【Java从零到架构师第③季】【43】SpringBoot-MyBatis

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【Java从零到架构师第③季】【43】SpringBoot-MyBatis

• • 引入依赖
  • 数据源配置
  • MyBatis配置
  • 扫描DAO
  • MyBatis主配置—XML
  • MyBatis主配置—注解
  • MyBatis主配置—application.yml
  • starter的命名规范
  • useGeneratedKeys
  • 实例
  • • • 项目结构
      • Application
      • MyBatisConfig
      • application.yml 与 MyBatis映射文件
      • mybatis-config.xml
      • index.html
      • controller
      • service
      • dao
  • 参考

引入依赖

http://mybatis.org/spring-boot-starter/mybatis-spring-boot-autoconfigure/

    <dependencies>
        <dependency>
            <groupId>org.mybatis.spring.bootgroupId>
            <artifactId>mybatis-spring-boot-starterartifactId>
            <version>2.1.3version>
        dependency>
        <dependency>
            <groupId>mysqlgroupId>
            <artifactId>mysql-connector-javaartifactId>
        dependency>
        <dependency>
            <groupId>com.alibabagroupId>
            <artifactId>druid-spring-boot-starterartifactId>
            <version>1.2.1version>
        dependency>

		
        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-thymeleafartifactId>
        dependency>
    dependencies>

数据源配置

spring:
  datasource:
    type: com.alibaba.druid.pool.DruidDataSource
    driver-class-name: com.mysql.cj.jdbc.Driver
    username: root
    password: root
    url: jdbc:mysql://localhost:3306/test_mybatis?serverTimezone=UTC
    druid:
      initial-size: 5
      max-active: 10

MyBatis配置

扫描DAO

MyBatis主配置—XML

mybatis:
  config-location: classpath:mybatis-config.xml

DOCTYPE configuration
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
    <settings>
        
        <setting name="mapUnderscoreToCamelCase" value="true"/>
    settings>
configuration>

MyBatis主配置—注解

@Configuration
public class MyBatisConfig {
    @Bean
    public ConfigurationCustomizer customizer() {
        return (configuration) -> {
            configuration.setMapUnderscoreToCamelCase(true);
        };
    }
}

MyBatis主配置—application.yml

mybatis:
  configuration:
    map-underscore-to-camel-case: true

starter的命名规范

https://docs.spring.io/spring-boot/docs/current/reference/html/using-spring-boot.html#using-boot-starter

useGeneratedKeys

useGeneratedKeys直接写在映射文件中：

DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="programmer.lp.dao.SkillDao">
    <insert id="save" parameterType="Skill"
            useGeneratedKeys="true"
            keyProperty="id">
        INSERT INTO skill(name, level) VALUES (#{name}, #{level})
    insert>
mapper>

实例 项目结构

Application

@SpringBootApplication
@MapperScan("programmer.lp.dao")
public class Application {
    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }
}

MyBatisConfig

@Configuration
public class MyBatisConfig {
    @Bean
    public ConfigurationCustomizer customizer() {
        return (configuration) -> {
            configuration.setMapUnderscoreToCamelCase(true);
            configuration.setUseGeneratedKeys(true);
        };
    }
}

application.yml 与 MyBatis映射文件

server:
  servlet:
    context-path: /mybatis
spring:
  datasource:
    type: com.alibaba.druid.pool.DruidDataSource
    driver-class-name: com.mysql.cj.jdbc.Driver
    username: root
    password: root
    url: jdbc:mysql://localhost:3306/test_mybatis?serverTimezone=UTC
    druid:
      initial-size: 5
      max-active: 10
mybatis:
  type-aliases-package: programmer.lp.domain
  #  mapper-locations: classpath:mappers/*.xml
  #  config-location: classpath:mybatis-config.xml
  configuration:
    map-underscore-to-camel-case: true
    use-generated-keys: true

