Spring Boot使用mybatis连接mysql

     使用IDEA创建一个spring boot项目，项目名为springbootstudy，使用maven管理jar包。

1，修改pom.xml配置，配置如下：

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.jack</groupId>
    <artifactId>springbootstudy</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>springbootstudy</name>
    <description>Demo project for Spring Boot</description>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.5.4.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
    </properties>

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

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

       
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-eureka-server</artifactId>
            <version>1.3.1.RELEASE</version>
        </dependency>

        <!--feign方式远程调用需要的包-->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-feign</artifactId>
            <version>1.3.1.RELEASE</version>
        </dependency>

        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-ribbon</artifactId>
            <version>1.3.1.RELEASE</version>
        </dependency>

        <!-- 与数据库操作相关的依赖 -->
       <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jdbc</artifactId>
        </dependency>
        <!--mybatis与springboot整合包-->
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>1.3.0</version>
        </dependency>

        <!--mysql驱动-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>

        <!-- 使用druid数据源 -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.1.1</version>
        </dependency>

        <!-- mybatis包 -->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.4.4</version>
        </dependency>

        <dependency>
             <groupId>org.mybatis</groupId>
             <artifactId>mybatis-spring</artifactId>
             <version>1.3.1</version>
         </dependency>



    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>

    </build>


</project>

    需要听见mysql驱动包，mybatis包，mybatis和spring正和的包，采用阿里巴巴的数据druid做数据库连接池，mybatis与spring boot整合的包，spring boot的jdbc操作的包。

2，修改application.yml配置文件，代码如下：

server:
  port: 9092

spring:
  application:
    name: spring-cloud-consumer
  datasource:
    name: test
    url: jdbc:mysql://192.168.9.107:3306/jack?characterEncoding=utf8&useSSL=true
    username: root
    password: root
    #使用druid数据源
    type: com.alibaba.druid.pool.DruidDataSource
    driverClassName: 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:
  mapperLocations: classpath:mapper/*.xml  #指定*Mapper.xml的位置

#设置日志级别，打印mybatis的日志
logging:
  level:
    root: debug

   注意：需要开启mybatis操作的日志的话，需要修改loggin.level.root=debug，在resource目录下创建mapper目录，用于存放mybatis操作的sql文件。

3，创建mybatis的配置类，代码如下：

package com.jack.config;


import com.alibaba.druid.pool.DruidDataSource;
import org.apache.ibatis.logging.LogFactory;
import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionFactoryBean;
import org.mybatis.spring.SqlSessionTemplate;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.env.Environment;
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
import org.springframework.core.io.support.ResourcePatternResolver;
import org.springframework.jdbc.datasource.DataSourceTransactionManager;

import javax.sql.DataSource;

/**
 * Created by jackc on 2017/7/20.
 */
@Configuration
public class MybatisConfig {
    /**
     * 注入环境变量的值
     */
    @Autowired
    private Environment environment;

    /**
     * 获取数据源DataSource
     * @return
     */
    @Bean
    public DataSource druidDataSource() {
        DruidDataSource druidDataSource = new DruidDataSource();
        druidDataSource.setUrl(environment.getProperty("spring.datasource.url"));
        druidDataSource.setUsername(environment.getProperty("spring.datasource.username"));
        druidDataSource.setPassword(environment.getProperty("spring.datasource.password"));
        druidDataSource.setDriverClassName(environment.getProperty("spring.datasource.driverClassName"));
        druidDataSource.setMaxActive(Integer.parseInt(environment.getProperty("spring.datasource.maxActive")));
        druidDataSource.setInitialSize(Integer.parseInt(environment.getProperty("spring.datasource.initialSize")));
        druidDataSource.setMaxWait(Long.parseLong(environment.getProperty("spring.datasource.maxWait")));
        druidDataSource.setMinIdle(Integer.parseInt(environment.getProperty("spring.datasource.minIdle")));
        druidDataSource.setTimeBetweenEvictionRunsMillis(Long.parseLong(environment.getProperty("spring.datasource.timeBetweenEvictionRunsMillis")));
        druidDataSource.setMinEvictableIdleTimeMillis(Long.parseLong(environment.getProperty("spring.datasource.minEvictableIdleTimeMillis")));
        druidDataSource.setValidationQuery(environment.getProperty("spring.datasource.validationQuery"));
        druidDataSource.setTestWhileIdle(Boolean.parseBoolean(environment.getProperty("spring.datasource.testWhileIdle")));
        druidDataSource.setTestOnBorrow(Boolean.parseBoolean(environment.getProperty("spring.datasource.testOnBorrow")));
        druidDataSource.setTestOnReturn(Boolean.parseBoolean(environment.getProperty("spring.datasource.testOnReturn")));
        druidDataSource.setPoolPreparedStatements(Boolean.parseBoolean(environment.getProperty("spring.datasource.poolPreparedStatements")));
        druidDataSource.setMaxOpenPreparedStatements(Integer.parseInt(environment.getProperty("spring.datasource.maxOpenPreparedStatements")));
        return druidDataSource;
    }

