Spring Boot2.x-07Spring Boot2.1.2整合Mybatis

小小工匠

发布于 2021-08-17 15:48:12

3190

文章被收录于专栏：小工匠聊架构小工匠聊架构

文章目录

概述

废话不多说了，直接撸吧 ,先看看整体的结构【 Spring Boot 2.1.2 , MyBatis 1.3.2 , Mysql 8.0.13 】

搭建Spring Boot工程 Version 2.1.2.RELEASE

pom.xml

<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>4.0.0modelVersion>
	<parent>
		<groupId>org.springframework.bootgroupId>
		<artifactId>spring-boot-starter-parentartifactId>
		<version>2.1.2.RELEASEversion>
		<relativePath /> 
	parent>
	<groupId>com.artisangroupId>
	<artifactId>springbootMybatisartifactId>
	<version>0.0.1-SNAPSHOTversion>
	<name>springbootMybatisname>
	<description>Artisan description>

	<properties>
		<project.build.sourceEncoding>UTF-8project.build.sourceEncoding>
		<project.reporting.outputEncoding>UTF-8project.reporting.outputEncoding>
		<java.version>1.8java.version>
	properties>

	<dependencies>

		
		<dependency>
			<groupId>org.springframework.bootgroupId>
			<artifactId>spring-boot-starter-webartifactId>
		dependency>

		
		<dependency>
			<groupId>org.springframework.bootgroupId>
			<artifactId>spring-boot-starter-jdbcartifactId>
		dependency>

		
		<dependency>
			<groupId>mysqlgroupId>
			<artifactId>mysql-connector-javaartifactId>
		dependency>

		
		<dependency>
			<groupId>org.mybatis.spring.bootgroupId>
			<artifactId>mybatis-spring-boot-starterartifactId>
			<version>1.3.2version>
		dependency>

		
		<dependency>
			<groupId>org.projectlombokgroupId>
			<artifactId>lombokartifactId>
		dependency>

		
		<dependency>
			<groupId>org.springframework.bootgroupId>
			<artifactId>spring-boot-devtoolsartifactId>
			<optional>trueoptional>
		dependency>

		
		<dependency>
			<groupId>org.springframework.bootgroupId>
			<artifactId>spring-boot-starter-testartifactId>
			<scope>testscope>
		dependency>
	dependencies>

	<build>
		<plugins>
			<plugin>
				<groupId>org.springframework.bootgroupId>
				<artifactId>spring-boot-maven-pluginartifactId>
			plugin>
		plugins>
	build>

project>

pom中每个jar包都加了注释，这里就不啰嗦了。

application.yml 数据库的配置

# datasource
spring:
  datasource:
    driver-class-name: com.mysql.cj.jdbc.Driver # JDBC连接Mysql6以上com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://localhost:3306/artisan?serverTimezone=UTC&useUnicode=true&characterEncoding=utf8&useSSL=false
    username: root
    password: root

通过上面的属性配置数据库的连接信息后， Spring Boot 就可以自动配置数据源了

集成Mybatis

Step1 添加依赖mybatis- spring-boot- starter

刚才的pom中已经有了，如下

	<!-- mybatis的starter -->
		<dependency>
			<groupId>org.mybatis.spring.boot</groupId>
			<artifactId>mybatis-spring-boot-starter</artifactId>
			<version>1.3.2</version>
		</dependency>

Step2 库表及domain类

为了方便演示，新建库表和对应的实体类

-- ----------------------------
-- Table structure for artisan
-- ----------------------------
DROP TABLE IF EXISTS `artisan`;
CREATE TABLE `artisan` (
  `id` int(9) NOT NULL AUTO_INCREMENT,
  `name` varchar(255) DEFAULT NULL,
  `sex` varchar(255) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=6 DEFAULT CHARSET=utf8;



-- ----------------------------
-- Records of artisan
-- ----------------------------
INSERT INTO `artisan` VALUES ('1', 'artisan', '男');
INSERT INTO `artisan` VALUES ('2', '程序媛', '女');
INSERT INTO `artisan` VALUES ('3', '周杰伦', '男');
INSERT INTO `artisan` VALUES ('4', '小笼包', '女');
INSERT INTO `artisan` VALUES ('5', '巨石强森', '男');

com.artisan.model包下新建Artisan实体类

package com.artisan.model;

import lombok.Data;

/**
 * 
 * @author yangshangwei
 * 
 *         lombok的注解 @Data 注解在类上 提供类所有属性的 getting 和 setting 方法，
 *         此外还提供了equals、canEqual、hashCode、toString 方法
 *
 */
@Data
public class Artisan {

	private Long id;
	private String name;
	private String sex;

