SpringBoot+Mybatis 整合

前人总结的最佳实践案例可以帮助我们免去很多不必要的麻烦。要学会站在巨人人肩膀上看待问题；

项目环境：

• Intellij IDEA
• jdk: 1.8.0_171
• tomcat: 8.0.47
• maven: 3.5.2

插件：

• PageHelper 分页插件
• mybatis generator 自动生成代码插件

步骤：

1.创建一个springboot项目：

2.创建项目的文件结构以及 jdk的版本

3.选择项目所需要的依赖 

然后点击 Next ..最后 finish

4.看一下文件的结构：

5.编辑一下 pom.xml：

    4.0.0

    com.example
    springboot-mybatis-demo
    0.0.1-SNAPSHOT
    jar

    springboot-mybatis-demo
    Demo project for Spring Boot

    
        org.springframework.boot
        spring-boot-starter-parent
        2.0.4.RELEASE
         
    

    
        UTF-8
        UTF-8
        1.8
    

    
        
            org.springframework.boot
            spring-boot-starter-jdbc
        
        
            org.springframework.boot
            spring-boot-starter-thymeleaf
        
        
            org.springframework.boot
            spring-boot-starter-web
        
        
            org.mybatis.spring.boot
            mybatis-spring-boot-starter
            1.3.2
        

        
            mysql
            mysql-connector-java
            runtime
        
        
            org.springframework.boot
            spring-boot-starter-test
            test
        


        
        
            com.alibaba
            druid
            1.0.11
        
        
            com.fasterxml.jackson.core
            jackson-core
        
        
            com.fasterxml.jackson.core
            jackson-databind
        
        
            com.fasterxml.jackson.datatype
            jackson-datatype-joda
        
        
            com.fasterxml.jackson.module
            jackson-module-parameter-names
        
        
        
            com.github.pagehelper
            pagehelper-spring-boot-starter
            1.1.2
        
        
        
            com.alibaba
            druid-spring-boot-starter
            1.1.0
        

        

    

    
        
            
                org.springframework.boot
                spring-boot-maven-plugin
            
            
            
                org.mybatis.generator
                mybatis-generator-maven-plugin
                1.3.2
                
                    ${basedir}/src/main/resources/generator/generatorConfig.xml
                    true
                    true
                
            
        
    

6.创建数据库 

-- 第 1步创建数据库
CREATE DATABASE example_springboot;

-- 第 2步创建表
CREATE TABLE IF NOT EXISTS `tb_user`(
   `userId` INT UNSIGNED AUTO_INCREMENT,
   `userName` VARCHAR(100) NOT NULL,
   `password` VARCHAR(100) NOT NULL,
   `phone` VARCHAR(255) NOT NULL,
   `remark` VARCHAR(500),
   PRIMARY KEY ( `userid` )
)ENGINE=INNODB DEFAULT CHARSET=utf8;

7.项目不使用 application.properties文件 而使用更加简洁的 application.yml文件： 
将原有的 resource文件夹下的 application.properties文件删除，创建一个新的 application.yml配置文件， 

application.yml 文件的内容如下：

server:
  port: 8080

spring:
    datasource:
        name: test
        url: jdbc:mysql://127.0.0.1:3306/example_springboot
        username: root
        password: root
        # 使用druid数据源
        type: com.alibaba.druid.pool.DruidDataSource
        driver-class-name: com.mysql.jdbc.Driver
        filters: stat
        maxActive: 20
        initialSize: 1
        maxWait: 60000
        minIdle: 1
        timeBetweenEvictionRunsMillis: 60000
        minEvictableIdleTimeMillis: 300000
        validationQuery: select 'x'
        testWhileIdle: true
        testOnBorrow: false
        testOnReturn: false
        poolPreparedStatements: true
        maxOpenPreparedStatements: 20
mybatis:
  mapper-locations: classpath:mapping/*.xml
  type-aliases-package: com.example.springbootmybatisdemo.model