    /**
     * 获取SqlSessionFactory
     * @param druidDataSource
     * @return
     */
    @Bean(name = "sqlSessionFactory")
    public SqlSessionFactory sqlSessionFactoryBean(DataSource druidDataSource) {
        SqlSessionFactoryBean bean = new SqlSessionFactoryBean();
        bean.setDataSource(druidDataSource);
        LogFactory.useLog4JLogging();
        //添加XML目录
        ResourcePatternResolver resolver = new PathMatchingResourcePatternResolver();
        String xmlPath = environment.getProperty("mybatis.mapperLocations");
        try {
            bean.setMapperLocations(resolver.getResources(xmlPath));
            return bean.getObject();
        } catch (Exception e) {
            e.printStackTrace();
            throw new RuntimeException(e);
        }
    }

    /**
     *
     * @param sqlSessionFactory
     * @return
     */
    @Bean
    public SqlSessionTemplate sqlSessionTemplate(SqlSessionFactory sqlSessionFactory) {
        return new SqlSessionTemplate(sqlSessionFactory);
    }

    /**
     * 增加事务
     * @param druidDataSource
     * @return
     */
    @Bean
    public DataSourceTransactionManager transactionManager(DataSource druidDataSource) {
        return new DataSourceTransactionManager(druidDataSource);
    }
}

4，创建一个配置类，进行mapper接口的扫描，通过调用这些接口，进而调用配置的sql操作数据库。

package com.jack.config;

import org.mybatis.spring.mapper.MapperScannerConfigurer;
import org.springframework.boot.autoconfigure.AutoConfigureAfter;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

/**
 * Created by jack on 2017/7/20.
 */
@Configuration
//注意，由于MabatisMapperScanConfig执行的比较早，所以必须有下面的注解
@AutoConfigureAfter(MybatisConfig.class)
public class MabatisMapperScanConfig {
    @Bean
    public MapperScannerConfigurer mapperScannerConfigurer() {
        MapperScannerConfigurer mapperScannerConfigurer = new MapperScannerConfigurer();
        //注意这里的sqlSessionFactory就是MybatisConfig里面的sqlSessionFactoryBean方法，注解bean的名字
        mapperScannerConfigurer.setSqlSessionFactoryBeanName("sqlSessionFactory");
        //接口路径，通过这些接口调用sql的配置，操作数据库
        mapperScannerConfigurer.setBasePackage("com.jack.mapper");
        return mapperScannerConfigurer;
    }
}

5，创建一个一个com.jack.mapper包，里面存放数据库操作的接口文件，下面创建一个测试的接口，代码如下：

package com.jack.mapper;

import com.google.common.annotations.VisibleForTesting;
import com.jack.entity.Test;

import java.util.List;

/**
 * Created by jack on 2017/7/20.
 * 接口，对Test表进行操作
 */
public interface TestMapper {
    Test findTestById(int id);

    int add(Test test);

    int deleteById(int id);

    int updateByID(Test test);

    List<Test> findByName(String name);
}

6，创建一个com.jack.entity包里面存放对应的数据库表的类，测试类代码如下：

package com.jack.entity;

/**
 * Created by jack on 2017/7/20.
 */
public class Test {
    private int id;
    private String name;
    private String note;

