简介

SpringBoot整合MyBatis，我这里使用的是SpringBoot1.4.7。

知识点：

• 1.SpringBoot集成MyBatis
• 2.PageHelper分页插件使用
• 3.MyBatis代码自动生成器集成
• 4.通过自定义转换器formatter日期对象

SpringBoot集成MyBatis

• 1.通过maven方式引入依赖jar

<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.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-lang3</artifactId>
            <version>3.4</version>
        </dependency>


        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-core</artifactId>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.datatype</groupId>
            <artifactId>jackson-datatype-joda</artifactId>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.module</groupId>
            <artifactId>jackson-module-parameter-names</artifactId>
        </dependency>
        <!-- 分页插件 -->
        <dependency>
            <groupId>com.github.pagehelper</groupId>
            <artifactId>pagehelper</artifactId>
            <version>5.1.3</version>
        </dependency>
        <!-- alibaba的druid数据库连接池 -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid-spring-boot-starter</artifactId>
            <version>1.1.0</version>
        </dependency>

maven依赖成功加载完后，在工程java源码目录中创建：
config、controller、dao、model、service包以及在资源目录中创建mapper目录。

mybatisdir.jpg

至于项目包名可自行而定。

• 2.创建配置@Configuration

在config包中分别创建：
DataSourceConfig.java ---数据源配置
DruidDBConfig.java ---数据库连接池DruidDB配置
PageHelperConfig.java ---分页插件配置

DataSourceConfig.java:

import com.github.pagehelper.PageInterceptor;
import org.apache.ibatis.plugin.Interceptor;
import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionFactoryBean;
import org.mybatis.spring.annotation.MapperScan;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
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.transaction.annotation.EnableTransactionManagement;

import javax.sql.DataSource;


@Configuration
@MapperScan("com.yu.scloud.baseframe.frame.dao")
@EnableTransactionManagement
public class DataSourceConfig {


    private static Logger logger = LoggerFactory.getLogger(DataSourceConfig.class);

    @Autowired
    private Environment env;

    @Autowired
    private PageInterceptor pageInterceptor;

    @Bean
    public SqlSessionFactory sqlSessionFactory(DataSource dataSource) throws Exception {
        SqlSessionFactoryBean fb = new SqlSessionFactoryBean();
        fb.setDataSource(dataSource);
        //该配置非常的重要，如果不将PageInterceptor设置到SqlSessionFactoryBean中，导致分页失效
        fb.setPlugins(new Interceptor[]{pageInterceptor});
        fb.setTypeAliasesPackage(env.getProperty("mybatis.type-aliases-package"));
        fb.setMapperLocations(new PathMatchingResourcePatternResolver().getResources(env.getProperty("mybatis.mapper-locations")));
        return fb.getObject();
    }
}

DruidDBConfig.java :

import com.alibaba.druid.pool.DruidDataSource;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Primary;

import javax.sql.DataSource;
import java.sql.SQLException;


@Configuration
public class DruidDBConfig {
    private Logger logger = LoggerFactory.getLogger(DruidDBConfig.class);

    @Value("${spring.datasource.url}")
    private String dbUrl;

    @Value("${spring.datasource.username}")
    private String username;

    @Value("${spring.datasource.password}")
    private String password;

    @Value("${spring.datasource.driver-class-name}")
    private String driverClassName;

    @Value("${spring.datasource.initialSize}")
    private int initialSize;

    @Value("${spring.datasource.minIdle}")
    private int minIdle;

    @Value("${spring.datasource.maxActive}")
    private int maxActive;

    @Value("${spring.datasource.maxWait}")
    private int maxWait;

    @Value("${spring.datasource.timeBetweenEvictionRunsMillis}")
    private int timeBetweenEvictionRunsMillis;

    @Value("${spring.datasource.minEvictableIdleTimeMillis}")
    private int minEvictableIdleTimeMillis;

    @Value("${spring.datasource.validationQuery}")
    private String validationQuery;

    @Value("${spring.datasource.testWhileIdle}")
    private boolean testWhileIdle;

    @Value("${spring.datasource.testOnBorrow}")
    private boolean testOnBorrow;

    @Value("${spring.datasource.testOnReturn}")
    private boolean testOnReturn;

    @Value("${spring.datasource.poolPreparedStatements}")
    private boolean poolPreparedStatements;

