SpringBoot + Vue前后端分离项目实战 || 二：Spring Boot后端与数据库连接

系列文章：
SpringBoot + Vue前后端分离项目实战 || 一：Vue前端设计
SpringBoot + Vue前后端分离项目实战 || 二：Spring Boot后端与数据库连接
SpringBoot + Vue前后端分离项目实战 || 三：Spring Boot后端与Vue前端连接
SpringBoot + Vue前后端分离项目实战 || 四：用户管理功能实现
SpringBoot + Vue前后端分离项目实战 || 五：用户管理功能后续

B站视频讲解：2023全网最简单但实用的SpringBoot+Vue前后端分离项目实战

不想看视频可浏览此文章笔记，比较详细

新建Spring后台项目

IDEA file->new->project

选择 Spring Initializr

此处不加依赖，直接FINISH

添加依赖

首先确认本地maven已经配置好，点击File -> Settings 查看Maven

找到pom.xml文件

直接复制此处需要的依赖

<?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 https://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>2.7.8</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.ums</groupId>
    <artifactId>x-admin</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>x-admin</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</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>

        <!-- web -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <!-- mysql -->
        <dependency>
            <groupId>com.mysql</groupId>
            <artifactId>mysql-connector-j</artifactId>
        </dependency>
        <!-- mybatis-plus -->
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>3.5.2</version>
        </dependency>
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-generator</artifactId>
            <version>3.5.2</version>
        </dependency>
        <!-- freemarker -->
        <dependency>
            <groupId>org.freemarker</groupId>
            <artifactId>freemarker</artifactId>
        </dependency>
        <!-- lombok -->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-redis</artifactId>
            <version>2.2.5.RELEASE</version>
        </dependency>

        <!-- fastjson -->
        <dependency>
            <groupId>com.alibaba.fastjson2</groupId>
            <artifactId>fastjson2</artifactId>
            <version>2.0.7</version>
        </dependency>

    </dependencies>

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

</project>

遇到爆红，点击右侧Maven中刷新按钮，等待IDEA下载依赖即可，多刷新几次，等待

新建数据库

用navicat链接本地数据库，新建一个数据库xdb

新建一个 123.txt 文档，将以下SQL命令复制进去后，改名为123.sql

CREATE TABLE `x_user` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `username` varchar(50) NOT NULL,
  `password` varchar(100) DEFAULT NULL,
  `email` varchar(50) DEFAULT NULL,
  `phone` varchar(20) DEFAULT NULL,
  `status` int(1) DEFAULT NULL,
  `avatar` varchar(200) DEFAULT NULL,
   `deleted` INT(1) DEFAULT 0,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=3 DEFAULT CHARSET=utf8;

insert into `x_user` (`id`, `username`, `password`, `email`, `phone`, `status`, `avatar`, `deleted`) values('1','admin','123456','[email protected]','18677778888','1','https://wpimg.wallstcn.com/f778738c-e4f8-4870-b634-56703b4acafe.gif','0');
insert into `x_user` (`id`, `username`, `password`, `email`, `phone`, `status`, `avatar`, `deleted`) values('2','zhangsan','123456','[email protected]','13966667777','1','https://wpimg.wallstcn.com/f778738c-e4f8-4870-b634-56703b4acafe.gif','0');
insert into `x_user` (`id`, `username`, `password`, `email`, `phone`, `status`, `avatar`, `deleted`) values('3','lisi','123456','[email protected]','13966667778','1','https://wpimg.wallstcn.com/f778738c-e4f8-4870-b634-56703b4acafe.gif','0');
insert into `x_user` (`id`, `username`, `password`, `email`, `phone`, `status`, `avatar`, `deleted`) values('4','wangwu','123456','[email protected]','13966667772','1','https://wpimg.wallstcn.com/f778738c-e4f8-4870-b634-56703b4acafe.gif','0');
insert into `x_user` (`id`, `username`, `password`, `email`, `phone`, `status`, `avatar`, `deleted`) values('5','zhaoer','123456','[email protected]','13966667776','1','https://wpimg.wallstcn.com/f778738c-e4f8-4870-b634-56703b4acafe.gif','0');
insert into `x_user` (`id`, `username`, `password`, `email`, `phone`, `status`, `avatar`, `deleted`) values('6','songliu','123456','[email protected]','13966667771','1','https://wpimg.wallstcn.com/f778738c-e4f8-4870-b634-56703b4acafe.gif','0');