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getNote() {
        return note;
    }

    public void setNote(String note) {
        this.note = note;
    }

    @Override
    public String toString() {
        return "Test{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", note='" + note + '\'' +
                '}';
    }
}

7，在resource/mapper目录下创建一个TestMapper.xml文件，代码如下：

<?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.jack.mapper.TestMapper" >

    <!--通过id查找-->
    <select id="findTestById" parameterType="int" resultType="com.jack.entity.Test">
        SELECT * from test where id = #{id}
    </select>
    <!--增加-->
    <insert id="add" parameterType="com.jack.entity.Test">
        INSERT INTO test(name,note) VALUES (#{name},#{note})
    </insert>
    <!--删除-->
    <delete id="deleteById" parameterType="int">
        DELETE FROM test where id = #{id}
    </delete>
    <!--更新-->
    <update id="updateByID" parameterType="com.jack.entity.Test">
        UPDATE test SET NAME =#{name},note =#{note} where id = #{id}
    </update>
    <!--模糊查询-->
    <select id="findByName" parameterType="string" resultType="com.jack.entity.Test">
        SELECT id,name,note from test where name like concat('%',#{name},'%')
    </select>
</mapper>

8，创建一个测试的controller，代码如下：

package com.jack.controller;

import com.jack.entity.Test;
import com.jack.mapper.TestMapper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.List;

/**
 * Created by jack on 2017/7/20.
 */
@RestController
public class TestController {
    @Autowired
    TestMapper testMapper;

    /**
     * 通过id进行查询
     * @return
     */
    @RequestMapping(value = "/find/id")
    public String fingTestById(){
        return testMapper.findTestById(1).toString();
    }

    /**
     * 添加
     * @return
     */
    @RequestMapping(value = "/add")
    public String  addTest(){
        Test test = new Test();
        test.setName("jack add");
        test.setNote("this is add element to test table");
        int result= testMapper.add(test);
        System.out.println("add result ="+result);
        if (result >0) {
            return "添加成功";
        }else {
            return "添加失败";
        }

    }

    /**
     * 通过id删除
     * @return
     */
    @RequestMapping(value = "/delete")
    public String  deleteTestById(){

        int result= testMapper.deleteById(5);
        System.out.println("deleteTestById result ="+result);
        if (result > 0) {
            return "删除成功";
        } else {
            return "删除失败";
        }
    }

    /**
     * 通过id更新
     * @return
     */
    @RequestMapping(value = "/update")
    public String  updateTestById(){
        Test test = new Test();
        test.setId(6);
        test.setName("this is updete name ");
        test.setNote("this is update note");
        int result= testMapper.updateByID(test);
        System.out.println("updateTestById result ="+result);
        if (result > 0) {
            return "更新成功";
        } else {
            return "更新失败";
        }
    }

    /**
     * 通过名字进行模糊查询
     * @return
     */
    @RequestMapping(value = "/findname")
    public String  findByName(){
        List<Test> result= testMapper.findByName("jack");
        System.out.println("updateTestById result ="+result.toString());
        if (result != null) {
            return "更新成功";
        } else {
            return "更新失败";
        }
    }
}

9，测试数据库的设计

     1，创建一个名为jack的数据库

     2，创建一个test表，sql语句如下：

/*
Navicat MySQL Data Transfer

Source Server         : MyLocalMySQL192.168.9.107
Source Server Version : 50718
Source Host           : 192.168.9.107:3306
Source Database       : jack

Target Server Type    : MYSQL
Target Server Version : 50718
File Encoding         : 65001

Date: 2017-07-21 14:24:34
*/

SET FOREIGN_KEY_CHECKS=0;

-- ----------------------------
-- Table structure for test
-- ----------------------------
DROP TABLE IF EXISTS `test`;
CREATE TABLE `test` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `name` varchar(20) DEFAULT NULL,
  `note` varchar(100) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=9 DEFAULT CHARSET=utf8;

10，启动这个项目，通过浏览器，输入相应的路径进行测试，通过controller调用接口，进而调用sql操作数据库，看日志，有mybatis调用的日志输出，查看数据库，看对数据库表的操作后有什么变化。