从零搭建springboot服务02-内嵌持久层框架Mybatis

愿历尽千帆，归来仍是少年

内嵌持久层框架Mybatis

1.所需依赖

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

        <!--mybatis  -->
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>${mybatis.version}</version>
        </dependency>

        <!--阿里数据库连接池 -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid-spring-boot-starter</artifactId>
            <version>${druid.version}</version>
        </dependency>

        <!-- 加入log4j2的日志框架 -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-log4j2</artifactId>
        </dependency>

2.配置application.yml文件

## 环境配置
server:
  # 服务器HTTP端口，默认端口:9999
  port: 9999
  servlet:
    # 项目访问路径
    context-path: /
  tomcat:
    # tomcat URI编码
    uri-encoding: UTF-8
    # tomcat最大线程数，默认为200
    max-threads: 800
    # tomcat启动初始化的线程数，默认25
    min-spare-threads: 25

## 数据库配置
spring:
  datasource:
    # 数据库连接池类型
    type: com.alibaba.druid.pool.DruidDataSource
    # mysql驱动 com.mysql.jdbc.Driver 是 mysql-connector-java 5中的， com.mysql.cj.jdbc.Driver 是 mysql-connector-java 6中的
    driver-class-name: com.mysql.cj.jdbc.Driver
    druid:
      url:xxx
      username: xxx
      password: xxx

mybatis:
  # 指定mapper.xml路径 主要用于mapper类和mapper.xml不在同一个路径下
  mapper-locations: classpath*:com/hxx/demo_admin/dao/mapper/*.xml
  # 指定POJO扫描包 用于:mapper.xml文件中resultMap的type或者parameterType使用自定义的pojo
  type-aliases-package: com.hxx.demo_admin.dao.pojo

## 日志配置  ##
logging:
  level:
    com.hxx.demo_admin: debug
    org.springframework: warn

3.pojo

package com.hxx.demo_admin.dao.pojo;

import lombok.Data;

import java.io.Serializable;

/**
 * @author hxx
 * @version 1.0
 * @date 2021/5/14 15:02
 */
@Data
public class Test implements Serializable {

    private Long id;
    private String name;
    private int age;

}

4.dao层

/**
 * @author hxx
 * @version 1.0
 * @date 2021/5/14 15:10
 */
@Repository
public interface TestMapper {

    public List<Test> findAll();
}

<?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.hxx.demo_admin.dao.mapper.TestMapper">
    <sql id="base_sql">
         a.id as  id,
         a.name as  name,
         a.age as  age
    </sql>

    <select id="findAll" resultType="com.hxx.demo_admin.dao.pojo.Test">
        select
        <include refid="base_sql"/>
        from
        test a
    </select>
</mapper>

5.启动访问即可哦