Springboot：整合Mybatis

1、導入依賴

mybatis依賴：

<dependency>
    <groupId>org.mybatis.spring.boot</groupId>
    <artifactId>mybatis-spring-boot-starter</artifactId>
    <version>2.1.1</version>
</dependency>      

其它依賴：

<dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.1.21</version>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.8</version>
            <scope>runtime</scope>
        </dependency>      

2、配置資料庫連接配接

spring:
  datasource:
    username: root
    password: root
    driver-class-name: com.mysql.jdbc.Driver
    url: jdbc:mysql://localhost:3306/stu_mangement?serverTimezone=UTC&useUnicode=true&characterEncoding=utf-8
    type: com.alibaba.druid.pool.DruidDataSource

    #Spring Boot 預設是不注入這些屬性值的，需要自己綁定
    #druid 資料源專有配置
    initialSize: 5
    minIdle: 5
    maxActive: 20
    maxWait: 60000
    timeBetweenEvictionRunsMillis: 60000
    minEvictableIdleTimeMillis: 300000
    validationQuery: SELECT 1 FROM DUAL
    testWhileIdle: true
    testOnBorrow: false
    testOnReturn: false
    poolPreparedStatements: true

    #配置監控統計攔截的filters，stat:監控統計、log4j：日志記錄、wall：防禦sql注入
    #如果允許時報錯  java.lang.ClassNotFoundException: org.apache.log4j.Priority
    #則導入 log4j 依賴即可，Maven 位址：https://mvnrepository.com/artifact/log4j/log4j
    filters: stat,wall,log4j
    maxPoolPreparedStatementPerConnectionSize: 20
    useGlobalDataSourceStat: true
    connectionProperties: druid.stat.mergeSql=true;druid.stat.slowSqlMillis=500      

3、建立一個實體類Student，使用了lombok需要導入相應的依賴

@Data
public class Student {
    public Integer studentno;
    public String birthday;
    public String classno;
    public String phone;
    public String sex;
    public String sname;
    public Float point;
}      

4、dao層

（1）建立dao層的接口

@Component
public interface StudentDao {
    List<Student> getStudents();
}      

（2）在resources目錄下建立配置檔案

<?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.zhb.dao.StudentDao">
    <select id="getStudents" resultType="com.zhb.pojo.Student">
       select * from student;
    </select>
</mapper>      

（3）注意

為了保證編譯後的接口和配置檔案在同一個目錄下，書寫接口與配置的時候需要注意目錄的建立方式：

 編譯結果：

5、測試

書寫controller嘗試擷取資料：

@Controller
public class JDBCController {
    @Autowired
    StudentDao studentDao;
    @RequestMapping("/query")
    public String queryAll() {
        System.out.println(studentDao.getStudents());
        return "query";
    }
}      

測試結果：成功擷取到資料