mysql://127.0.0.1/chapter10"
                        userId="root"
                        password="123456">
        </jdbcConnection>
        <javaTypeResolver>
            <property name="forceBigDecimals" value="false"/>
        </javaTypeResolver>
        <!-- 生成模型的包名和位置-->
        <javaModelGenerator targetPackage="com.fatal.entity" targetProject="src/main/java">
            <property name="enableSubPackages" value="true"/>
            <property name="trimStrings" value="true"/>
        </javaModelGenerator>
        <!-- 生成映射文件的包名和位置-->
        <sqlMapGenerator targetPackage="mapper" targetProject="src/main/resources">
            <property name="enableSubPackages" value="true"/>
        </sqlMapGenerator>
        <!-- 生成DAO的包名和位置-->
        <javaClientGenerator type="XMLMAPPER" targetPackage="com.fatal.mapper" targetProject="src/main/java">
            <property name="enableSubPackages" value="true"/>
        </javaClientGenerator>
        <!-- 要生成的表 tableName是数据库中的表名或视图名 domainObjectName是实体类名-->
        <table tableName="user" domainObjectName="User" enableCountByExample="false" enableUpdateByExample="false" enableDeleteByExample="false" enableSelectByExample="false" selectByExampleQueryId="false"></table>
    </context>
</generatorConfiguration>

注意：

1. 如果上面的 “http://mybatis.org/dtd/mybatis-generator-config_1_0.dtd" 报红线

解决方式如下：FIle->Setting->Languages&Frameworks->Schemas and DTDs

2. mysql jar 包可以去 maven 仓库取，所以在配置文件中的路径你可以直接给 maven仓库 对应版本 jar包 的路径。

• 点击run-Edit Configurations

• 添加配置

  

• 运行

注意！！！同一张表一定不要运行多次，因为mapper的映射文件中会生成多次的代码，导致报错，==切记==

最后生成的文件以及结构：

6、生成的文件

User.java

我用 @Data 方法把生成的 getset 替代了

package com.fatal.entity;

import lombok.Data;
import lombok.experimental.Accessors;

@Data
@Accessors(chain = true)
public class User {

    private Integer id;

    private String username;

    private String password;

    private String phone;

}

UserMapper.java

package com.fatal.mapper;

import com.fatal.entity.User;

public interface UserMapper {
    int deleteByPrimaryKey(Integer id);

    int insert(User record);

    int insertSelective(User record);

    User selectByPrimaryKey(Integer id);

    int updateByPrimaryKeySelective(User record);

    int updateByPrimaryKey(User record);
}

UserMapper.xml

<?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.fatal.mapper.UserMapper">
  <resultMap id="BaseResultMap" type="com.fatal.entity.User">
    <id column="id" jdbcType="INTEGER" property="id" />
    <result column="username" jdbcType="VARCHAR" property="username" />
    <result column="password" jdbcType="VARCHAR" property="password" />
    <result column="phone" jdbcType="VARCHAR" property="phone" />
  </resultMap>
  <sql id="Base_Column_List">
    id, username, password, phone
  </sql>
  <select id="selectByPrimaryKey" parameterType="java.lang.Integer" resultMap="BaseResultMap">
    select 
    <include refid="Base_Column_List" />
    from user
    where id = #{id,jdbcType=INTEGER}
  </select>
  <delete id="deleteByPrimaryKey" parameterType="java.lang.Integer">
    delete from user
    where id = #{id,jdbcType=INTEGER}
  </delete>
  <insert id="insert" parameterType="com.fatal.entity.User">
    insert into user (id, username, password, 
      phone)
    values (#{id,jdbcType=INTEGER}, #{username,jdbcType=VARCHAR}, #{password,jdbcType=VARCHAR}, 
      #{phone,jdbcType=VARCHAR})
  </insert>
  <insert id="insertSelective" parameterType="com.fatal.entity.User">
    insert into user
    <trim prefix="(" suffix=")" suffixOverrides=",">
      <if test="id != null">
        id,
      </if>
      <if test="username != null">
        username,
      </if>
      <if test="password != null">
        password,
      </if>
      <if test="phone != null">
        phone,
      </if>
    </trim>
    <trim prefix="values (" suffix=")" suffixOverrides=",">
      <if test="id != null">
        #{id,jdbcType=INTEGER},
      </if>
      <if test="username != null">
        #{username,jdbcType=VARCHAR},
      </if>
      <if test="password != null">
        #{password,jdbcType=VARCHAR},
      </if>
      <if test="phone != null">
        #{phone,jdbcType=VARCHAR},
      </if>
    </trim>
  </insert>
  <update id="updateByPrimaryKeySelective" parameterType="com.fatal.entity.User">
    update user
    <set>
      <if test="username != null">
        username = #{username,jdbcType=VARCHAR},
      </if>
      <if test="password != null">
        password = #{password,jdbcType=VARCHAR},
      </if>
      <if test="phone != null">
        phone = #{phone,jdbcType=VARCHAR},
      </if>
    </set>
    where id = #{id,jdbcType=INTEGER}
  </update>
  <update id="updateByPrimaryKey" parameterType="com.fatal.entity.User">
    update user
    set username = #{username,jdbcType=VARCHAR},
      password = #{password,jdbcType=VARCHAR},
      phone = #{phone,jdbcType=VARCHAR}
    where id = #{id,jdbcType=INTEGER}
  </update>
</mapper>