}

Step3 添加ArtisanMapper接口

com.artisan.mapper包下新建接口 ArtisanMapper

package com.artisan.mapper;

import java.util.List;

import org.apache.ibatis.annotations.Mapper;

import com.artisan.model.Artisan;
/**
 * 
 * @author yangshangwei
 *	
 * 增加@Mapper这个注解之后，Spring 启动时会自动扫描该接口，这样就可以在需要使用时直接注入 Mapper 了
 */

@Mapper
public interface ArtisanMapper {
	
	/**
	 *  查询全部数据
	 */
	List<Artisan> selectArtisan();
	
}

使用了＠ Mapper 注解，增加这个注解之后，Spring 启动时会自动扫描该接口，这样就可以在需要使用时直接注入 Mapper 了

Step4 添加SQL映射文件

在 src/main/resources下面创建mapper目录，然后新建 ArtisanMapper.xml映射文件

<mapper namespace="com.artisan.mapper.ArtisanMapper">
	<select id="selectArtisan" resultType="Artisan"> 
		select id , name ,sex from artisan
	select>
mapper>

Step5 application.yml中配置mybatis

增加如下Mybatis的配置

#mybatis    
mybatis:
  # 映射文件的路径 ，支持 Ant 风格的通配符， 多个配置可以使用英文逗号隔开
  mapper-locations: classpath:mapper/*.xml  
  # 类型别名包画配置，只能指定具体的包，多个配置可以使用英文逗号隔开
  type-aliases-package: com.artisan.model
  # Mybatis SQL语句控制台打印
  configuration: 
      log-impl: org.apache.ibatis.logging.stdout.StdOutImpl

Step6 Service层编写

接口和实现类

package com.artisan.service;

import java.util.List;

import com.artisan.model.Artisan;

public interface ArtisanService {
	
	List<Artisan> getArtisanList();
}

package com.artisan.service.impl;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import com.artisan.mapper.ArtisanMapper;
import com.artisan.model.Artisan;
import com.artisan.service.ArtisanService;

@Service
public class ArtisanServiceImpl implements ArtisanService {
	
	@Autowired
	private ArtisanMapper artisanMapper;
	
	@Override
	public List<Artisan> getArtisanList() {
		return artisanMapper.selectArtisan();
	}

}

Step7 约定后台返回规范（可省略）

使用泛型封装下返回结果，见注释。第二个包装类CodeMsg 用了lombok的注解，可以不用。Result没用，仅仅是演示下。。。

package com.artisan.result;

public class Result<T> {
	private int code;
	private String msg;
	private T data;

	/**
	 * 成功时候的调用
	 * */
	public static <T> Result<T> success(T data){
		return new  Result<T>(data);
	}
	
	/**
	 * 失败时候的调用
	 * */
	public static <T> Result<T> error(CodeMsg cm){
		return new  Result<T>(cm);
	}
	
	private Result(T data) {
		this.code = 0;
		this.msg = "success";
		this.data = data;
	}
	
	private Result(CodeMsg cm) {
		if(cm == null) {
			return;
		}
		this.code = cm.getCode();
		this.msg = cm.getMsg();
	}

	public int getCode() {
		return code;
	}
	public String getMsg() {
		return msg;
	}
	public T getData() {
		return data;
	}
}

package com.artisan.result;

import lombok.Getter;

public class CodeMsg {

	@Getter
	private int code;
	@Getter
	private String msg;

	// 通用异常
	public static CodeMsg SUCCESS = new CodeMsg(0, "success");
	public static CodeMsg SERVER_ERROR = new CodeMsg(-1, "服务端异常");

	private CodeMsg(int code, String msg) {
		this.code = code;
		this.msg = msg;
	}

}

Step8 Controller编写

package com.artisan.controller;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

import com.artisan.model.Artisan;
import com.artisan.result.CodeMsg;
import com.artisan.result.Result;
import com.artisan.service.ArtisanService;

@RestController
public class ArtisanController {
	
	@Autowired
	private ArtisanService artisanService;
	
	@GetMapping("/test")
	public String test() {
		return "artisan test";
	}
	
	// 正常情况
	@GetMapping("/artisans")
	public Result<List<Artisan>> selectAllArtisan() {
		return Result.success(artisanService.getArtisanList());
	}
	
	
	// 模拟异常情况
	@GetMapping("/artisansError")
	public Result<List<Artisan>> selectAllArtisanError() {
		return Result.error(CodeMsg.SERVER_ERROR);
	}
	
}