环境

1 MySQL

2 Spring Tool Suite ，和Eclipse操作差不多，但是不推荐用Eclipse

构建项目（第一种方式：无***Mapper.xml）

新建项目

File ----->New ----->Spring Starter Project

生成的pom.xml如下所示

复制
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
	<modelVersion>4.0.0</modelVersion>
	<parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>1.5.18.RELEASE</version>
		<relativePath/> <!-- lookup parent from repository -->
	</parent>
	<groupId>com.example</groupId>
	<artifactId>demo</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<name>MyBatisDemo2</name>
	<description>Demo project for Spring Boot</description>
 
	<properties>
		<java.version>1.8</java.version>
	</properties>
 
	<dependencies>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-web</artifactId>
		</dependency>
		<dependency>
			<groupId>org.mybatis.spring.boot</groupId>
			<artifactId>mybatis-spring-boot-starter</artifactId>
			<version>1.3.2</version>
		</dependency>
 
		<dependency>
			<groupId>mysql</groupId>
			<artifactId>mysql-connector-java</artifactId>
			<scope>runtime</scope>
		</dependency>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-test</artifactId>
			<scope>test</scope>
		</dependency>
	</dependencies>
 
	<build>
		<plugins>
			<plugin>
				<groupId>org.springframework.boot</groupId>
				<artifactId>spring-boot-maven-plugin</artifactId>
			</plugin>
		</plugins>
	</build>
 
</project>

修改下面的application配置文件

复制
######################################
###spring datasource
######################################
spring.datasource.url=jdbc:mysql://47.105.132.96:3306/trainproject
spring.datasource.username=admin
spring.datasource.password=admin
spring.datasource.driver-class-name=com.mysql.jdbc.Driver

创建实体类

复制
package com.example.demo;
 
public class UserType {
 
	private Integer id;
 
	private String name;
 
	public Integer getId() {
		return id;
	}
 
    //getter  setter  构造方法  toString
 
}

编写mapper层，就是dao层（敲黑板，重点来了）

添加注解@Mapper

在方法上添加注解，根据你的需求，这里以select为例子

希望在操作的时候实体类和数据库字段名一致，可以减少一些古怪的错误

复制
package com.example.demo;
 
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Select;
 
@Mapper
public interface UserTypeMapper {
	
	@Select("select id,name from userType where id = #{id}")
	public UserType selectById(Integer id);
 
}

编写控制层Controller

将mapper注入到controller中，访问/hello会在控制台打印选择的信息

复制
package com.example.demo;
 
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
 
@Controller
public class HelloController {
	
	@Autowired
	private UserTypeMapper userTypeMapper;
	
	@RequestMapping("/hello")
	@ResponseBody
	public String hello(){
		System.out.println(userTypeMapper);
		System.out.println(userTypeMapper.selectById(1));
		return "hello";
	}
 
}

运行项目名称的类

构建项目（第二种方式：有***Mapper.xml）

注意mapper.xml的位置，注意mapper.xml的位置，注意mapper.xml的位置

修改application.properties配置文件

复制
######################################
###spring datasource
######################################
spring.datasource.url=jdbc:mysql://47.105.132.96:3306/trainproject
spring.datasource.username=root
spring.datasource.password=123456
spring.datasource.driver-class-name=com.mysql.jdbc.Driver
 
 
######################################
###MyBatis
######################################
mybatis.mapper-locations=classpath:mapper/*Mapper.xml 

UserTypeMapper层

复制
package com.example.demo;
 
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Select;
 
@Mapper
public interface UserTypeMapper {
	
	
	public UserType selectById(Integer id);
 
}

运行结果