CREATE TABLE `x_role` (
  `role_id` int(11) NOT NULL AUTO_INCREMENT,
  `role_name` varchar(50) DEFAULT NULL,
  `role_desc` varchar(100) DEFAULT NULL,
  PRIMARY KEY (`role_id`)
) ENGINE=InnoDB AUTO_INCREMENT=4 DEFAULT CHARSET=utf8mb4;

insert into `x_role` (`role_id`, `role_name`, `role_desc`) values('1','admin','超级管理员');
insert into `x_role` (`role_id`, `role_name`, `role_desc`) values('2','hr','人事专员');
insert into `x_role` (`role_id`, `role_name`, `role_desc`) values('3','normal','普通员工');

CREATE TABLE `x_menu` (
  `menu_id` int(11) NOT NULL AUTO_INCREMENT,
  `component` varchar(100) DEFAULT NULL,
  `path` varchar(100) DEFAULT NULL,
  `redirect` varchar(100) DEFAULT NULL,
  `name` varchar(100) DEFAULT NULL,
  `title` varchar(100) DEFAULT NULL,
  `icon` varchar(100) DEFAULT NULL,
  `parent_id` int(11) DEFAULT NULL,
  `is_leaf` varchar(1) DEFAULT NULL,
  `hidden` tinyint(1) DEFAULT NULL,
  PRIMARY KEY (`menu_id`)
) ENGINE=InnoDB AUTO_INCREMENT=12 DEFAULT CHARSET=utf8mb4;

insert  into `x_menu`(`menu_id`,`component`,`path`,`redirect`,`name`,`title`,`icon`,`parent_id`,`is_leaf`,`hidden`) values (1,'Layout','/user','/user/list','userManage','用户管理','userManage',0,'N',0),(2,'user/user','list',NULL,'userList','用户列表','userList',1,'Y',0),(3,'user/role','role',NULL,'roleList','角色列表','role',1,'Y',0),(4,'user/permission','permission',NULL,'permissionList','权限列表','permission',1,'Y',0);

CREATE TABLE `x_user_role` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `user_id` int(11) DEFAULT NULL,
  `role_id` int(11) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=5 DEFAULT CHARSET=utf8mb4;

insert into `x_user_role` (`id`, `user_id`, `role_id`) values('1','1','1');

CREATE TABLE `x_role_menu` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `role_id` int(11) DEFAULT NULL,
  `menu_id` int(11) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=5 DEFAULT CHARSET=utf8mb4;

右击xdb选择运行SQL文件

找到123.sql文件后运行

运行成功

IDEA 连接数据库

打开src\main\resources\application.yml，如果没有该文件，只有application.property文件，则直接改其后缀为.yml

写入代码

server:
  port: 9999            # 端口号
spring:
  datasource:
    username: root      # 数据库名
    password: 1234      # 数据库密码
    url: jdbc:mysql:///xdb

  redis:
    port: 6379
    host: localhost

logging:
  level:
    com.ums: debug

IDEA 自动创建类实体

先新建一个package:sys，空包，生成的代码会放在此处

用Mybatis-plus来自动创建类实体的java代码
在src\test下新建一个java类：CodeGenerator

然后写上如下代码，代码中有解释

package com.ums;

import com.baomidou.mybatisplus.generator.FastAutoGenerator;
import com.baomidou.mybatisplus.generator.config.OutputFile;
import com.baomidou.mybatisplus.generator.engine.FreemarkerTemplateEngine;

import java.util.Collections;

public class CodeGenerator {
    
    
    public static void main(String[] args) {
    
    
        String url = "jdbc:mysql:///xdb";       // 与配置文件 一致
        String username = "root";
        String password = "1234";
        String author = "anthony";
        String moduleName = "sys";              // 系统管理的代码包
        String mapperLocation = "D:\\VueProj\\x-admin\\src\\main\\resources\\mapper\\" + moduleName ;
        String tables = "x_menu,x_role,x_role_menu,x_user,x_user_role";     // 与数据库中的表名一致，逗号隔开

