使用MyBatis的准备工作

一、使用软件（IDEA）
二、在pom.xml注入依赖(为了方便直接导入SSM依赖)

<dependency>
    <groupId>org.springframeworkgroupId>
    <artifactId>spring-webmvcartifactId>
    <version>5.2.2.RELEASEversion>
dependency>

<dependency>
    <groupId>org.springframeworkgroupId>
    <artifactId>spring-jdbcartifactId>
    <version>5.2.2.RELEASEversion>
dependency>

<dependency>
    <groupId>org.mybatisgroupId>
    <artifactId>mybatisartifactId>
    <version>3.5.0version>
dependency>

<dependency>
    <groupId>org.mybatisgroupId>
    <artifactId>mybatis-springartifactId>
    <version>2.0.1version>
dependency>

<dependency>
    <groupId>org.thymeleafgroupId>
    <artifactId>thymeleafartifactId>
    <version>3.0.11.RELEASEversion>
dependency>

<dependency>
    <groupId>org.thymeleafgroupId>
    <artifactId>thymeleaf-spring5artifactId>
    <version>3.0.11.RELEASEversion>
dependency>

<dependency>
    <groupId>mysqlgroupId>
    <artifactId>mysql-connector-javaartifactId>
    <version>8.0.15version>
dependency>

<dependency>
    <groupId>com.alibabagroupId>
    <artifactId>druidartifactId>
    <version>1.1.21version>
dependency>

<dependency>
    <groupId>junitgroupId>
    <artifactId>junitartifactId>
    <version>4.13version>
    <scope>testscope>
dependency>
<dependency>
    <groupId>javax.servletgroupId>
    <artifactId>javax.servlet-apiartifactId>
    <version>3.1.0version>
    <scope>providedscope>
dependency>
<dependency>
    <groupId>org.slf4jgroupId>
    <artifactId>slf4j-log4j12artifactId>
    <version>1.7.25version>
dependency>

三、在resources文件夹下配置jdbc.properties文件

db.driver=com.mysql.cj.jdbc.Driver
db.url=jdbc:mysql://localhost:3306/mysql?characterEncoding=utf8&useSSL=false&serverTimezone=Asia/Shanghai&rewriteBatchedStatements=true
db.username=root
db.password=root
db.maxActive=10
db.initialSize=2

四、编写Mybatis配置类（一般放在专门放配置文件的文件夹下,这里是config）

@PropertySource("classpath:jdbc.properties")
public class MyBatisConfig {
    @Bean
    public DataSource dataSource(
            @Value("${db.driver}") String driver,
            @Value("${db.url}") String url,
            @Value("${db.username}") String username,
            @Value("${db.password}") String password,
            @Value("${db.maxActive}") int maxActive,
            @Value("${db.initialSize}") int initialSize) {
        DruidDataSource ds = new DruidDataSource();
        ds.setDriverClassName(driver);
        ds.setUrl(url);
        ds.setUsername(username);
        ds.setPassword(password);
        ds.setMaxActive(maxActive);
        ds.setInitialSize(initialSize);
        return ds;
    }
}

五、测试（使用Java单元测试Junit）

 @Test
    public void testDataSource() throws SQLException {
        DataSource ds=ctx.getBean(
                "dataSource",DataSource.class);
        String sql="select username from vrduser where id=1";
        try (Connection conn=ds.getConnection()){
            Statement st=conn.createStatement();
            ResultSet rs=st.executeQuery(sql);
            while(rs.next()){
                System.out.println(rs.getString(1));
            }
        }catch (Exception e){
            e.printStackTrace();
        }
    }