#pagehelper分页插件
pagehelper:
    helperDialect: mysql
    reasonable: true
    supportMethodsArguments: true
    params: count=countSql

8.使用mybatis generator 自动生成代码：

• mysql-connector-java-5.1.25-bin.jar
• 配置 pom.xml中 generator 插件所对应的配置文件 ${basedir}/src/main/resources/generator/generatorConfig.xml

9.点击 Run-Edit Configurations

10.编辑 Maven

• Command line:  mybatis-generator:generate -e
• 注意将 General 中 Maven信息修改为自己本地的

 

• 运行

 

• 最后生成的文件以及结构：

11.自动生成的文件

• User.java

package com.example.springbootmybatisdemo.model;

public class User {
    private Integer userId;

    private String userName;

    private String password;

    private String phone;

    private String remark;

    public Integer getUserId() {
        return userId;
    }

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

    public String getUserName() {
        return userName;
    }

    public void setUserName(String userName) {
        this.userName = userName == null ? null : userName.trim();
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password == null ? null : password.trim();
    }

    public String getPhone() {
        return phone;
    }

    public void setPhone(String phone) {
        this.phone = phone == null ? null : phone.trim();
    }

    public String getRemark() {
        return remark;
    }

    public void setRemark(String remark) {
        this.remark = remark == null ? null : remark.trim();
    }
}

• UserMapper.java

package com.example.springbootmybatisdemo.mapper;

import com.example.springbootmybatisdemo.model.User;

public interface UserMapper {
    int deleteByPrimaryKey(Integer userId);

    int insert(User record);

    int insertSelective(User record);

    User selectByPrimaryKey(Integer userId);

    int updateByPrimaryKeySelective(User record);

    int updateByPrimaryKey(User record);
}

• UserMapper.xml

  
    
    
    
    
    
  
  
    user_id, user_name, password, phone, remark
  
  
    select 
    
    from tb_user
    where user_id = #{userId,jdbcType=INTEGER}
  
  
    delete from tb_user
    where user_id = #{userId,jdbcType=INTEGER}
  
  
    insert into tb_user (user_id, user_name, password, 
      phone, remark)
    values (#{userId,jdbcType=INTEGER}, #{userName,jdbcType=VARCHAR}, #{password,jdbcType=VARCHAR}, 
      #{phone,jdbcType=VARCHAR}, #{remark,jdbcType=VARCHAR})
  
  
    insert into tb_user
    
      
        user_id,
      
      
        user_name,
      
      
        password,
      
      
        phone,
      
      
        remark,
      
    
    
      
        #{userId,jdbcType=INTEGER},
      
      
        #{userName,jdbcType=VARCHAR},
      
      
        #{password,jdbcType=VARCHAR},
      
      
        #{phone,jdbcType=VARCHAR},
      
      
        #{remark,jdbcType=VARCHAR},
      
    
  
  
    update tb_user
    
      
        user_name = #{userName,jdbcType=VARCHAR},
      
      
        password = #{password,jdbcType=VARCHAR},
      
      
        phone = #{phone,jdbcType=VARCHAR},
      
      
        remark = #{remark,jdbcType=VARCHAR},
      
    
    where user_id = #{userId,jdbcType=INTEGER}
  
  
    update tb_user
    set user_name = #{userName,jdbcType=VARCHAR},
      password = #{password,jdbcType=VARCHAR},
      phone = #{phone,jdbcType=VARCHAR},
      remark = #{remark,jdbcType=VARCHAR}
    where user_id = #{userId,jdbcType=INTEGER}
  

到这一步，就可以快速生成 bean与常用的 dao方法

12.打开类 SpringbootMybatisDemoApplication.java，这个是 springboot的启动类。我们需要添加点东西：

package com.example.springbootmybatisdemo;

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

@MapperScan("com.example.springbootmybatisdemo.mapper")//将项目中对应的 mapper类的路径加进来就可以了
@SpringBootApplication
public class SpringbootMybatisDemoApplication {

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

到这里所有的搭建工作都完成了,

接下来就可以写 Service 跟 Controller 了

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