7、启动类添加Mapper扫描

package com.fatal;

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
@MapperScan("com.fatal.mapper")
public class Chapter10Application {

    public static void main(String[] args) {
        SpringApplication.run(Chapter10Application.class, args);
    }
}

8、Test

package com.fatal.mapper;

import com.fatal.entity.User;
import org.junit.Assert;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;

/**
 * @author: Fatal
 * @date: 2018/10/5 0005 16:09
 */
@SpringBootTest
@RunWith(SpringRunner.class)
public class UserMapperTest {

    @Autowired
    private UserMapper mapper;

    @Test
    public void deleteByPrimaryKey() {
        int record = mapper.deleteByPrimaryKey(1001);
        Assert.assertNotEquals(0, record);
    }

    @Test
    public void insert() {
        User user = new User().setUsername("米彩").setPassword("123").setPhone("123");
        int record = mapper.insert(user);
        Assert.assertNotEquals(0, record);
    }

    @Test
    public void insertSelective() {
        User user = new User().setUsername("米彩").setPassword("123");
        int record = mapper.insert(user);
        Assert.assertNotEquals(0, record);
    }

    /**
     * select id, user_name, password, phone from user where id = ?
     */
    @Test
    public void selectByPrimaryKey() {
        User user = mapper.selectByPrimaryKey(1000);
        Assert.assertNotEquals(null, user);
    }

    /**
     * Preparing: update user SET user_name = ?, password = ? where id = ?
     * Parameters: 米彩的姐姐(String), 123(String), 1000(Integer)
     */
    @Test
    public void updateByPrimaryKeySelective() {
        User user = new User().setId(1000).setUsername("米彩的姐姐").setPassword("123");
        int record = mapper.updateByPrimaryKeySelective(user);
        Assert.assertNotEquals(0, record);
    }

    /**
     * Preparing: update user set user_name = ?, password = ?, phone = ? where id = ?
     * Parameters: 米彩的姐姐(String), 123(String), null, 1000(Integer)
     */
    @Test
    public void updateByPrimaryKey() {
        User user = new User().setId(1000).setUsername("米彩的姐姐").setPassword("123");
        int record = mapper.updateByPrimaryKey(user);
        Assert.assertNotEquals(0, record);
    }
}

总结

SpringBoot的知识已经有前辈在我们之前探索了。比较喜欢的博主有：唐亚峰 | Battcn、方志朋的专栏、程序猿DD、纯洁的微笑。对这门技术感兴趣的可以去他们的博客逛逛。谢谢他们的分享~~

以上文章是我用来学习的Demo，都是基于 SpringBoot2.x 版本。

源码地址: https://github.com/ynfatal/springboot2-learning/tree/master/chapter10

学习 LuisChen 前辈的经验