或者直接将MyBatis-Mapper文件放到与dao相同的目录下：

方法一：

方法二：

pom.xml：

    <build>
        <resources>
            <resource>
                <directory>src/main/resourcesdirectory>
            resource>
            <resource>
                <directory>src/main/javadirectory>
                <includes>
                    <include>**/*.propertiesinclude>
                    <include>**/*.xmlinclude>
                    
                    
                    
                includes>
            resource>
        resources>
    build>

mybatis-config.xml

DOCTYPE configuration
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
    
    <settings>
        
        <setting name="useGeneratedKeys" value="true"/>
        
        <setting name="mapUnderscoreToCamelCase" value="true"/>
    settings>
configuration>

index.html

DOCTYPE html>
<html lang="zh" xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8">
    <title>Skilltitle>
head>
<body>

<div>
    <a th:href="@{/skills/get(id=1)}" target="_blank">单个a>
div>

<div>
    <a th:href="@{/skills/list}" target="_blank">列表a>
div>

<div>
    保存
    <form th:action="@{/skills/save}" method="post">
        <input name="id" placeholder="id">
        <input name="name" placeholder="name">
        <input name="level" placeholder="level">
        <button type="submit">保存button>
    form>
div>

<div>
    删除
    <form th:action="@{/skills/remove}" method="post">
        <input name="id" placeholder="id">
        <button type="submit">删除button>
    form>
div>

body>
html>

controller

@RestController
@RequestMapping("/skills")
public class SkillController {
    @Autowired
    private SkillService service;

    @GetMapping("/list")
    public List<Skill> list() {
        return service.list();
    }

    @GetMapping("/get")
    public Skill get(Integer id) {
        return service.get(id);
    }

    @PostMapping("/save")
    public String save(Skill skill) {
        String[] msgs;
        Integer id = skill.getId();
        if (id != null && id > 0) {
            msgs = new String[] {"更新成功", "更新失败"};
        } else {
            msgs = new String[] {"添加成功", "添加失败"};
        }
        return service.save(skill) ? msgs[0] + "_" + skill.getId() : msgs[1];
    }

    @PostMapping("/remove")
    public String remove(Integer id) {
        return service.remove(id) ? "删除成功" : "删除失败";
    }
}

service

@Service
@Transactional
public class SkillServiceImpl implements SkillService {
    @Autowired
    private SkillDao dao;

    @Override
    public boolean save(Skill skill) {
        System.out.println(skill.getId());
        Integer id = skill.getId();
        if (id == null || id < 1) {
            return dao.save(skill);
        }
        return dao.update(skill);
    }

    @Override
    @Transactional(readOnly = true)
    public List<Skill> list() {
        return dao.list();
    }

    @Override
    @Transactional(readOnly = true)
    public Skill get(Integer id) {
        return dao.get(id);
    }

    @Override
    public boolean remove(Integer id) {
        return dao.remove(id);
    }
}

public interface SkillService {
    boolean save(Skill skill);
    List<Skill> list();
    Skill get(Integer id);
    boolean remove(Integer id);
}

dao

public interface SkillDao {
    boolean save(Skill skill);
    boolean update(Skill skill);
    boolean remove(Integer id);
    @Select("SELECT * FROM skill")
    List<Skill> list();
    @Select("SELECT * FROM skill WHERE id = #{id}")
    Skill get(Integer id);
}

DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="programmer.lp.dao.SkillDao">
    <insert id="save" parameterType="Skill"
            useGeneratedKeys="true"
            keyProperty="id">
        INSERT INTO skill(name, level) VALUES (#{name}, #{level})
    insert>

    <update id="update" parameterType="Skill">
        UPDATE skill SET name = #{name}, level = #{level} WHERE id = #{id}
    update>

    <delete id="remove" parameterType="int">
        DELETE FROM skill WHERE id = #{id}
    delete>
mapper>

参考

小码哥-李明杰: Java从0到架构师③进阶互联网架构师.

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