        FastAutoGenerator.create(url, username, password)
            .globalConfig(builder -> {
    
    
                builder.author(author) // 设置作者
//                        .enableSwagger() // 开启 swagger 模式
//                        .fileOverride() // 覆盖已生成文件
                        .outputDir("D:\\VueProj\\x-admin\\src\\main\\java"); // 指定输出目录
            })

            .packageConfig(builder -> {
    
    
                builder.parent("com.ums") // 设置父包名
                        .moduleName(moduleName) // 设置父包模块名
                        .pathInfo(Collections.singletonMap(OutputFile.xml, mapperLocation)); // 设置mapperXml生成路径
            })
            .strategyConfig(builder -> {
    
    
                builder.addInclude(tables) // 设置需要生成的表名
                        .addTablePrefix("x_"); // 设置过滤表前缀， x_menu 生成的类实体无 x_ 前缀
            })
            .templateEngine(new FreemarkerTemplateEngine()) // 使用Freemarker引擎模板，默认的是Velocity引擎模板
            .execute();
    }
}

点击run

生成代码

定义数据传递至前端的格式

上一节说过，需要记录下前端登录的响应数据格式
现在，后端来构造此格式

{
    
    "code":20000,"data":{
    
    "token":"admin-token"}}

在src\main下新建一个package: common 然后新建package：vo 再新建一个java类Result

写入代码，有注释解释

package com.ums.common.vo;


import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

@Data
@NoArgsConstructor
@AllArgsConstructor
public class Result<T> {
    
    
    private Integer code;       // 成功失败的代码，此处定义2000为成功，2001为失败
    private String message;     // 消息，里面包含数据data
    private T data;             // 未定义的数据形式

    // 此处重载了四个 success 方法，有些能够返回数据，有的只返回代码或信息
    public static <T> Result<T> success() {
    
    
        return new Result<>(20000,"success",null);
    }

    public static <T> Result<T> success(T data) {
    
    
        return new Result<>(20000,"success",data);
    }

    public static <T> Result<T> success(T data, String message) {
    
    
        return new Result<>(20000,message,data);
    }

    public static <T> Result<T> success(String message) {
    
    
        return new Result<>(20000,message,null);
    }

    public static<T>  Result<T> fail(){
    
    
        return new Result<>(20001,"fail",null);
    }

    public static<T>  Result<T> fail(Integer code){
    
    
        return new Result<>(code,"fail",null);
    }

    public static<T>  Result<T> fail(Integer code, String message){
    
    
        return new Result<>(code,message,null);
    }

    public static<T>  Result<T> fail( String message){
    
    
        return new Result<>(20001,message,null);
    }
}

测试

1. 先在主程序src\main\java中的XAdminApplication中加入注解@MapperScan("com.ums.*.mapper")
   
2. 进入UserController写测试代码
   

   package com.ums.sys.controller;
   
   import com.ums.common.vo.Result;
   import com.ums.sys.entity.User;
   import com.ums.sys.service.IUserService;
   import org.springframework.beans.factory.annotation.Autowired;
   import org.springframework.web.bind.annotation.GetMapping;
   import org.springframework.web.bind.annotation.RequestMapping;
   import org.springframework.stereotype.Controller;
   import org.springframework.web.bind.annotation.RestController;
   
   import java.util.List;
   
   /**
    * <p>
    *  前端控制器
    * </p>
    *
    * @author anthony
    * @since 2023-06-16
    */
   @RestController
   @RequestMapping("/user")
   public class UserController {
         
         
       @Autowired
       private IUserService userService;
   
       @GetMapping("/all")
       public Result<List<User>> getAllUser() {
         
         
           List<User> list = userService.list();
           return Result.success(list,"查询成功");
       }
   }
   

3. 运行主程序
   
   进入浏览器输入http://localhost:9999/user/all 显示数据则成功
   
   此处数据格式也与前端对接得上