    @Value("${spring.datasource.maxPoolPreparedStatementPerConnectionSize}")
    private int maxPoolPreparedStatementPerConnectionSize;

    @Value("${spring.datasource.filters}")
    private String filters;

    @Value("{spring.datasource.connectionProperties}")
    private String connectionProperties;

    @Bean     //声明其为Bean实例
    @Primary  //在同样的DataSource中，首先使用被标注的DataSource
    public DataSource dataSource(){
        DruidDataSource datasource = new DruidDataSource();

        datasource.setUrl(this.dbUrl);
        datasource.setUsername(username);
        datasource.setPassword(password);
        datasource.setDriverClassName(driverClassName);

        //configuration
        datasource.setInitialSize(initialSize);
        datasource.setMinIdle(minIdle);
        datasource.setMaxActive(maxActive);
        datasource.setMaxWait(maxWait);
        datasource.setTimeBetweenEvictionRunsMillis(timeBetweenEvictionRunsMillis);
        datasource.setMinEvictableIdleTimeMillis(minEvictableIdleTimeMillis);
        datasource.setValidationQuery(validationQuery);
        datasource.setTestWhileIdle(testWhileIdle);
        datasource.setTestOnBorrow(testOnBorrow);
        datasource.setTestOnReturn(testOnReturn);
        datasource.setPoolPreparedStatements(poolPreparedStatements);
        datasource.setMaxPoolPreparedStatementPerConnectionSize(maxPoolPreparedStatementPerConnectionSize);
        try {
            datasource.setFilters(filters);
        } catch (SQLException e) {
            logger.error("druid configuration initialization filter", e);
        }
        datasource.setConnectionProperties(connectionProperties);

        return datasource;
    }
}

PageHelperConfig.java:

import com.github.pagehelper.PageInterceptor;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import java.util.Properties;

/**
 * 分页插件的配置
 */
@Configuration
public class PageHelperConfig {


    @Value("${pagehelper.helperDialect}")
    private String helperDialect;


    @Bean
    public PageInterceptor pageInterceptor(){
        PageInterceptor pageInterceptor = new PageInterceptor();
        Properties properties = new Properties();
        properties.setProperty("helperDialect", helperDialect);
        pageInterceptor.setProperties(properties);
        return pageInterceptor;
    }
}

细心的朋友会发现以上三个配置类中都引用了properties中相关配置参数。
项目中的 application.properties 文件内容如下：

####单点式配置######
server.context-path=/bf
server.port=8002
####数据库相关####
spring.datasource.name=babystore
spring.datasource.url=jdbc:mysql://127.0.0.1:3306/apptest?useSSL=false&useUnicode=true&characterEncoding=UTF-8&allowMultiQueries=true
spring.datasource.username=root
spring.datasource.password=yu123456
#使用druid数据源
spring.datasource.type=com.alibaba.druid.pool.DruidDataSource
spring.datasource.driver-class-name=com.mysql.jdbc.Driver
#配置DruidDBConfig连接池
spring.datasource.filters=stat
spring.datasource.maxActive=20
spring.datasource.initialSize=1
spring.datasource.maxWait=60000
spring.datasource.minIdle=1
spring.datasource.timeBetweenEvictionRunsMillis=60000
spring.datasource.minEvictableIdleTimeMillis=300000
spring.datasource.validationQuery=select 'x'
spring.datasource.testWhileIdle=true
spring.datasource.testOnBorrow=false
spring.datasource.testOnReturn=false
spring.datasource.poolPreparedStatements=true
spring.datasource.maxPoolPreparedStatementPerConnectionSize=20
spring.datasource.maxOpenPreparedStatements=20
#mybatic
mybatis.mapper-locations=classpath:mapper/*.xml
mybatis.type-aliases-package=com.yu.scloud.baseframe.frame.model
mapper.mappers=com.yu.scloud.baseframe.frame.dao
mapper.not-empty=false
mapper.identity=MYSQL

#pagehelper
pagehelper.helperDialect=mysql

• 3.创建数据库表
  
  image.png

我们在一个叫做 “apptest” 的数据库中创建一个简单的user表结构。

• 4.创建Entity、dao、以及mapper映射xml文件

在 *.model/ 包中创建实体类 User.java

public class User {
    int id;
    String email;
    String password;
    String phone;
    String uid;
    String username;

