SpringBoot Mybatis连接MySQL数据库

SpringBoot整合Mybatis还是比较简单的，本篇文章讲解使用Mapper.xml来写SQL。

（1）build.gradle文件添加依赖

    // https://mvnrepository.com/artifact/com.github.pagehelper/pagehelper
    compile group: 'com.github.pagehelper', name: 'pagehelper', version: '5.1.2'


    // https://mvnrepository.com/artifact/mysql/mysql-connector-java
    compile group: 'mysql', name: 'mysql-connector-java', version: '6.0.6'

    // https://mvnrepository.com/artifact/org.mybatis.spring.boot/mybatis-spring-boot-starter
    compile group: 'org.mybatis.spring.boot', name: 'mybatis-spring-boot-starter', version: '1.3.2'

（2）数据库表结构

数据库为wzj，数据库表为teacher，创建表语句如下：

create table teacher(
 tec_id varchar(16) not null primary key,
 tec_name varchar(16) not null,
 tec_age tinyint unsigned,
 tec_desc varchar(128)
);

数据库有一条数据

（3）工程结构

controller--控制器包

entity--实体类，和数据库表结构映射

mybatis--mybatis配置

resources/mapper-- sql语句

（4）添加@MapperScan注解

在SpringBoot启动类上添加@MapperScan("com.wzj.demo.mapper")，com.wzj.demo.mapper为mapper接口的包

package com.wzj.demo;

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.builder.SpringApplicationBuilder;
import org.springframework.boot.web.support.SpringBootServletInitializer;

@SpringBootApplication
@MapperScan("com.wzj.demo.mapper")
public class SpringBootWebSocketApplication  extends SpringBootServletInitializer{

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

	/**
	 * Configure the application. Normally all you would need to do it add sources (e.g.
	 * config classes) because other settings have sensible defaults. You might choose
	 * (for instance) to add default command line arguments, or set an active Spring
	 * profile.
	 *
	 * @param builder a builder for the application context
	 * @return the application builder
	 * @see SpringApplicationBuilder
	 */
	@Override
	protected SpringApplicationBuilder configure(SpringApplicationBuilder builder)
	{
		return super.configure(builder);
	}
}

（5）添加MySQL数据库连接配置到application.properties

下面是我的数据库连接参数，将下面几行，添加到application.properties中

spring.datasource.url = jdbc:mysql://192.168.3.45:3306/wzj
spring.datasource.username=root
spring.datasource.password=12345
spring.datasource.driverClassName=com.mysql.jdbc.Driver

（6）新建MyBatisConfiguration.java文件

package com.wzj.demo.mybaties;

import com.github.pagehelper.PageHelper;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import java.util.Properties;

/**
 * Created by wzj on 2018/3/17.
 */
@Configuration
@ConfigurationProperties(prefix = "spring.datasource")
public class MyBatisConfiguration
{
    /**
     * url
     */
    private String url;

    /**
     * 驱动名称
     */
    private String driverClassName;

    /**
     * 数据库名
     */
    private String username;

    /**
     * 数据库密码
     */
    private String password;

    public String getUrl()
    {
        return url;
    }

    public void setUrl(String url)
    {
        this.url = url;
    }

    public String getDriverClassName()
    {
        return driverClassName;
    }

    public void setDriverClassName(String driverClassName)
    {
        this.driverClassName = driverClassName;
    }

    public String getUsername()
    {
        return username;
    }

    public void setUsername(String username)
    {
        this.username = username;
    }

    public String getPassword()
    {
        return password;
    }

    public void setPassword(String password)
    {
        this.password = password;
    }

    @Bean
    public PageHelper pageHelper() {
        System.out.println("MyBatisConfiguration.pageHelper()");
        PageHelper pageHelper = new PageHelper();
        Properties p = new Properties();
        p.setProperty("offsetAsPageNum", "true");
        p.setProperty("rowBoundsWithCount", "true");
        p.setProperty("reasonable", "true");
        pageHelper.setProperties(p);
        return pageHelper;
    }

//    @Bean(name = "dataSource")
//    public DriverManagerDataSource dataSource(){
//        DriverManagerDataSource driverManagerDataSource = new DriverManagerDataSource();
//        driverManagerDataSource.setDriverClassName(driverClassName);
//        driverManagerDataSource.setUrl(url);
//        driverManagerDataSource.setUsername(username);
//        driverManagerDataSource.setPassword(password);
//        return driverManagerDataSource;
//    }


}

（7）新建TeacherBean.java实体类,和数据库表结构映射

package com.wzj.demo.entity;

/**
 * Created by wzj on 2018/3/17.
 */
public class TeacherBean
{
    private String tecId;

    private String tecName;

    private int tecAge;

    private String tecDesc;


    public String getTecId()
    {
        return tecId;
    }

    public void setTecId(String tecId)
    {
        this.tecId = tecId;
    }

    public String getTecName()
    {
        return tecName;
    }

    public void setTecName(String tecName)
    {
        this.tecName = tecName;
    }

    public int getTecAge()
    {
        return tecAge;
    }

    public void setTecAge(int tecAge)
    {
        this.tecAge = tecAge;
    }

    public String getTecDesc()
    {
        return tecDesc;
    }

    public void setTecDesc(String tecDesc)
    {
        this.tecDesc = tecDesc;
    }

    @Override
    public String toString()
    {
        return "TeacherBean{" + "tecId='" + tecId + '\'' + ", tecName='" + tecName + '\'' + ", tecAge=" + tecAge + ", tecDesc='" + tecDesc + '\'' + '}';
    }
}

（8）新建TeacherMapper.java文件

该文件定义数据库查询接口

package com.wzj.demo.mapper;

import com.wzj.demo.entity.TeacherBean;
import org.apache.ibatis.annotations.Param;

/**
 * Created by wzj on 2018/3/18.
 */
public interface TeacherMapper
{
    /**
     * 通过id查询老师信息
     * @param id id
     * @return teacher信息
     */
    TeacherBean getTeacherById(@Param("id") String id);
}

（9）在/resources/mapper/目录新建TeacherMapper.xml文件

该文件实现上一步中定义的数据库接口

    
        
        
        
    

    
        tec_id, tec_name, tec_age
    

    
        select
        
        from teacher
        where tec_id = #{id}
    

（10）新建控制器TeacherController.java和服务TeacherService.java

package com.wzj.demo.controller;

import com.wzj.demo.service.TeacherService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

/**
 * Created by wzj on 2018/3/18.
 */
@RestController
public class TeacherController
{
    /**
     * 注入服务
     */
    @Autowired
    private TeacherService teacherService;

    /**
     * 查询老师信息
     * @param id id
     * @return 信息
     */
    @RequestMapping(value = "/teacher")
    public String getTeacherMessage(String id)
    {
        return teacherService.queryTeacher(id).toString();
    }
}

package com.wzj.demo.service;

import com.wzj.demo.entity.TeacherBean;
import com.wzj.demo.mapper.TeacherMapper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

/**
 * Created by wzj on 2018/3/18.
 */
@Service
public class TeacherService
{
    /**
     * 注入服务
     */
    @Autowired
    private TeacherMapper teacherMapper;

    public TeacherBean queryTeacher(String id)
    {
        return teacherMapper.getTeacherById(id);
    }
}

（11）测试

启动SpringBoot，浏览器输入http://127.0.0.1:8080/teacher?id=1001

Demo Github地址： https://github.com/HelloKittyNII/SpringBoot/tree/master/SpringBootDemo