1、下载安装一个Mysql数据库及管理工具，同类工具很多，随便找一个都可以，我在windows下做测试项目习惯使用的是haosql
它内部集成了MySql-Front管理工具
2、创建一个j_user表，有如下列，先设计几个常用列，以后有需要再扩展字段
3、打开mybatis官网可以查看资料
http://www.mybatis.org/mybatis-3/zh/getting-started.html
pom.xml中添加mybatis和mysql
<!-- https://mvnrepository.com/artifact/org.mybatis/mybatis -->
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>3.5.3</version>
</dependency>
<!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java -->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.18</version>
</dependency>
4、安装一个插件,可以自动生成setter,getter
引入依赖
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<optional>true</optional>
</dependency>
5、添加一个数据库连接，
本地mysql版本5.7,使用高版本驱动提示时区错误，改为MySql For 5.1
或者链接字符串增加?useUnicode=true&characterEncoding=utf8&serverTimezone=GMT%2B8&useSSL=false
6、添加一个插件
7、连接数据库生成代码
8、结构如下
修改JUserDao.xml
或者修改生成配置，从新生成也行
9、application.properties修改如下
spring.datasource.url = jdbc:mysql://localhost:3306/jgdb
spring.datasource.username = root
spring.datasource.password = ***
spring.datasource.driverClassName = com.mysql.jdbc.Driver
spring.datasource.max-active=20
spring.datasource.max-idle=8
spring.datasource.min-idle=8
spring.datasource.initial-size=10
mybatis.mapper-locations=classpath:mapper/*.xml
mybatis.typeAliasesPackage=com.jgui.mapper
10、修改pom.xml，build下确保有如下代码
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
<resources>
<resource>
<directory>src/main/java</directory>
<includes>
<include>**/*.properties</include>
<include>**/*.xml</include>
</includes>
<filtering>false</filtering>
</resource>
<resource>
<directory>src/main/resources</directory>
<includes>
<include>**/*.properties</include>
<include>**/*.xml</include>
</includes>
<filtering>false</filtering>
</resource>
</resources> </build>
11、JUserDao下增加@Mapper
12、启动文件增加MappScan，上一步和此处任做一个即可。
package com.jgui; import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@MapperScan({ "com.jgui.dao"})
@SpringBootApplication
public class JgadminApplication { public static void main(String[] args) {
SpringApplication.run(JgadminApplication.class, args);
} }
13、为了简单测试，不再建立Services层，直接修改HelloController如下
@RestController
public class HelloController {
@Resource
private JUserDao userDao;
@RequestMapping("/Hello")
public String hello() {
return userDao.selectByPrimaryKey(1).getUsername();
//return "Hello World11";
}
}
14、在浏览器访问
15、经验教训
Invalid bound statement (not found)
No qualifying bean of type 'com.jgui.dao.JUserDao' available
8-12不能遗漏，不然会报上面两个错误！
该项目GITHub的地址：https://github.com/zhaogaojian/jadmin