springboot+mybatis数据源配置_<select id="countdevice" parametertype="com.spring-优快云博客

本文链接：https://blog.youkuaiyun.com/pingchangmile/article/details/107669498

上篇已经简单的搭建一个“纯净版”的springboot，压缩包链接地址：https://download.youkuaiyun.com/download/pingchangmile/12670254

今天说下springboot和数据库交互的一些配置

先看下项目的文件结构

首先要先添加在pom中jar包

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid-spring-boot-starter</artifactId>
            <version>1.1.10</version>
        </dependency>
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>1.3.2</version>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>

前3个是对应springboot和mybatis的jar包，最后一个lombok的jar，是为了让他自动生成实体类的get/set方法

这时候，只要jar对应的行不报错，引入的jar没问题，那么就成功一大步了

然后配置properties文件，配置代码如下：

#数据库驱动器名称
spring.datasource.driver-class-name=com.mysql.jdbc.Driver
#数据库链接url
spring.datasource.url=jdbc:mysql://ip或域名:3306/数据库名称?serverTimezone=Asia/Shanghai&allowMultiQueries=true&useUnicode=true&characterEncoding=UTF-8&useSSL=false
#账户名称
spring.datasource.username=用户名
#密码
spring.datasource.password=密码
#数据库连接池
spring.datasource.type=com.alibaba.druid.pool.DruidDataSource

#定义mapper位置的属性 实现mapper接口配置见mapper和接口的绑定
mybatis.mapper-locations=classpath*:mapping/*.xml

这时候配置信息已经完成，剩下的就是写业务逻辑，特别注意注解问题

不多说了，贴上模拟的业务代码

controller层

package com.study.demo.controller;


import com.study.demo.model.TestDO;
import com.study.demo.service.TestService;
import org.springframework.web.bind.annotation.RequestMapping;

import org.springframework.web.bind.annotation.RestController;

import javax.annotation.Resource;

/**
 * <p>
 * 前端控制器
 * </p>
 *
 * @author
 * @since 2020-07-28
 */
@RestController
@RequestMapping("/test")
public class TestController {

    @Resource
    private TestService testService;


    /**
     * 增加
     *
     * @param dto
     */
    @RequestMapping("/add")
    public void add(TestDO dto) {
        int i = testService.insert(dto);

    }

    /**
     * 删除
     *
     * @param id
     */
    @RequestMapping("/delete")
    public void delete(int id) {
        int i = testService.deleteById(id);

    }

    /**
     * 修改
     *
     * @param dto
     */
    @RequestMapping("/update")
    public void update(TestDO dto) {
        int i = testService.update(dto);

    }

    /**
     * 查询
     *
     * @param dto
     * @return
     */
    @RequestMapping("/get")
    public TestDO get(TestDO dto) {
        return testService.selectOne(dto);

    }
}

service层

package com.study.demo.service;

import com.study.demo.model.TestDO;

/**
 * <p>
 *  服务类
 * </p>
 *
 * @author 
 * @since 2020-07-28
 */
public interface TestService {

    int insert(TestDO dto);

    int deleteById(int id);

    int update(TestDO dto);

    TestDO selectOne(TestDO dto);
}

service的实现层impl

package com.study.demo.service.impl;

import com.study.demo.mapper.TestMapper;
import com.study.demo.model.TestDO;
import com.study.demo.service.TestService;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 
 * @since 2020-07-28
 */
@Service
public class TestServiceImpl implements TestService {

    @Resource
    private TestMapper testMapper;
    @Override
    public int insert(TestDO dto) {
        return testMapper.insert(dto);
    }

    @Override
    public int deleteById(int id) {
        return testMapper.deleteById(id);
    }

    @Override
    public int update(TestDO dto) {
        return testMapper.update(dto);
    }

    @Override
    public TestDO selectOne(TestDO dto) {
        return testMapper.selectOne(dto);
    }
}

mapper层

package com.study.demo.mapper;

import com.study.demo.model.TestDO;
import org.apache.ibatis.annotations.Mapper;

/**
 * <p>
 *  Mapper 接口
 * </p>
 *
 * @author 
 * @since 2020-07-28
 */
@Mapper
public interface TestMapper {

    int insert(TestDO dto);

    int deleteById(int id);

    int update(TestDO dto);

    TestDO selectOne(TestDO dto);
}

maper.xml文件

<?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.study.demo.mapper.TestMapper">

    <!-- 通用查询映射结果 -->
    <resultMap id="BaseResultMap" type="com.study.demo.model.TestDO">
		    <id column="id" property="id" />
	        <result column="name" property="name" />
	        <result column="age" property="age" />
    </resultMap>
	    <!-- 通用查询结果列 -->
	<sql id="Base_Column_List">
	     t.id,t.name,t.age
	</sql>
	<!-- 新增 -->
	<insert id="insert" parameterType="com.study.demo.model.TestDO" keyProperty="id" useGeneratedKeys="true">
		insert into test 
			(name,age)
		values 
			(#{name} ,#{age} )
	</insert>
	<!-- 修改 -->
	<update id="update" parameterType="com.study.demo.model.TestDO">
		update test t
		<set>
				<if test="id != null">t.id = #{id},</if>
				<if test="name != null and name != ''">t.name = #{name},</if>
				<if test="age != null">t.age = #{age},</if>
		</set>
		<where>
		   id = #{id}
		</where>
	</update>
	<!-- 查询 -->
	<select id="selectPage" parameterType="com.study.demo.model.TestDO" resultMap="BaseResultMap">
		select <include refid="Base_Column_List"></include> from test t
		<where>
				<if test="id != null"> and  t.id = #{id}</if>
				<if test="name != null and name != ''"> and  t.name = #{name}</if>
				<if test="age != null"> and  t.age = #{age}</if>
		</where>
	</select>
	
	<select id="selectCount" parameterType="com.study.demo.model.TestDO" resultType="Integer">
		select count(1) from test t
		<where>
				<if test="id != null"> and  t.id = #{id}</if>
				<if test="name != null and name != ''"> and  t.name = #{name}</if>
				<if test="age != null"> and  t.age = #{age}</if>
		</where>
	</select>
	
	<select id="selectOne" parameterType="java.util.HashMap" resultMap="BaseResultMap">
		select <include refid="Base_Column_List"></include> from test t
		<where>
				<if test="id != null"> and t.id = #{id}</if>
				<if test="name != null and name != ''"> and t.name = #{name}</if>
				<if test="age != null"> and t.age = #{age}</if>
		</where>
	</select>
	
	<select id="selectById" resultMap="BaseResultMap">
		select <include refid="Base_Column_List"></include> from test t
		<where>
			id = #{0}
		</where>
	</select>
</mapper>

实体类

package com.study.demo.model;

import lombok.Data;

import java.io.Serializable;

/**
 * <p>
 * 
 * </p>
 *
 * @author 
 * @since 2020-07-28
 */

@Data
public class TestDO implements Serializable {

    /** */
    private Integer id;
    /** 名称*/
    private String name;
    /** 年龄*/
    private Integer age;
}

一旦配置完成，可以通过postman等软件检测可行