新增mybaits的依赖
在 pom.xml中新增 mybatis 和mysql 的依赖,并使用maven 进行同步下载依赖:
<dependency> <groupId>org.mybatis.spring.boot</groupId> <artifactId>mybatis-spring-boot-starter</artifactId> <version>2.1.4</version> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> </dependency>
新增配置项
在application.properties文件中新增mysql和mybaits的配置项:
server.port=9090 # 扫描mapper xml配置项 mybatis.mapper-locations=classpath:mapper/*Mapper.xml # 自动填装entity mybatis.type-aliases-package=com.example.entity spring.datasource.username=root spring.datasource.password=123456 spring.datasource.url=jdbc:mysql://127.0.0.1:3306/test?useUnicode=true&characterEncoding=utf-8&useSSL=true&serverTimezone=UTC spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
注意,mysql8 只能使用com.mysql.cj.jdbc.Driver.
新增测试表:
CREATE TABLE \`user_list\` ( \`id\` int(32) NOT NULL AUTO_INCREMENT, \`userName\` varchar(32) NOT NULL, \`passWord\` varchar(50) NOT NULL, \`realName\` varchar(32) DEFAULT NULL, PRIMARY KEY (\`id\`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8;
新增相关类:
controller 控制器,用于接收数据并调用servie响应,
entity 实体类,每一条数据都会对应成一个相应的类,
mapper, 映射接口,用于定义映射数据的sql语句操作
service,服务层,用于实现接口的方法.
controller:
package com.example.tioncico.controller; import com.example.tioncico.entity.User; import com.example.tioncico.service.UserService; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.web.bind.annotation.PathVariable; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RestController; @RestController @RequestMapping("/user") public class UserController { @Autowired private UserService userService; @RequestMapping("get/{id}") public User get(@PathVariable int id){ return userService.get(id); } }
service:
package com.example.tioncico.service; import com.example.tioncico.entity.User; import com.example.tioncico.mapper.UserMapper; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Service; @Service public class UserService { @Autowired UserMapper userMapper; public User get(int id){ return userMapper.get(id); } }
entity:
package com.example.tioncico.entity; public class User { private Integer id; private String userName; private String passWord; private String realName; public Integer getId() { return id; } public void setId(Integer id) { this.id = id; } public String getUserName() { return userName; } public void setUserName(String userName) { this.userName = userName; } public String getPassWord() { return passWord; } public void setPassWord(String passWord) { this.passWord = passWord; } public String getRealName() { return realName; } public void setRealName(String realName) { this.realName = realName; } @Override public String toString() { return "User{" + "id=" + id + ", userName='" + userName + '\\'' + ", passWord='" + passWord + '\\'' + ", realName='" + realName + '\\'' + '}'; } }
mapper:
package com.example.tioncico.mapper; import com.example.tioncico.entity.User; import org.springframework.stereotype.Repository; @Repository public interface UserMapper { User get(int id); }
启动类注入mapper扫描配置:
package com.example.tioncico; import org.mybatis.spring.annotation.MapperScan; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; import org.springframework.boot.builder.SpringApplicationBuilder; import org.springframework.boot.web.servlet.support.SpringBootServletInitializer; //springboot 应用启动类的标识 @SpringBootApplication //继承SpringBootServletInitializer 用于springboot内部启动tomcat,并且可自定义端口号,项目名 @MapperScan("com.example.tioncico.mapper") //扫描mapper类 public class TioncicoApplication extends SpringBootServletInitializer { public static void main(String\[\] args) { SpringApplication.run(TioncicoApplication.class, args); } @Override protected SpringApplicationBuilder configure(SpringApplicationBuilder builder) { return builder.sources(this.getClass()); } }
在resources文件夹中新增mapper.xml配置项:
注意要和 application.properties在 mybatis.mapper-location 的配置项一致
<?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.example.tioncico.mapper.UserMapper"> <resultMap id="BaseResultMap" type="com.example.tioncico.entity.User"> <result column="id" jdbcType="INTEGER" property="id" /> <result column="userName" jdbcType="VARCHAR" property="userName" /> <result column="passWord" jdbcType="VARCHAR" property="passWord" /> <result column="realName" jdbcType="VARCHAR" property="realName" /> </resultMap> <select id="get" resultType="com.example.tioncico.entity.User"> select * from user_list where id = #{id} </select> </mapper>
项目结构为:
新增一条数据插入到表中:
INSERT INTO user_list (\`id\`,\`userName\`,\`passWord\`,\`realName\`)VALUES(1,"仙士可","123456","666");
访问
http://127.0.0.1:9090/user/get/1
即可看到输出:
注解 sql 语句实现sql操作
package com.example.tioncico.mapper; import com.example.tioncico.entity.User; import org.apache.ibatis.annotations.*; import org.springframework.stereotype.Repository; import java.util.List; @Repository public interface UserMapper { // @Select("select * from user_list where id=#{id}") User get(int id); @Insert({"insert into user_list(userName,passWord,realName) values(#{userName},#{passWord},#{realName})"}) @SelectKey(statement = "select last\_insert\_id()", keyProperty = "id", before = false, resultType = Integer.class) Integer add(User user); @Select("select * from user_list where userName like concat('%',#{userName},'%')") List <User> getListByUserName(String userName); @Update("update user_list set userName=#{userName},passWord=#{passWord},realName=#{realName} where id=#{id}") Integer update(User user); @Delete("delete from user_list where id = #{id}") Integer delete(int id); }