    //......setter/getter方法省略显示
}

在 *.dao/ 包中创建UserDao.java接口

import com.yu.scloud.baseframe.frame.model.User;

import java.util.List;

public interface UserDao {

    int insert(User record);

    List<User> selectUsers();
}

在resources/mapper包中创建 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.yu.scloud.baseframe.frame.dao.UserDao" >
    <sql id="BASE_TABLE">
        user
    </sql>

    <sql id="BASE_COLUMN">
        id,email,password,phone,uid,username
    </sql>

    <insert id="insert" parameterType="com.yu.scloud.baseframe.frame.model.User">
        INSERT INTO
        <include refid="BASE_TABLE"/>
        <trim prefix="(" suffix=")" suffixOverrides=",">
            username,password,
            <if test="phone != null">
                phone,
            </if>
            <if test="email != null">
                email,
            </if>
            <if test="uid != null">
                uid,
            </if>
        </trim>
        <trim prefix="VALUES(" suffix=")" suffixOverrides=",">
            #{username, jdbcType=VARCHAR},#{password, jdbcType=VARCHAR},
            <if test="phone != null">
                #{phone, jdbcType=VARCHAR},
            </if>
            <if test="email != null">
                #{email,jdbcType=VARCHAR},
            </if>
            <if test="uid != null">
                #{uid,jdbcType=VARCHAR},
            </if>
        </trim>
    </insert>

    <select id="selectUsers" resultType="com.yu.scloud.baseframe.frame.model.User">
        SELECT
        <include refid="BASE_COLUMN"/>
        FROM
        <include refid="BASE_TABLE"/>
    </select>


</mapper>

• 5.创建Service和Controller使用MyBatis

创建UserService.java接口以及实现类 UserServiceImpl.java
创建MyBatisTestController.java类

UserService.java接口:

import com.yu.scloud.baseframe.frame.model.User;

import java.util.List;

public interface UserService {

    int addUser(User user);

    List<User> findAllUser(int pageNum, int pageSize);


}

UserServiceImpl.java：

import com.github.pagehelper.PageHelper;
import com.yu.scloud.baseframe.frame.dao.UserDao;
import com.yu.scloud.baseframe.frame.model.User;
import com.yu.scloud.baseframe.frame.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;

@Service(value = "userService")
public class UserServiceImpl implements UserService {

    @Autowired
    private UserDao userDao;//这里会报错，但是并不会影响

    @Override
    public int addUser(User user) {

        return userDao.insert(user);
    }

    /*
     * 这个方法中用到了我们开头配置依赖的分页插件pagehelper
     * 很简单，只需要在service层传入参数，然后将参数传递给一个插件的一个静态方法即可；
     * pageNum 开始页数
     * pageSize 每页显示的数据条数
     * */
    @Override
    public List<User> findAllUser(int pageNum, int pageSize) {
        //将参数传给这个方法就可以实现物理分页了，非常简单。
        PageHelper.startPage(pageNum, pageSize);
        return userDao.selectUsers();
    }
}

MyBatisTestController.java:

import com.github.pagehelper.PageHelper;
import com.yu.scloud.baseframe.frame.model.User;
import com.yu.scloud.baseframe.frame.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;

@RestController
@RequestMapping(value = "/user")
public class MyBatisTestController {


    @Autowired
    private UserService userService;

    @ResponseBody
    @PostMapping("/add")
    public int addUser(User user){
        return userService.addUser(user);
    }

    @ResponseBody
    @GetMapping("/all")
    public Object findAllUser(
            @RequestParam(name = "pageNum", required = false, defaultValue = "1")
                    int pageNum,
            @RequestParam(name = "pageSize", required = false, defaultValue = "10")
                    int pageSize){
        //开始分页
        PageHelper.startPage(pageNum,pageSize);
        return userService.findAllUser(pageNum,pageSize);
    }

  

}

ok!至此，SpringBoot集成Mybatis以及使用PageHelper分页插件的例子完成，赶快访问一下controller试一下吧，成功的话会通过mybatis插入数据库user数据也可以获取数据库数据。

这篇文章稍微有点长，不易阅读，下面两个知识点放到另一篇文章中讲解吧。
3.MyBatis代码自动生成器集成
4.通过自定义转换器formatter日期对象

参考 https://blog.csdn.net/Winter_chen001/article/details/80010967
代码自动生成器 https://www.cnblogs.com/hongdada/p/7583625.html