主要参考:
IDEA2021.2安装与配置(持续更新)使用IDEA搭建一个简单的SpringBoot项目——详细过程

MySql 5.7 +SpringBoot2.7.8 + Maven3.6.3 +IDEA 2018

一.Maven下载和安装

主要参考 Windows安装Maven各版本

1.Maven下载

官网:Maven – Download Apache Maven

下载了3.6.3版本,解压到E盘,新建一个仓库文件夹

2.配置本地仓库

ideamaven搭建ssH框架步骤 idea 创建maven springboot框架_spring

修改为

<localRepository>E:\apache-maven-repository</localRepository>

3.配置远程仓库

依旧是这个文件下的mirrors下面建两个阿里云的远程仓库下载路径 。

<!--阿里远程仓库 -->
    <mirror>
      <id>alimaven</id>
      <name>aliyun maven</name>
      <url>http://maven.aliyun.com/nexus/content/groups/public/</url>
      <mirrorOf>central</mirrorOf>
    </mirror>
    <mirror>
      <id>alimaven</id>
      <mirrorOf>central</mirrorOf>
      <name>aliyun maven</name>
      <url>http://maven.aliyun.com/nexus/content/repositories/central/</url>
    </mirror>

修改完保存。

4.编辑系统变量

新建系统变量MAVEN_HOME

ideamaven搭建ssH框架步骤 idea 创建maven springboot框架_ideamaven搭建ssH框架步骤_02

在Path环境变量下添加Maven的参数 %MAVEN_HOME%\bin

ideamaven搭建ssH框架步骤 idea 创建maven springboot框架_maven_03

5.输入mvn -v查看版本号及安装情况

ideamaven搭建ssH框架步骤 idea 创建maven springboot框架_spring_04

6.然后用idea配置下Maven的路径,配置文件路径,本地仓库路径即可

ideamaven搭建ssH框架步骤 idea 创建maven springboot框架_spring boot_05

二、使用IDEA搭建一个简单的SpringBoot项目

主要参考:使用IDEA搭建一个简单的SpringBoot项目——详细过程

1.创建项目

ideamaven搭建ssH框架步骤 idea 创建maven springboot框架_ideamaven搭建ssH框架步骤_06


ideamaven搭建ssH框架步骤 idea 创建maven springboot框架_ideamaven搭建ssH框架步骤_07


ideamaven搭建ssH框架步骤 idea 创建maven springboot框架_intellij-idea_08

2.Maven仓库的配置

点击右侧的Maven,点击设置(扳手图标)进行Maven仓库的配置

ideamaven搭建ssH框架步骤 idea 创建maven springboot框架_ideamaven搭建ssH框架步骤_09

配置完后,如果没有自动导包,可以点击左上角重新导包按钮,或者呢个下载按钮,选择下载所有源文件和文档

ideamaven搭建ssH框架步骤 idea 创建maven springboot框架_intellij-idea_10

3.新建index.html页面

在templates文件下新建index.html页面,作为启动的初始页面

ideamaven搭建ssH框架步骤 idea 创建maven springboot框架_maven_11

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>hello</title>
</head>
<body>
    你好!初学者,我是SpringBoot的简单启动页面!
</body>
</html>

4.新建controller文件夹

在com.example.test(重建后目录变化)下新建controller文件夹,在controller文件夹下建一个简单的HelloController类;(Controller类要添加@Controller注解,项目启动时,SpringBoot会自动扫描加载Controller

ideamaven搭建ssH框架步骤 idea 创建maven springboot框架_spring_12

package com.miaoshaproject.miaosha.controller;

import org.springframework.web.bind.annotation.RequestMapping;

public class HelloController {
    @RequestMapping("/index")
    public String sayHello() {
        return "index";
    }
    }

5.配置DataSource基本信息

在resources文件夹下application中先配置DataSource基本信息,application文件有两种文件格式,一种是以.properties为后缀,一种是以.yml为后缀的,两种配置方式略有差别,详情可参考这个网址:;在这我是用.yml后缀的文件格式。右键application文件选择Refact,选择Rename,将后缀改为yml;

ideamaven搭建ssH框架步骤 idea 创建maven springboot框架_intellij-idea_13

ideamaven搭建ssH框架步骤 idea 创建maven springboot框架_ideamaven搭建ssH框架步骤_14

6.运行项目启动类

ideamaven搭建ssH框架步骤 idea 创建maven springboot框架_spring_15

7.在浏览器中输入localhost:8080,回车显示初始的index界面

到这项目的初步搭建已经完成,下面可以下一些简单的业务逻辑,比如从数据库获取信息,登录之类的简单功能;

ideamaven搭建ssH框架步骤 idea 创建maven springboot框架_spring boot_16

8.链接数据库

点击右侧的Database,点“加号”,新建数据库链接;

ideamaven搭建ssH框架步骤 idea 创建maven springboot框架_spring_17

链接失败是驱动的问题,点击左上角的小扳手,进入数据库设置界面

ideamaven搭建ssH框架步骤 idea 创建maven springboot框架_maven_18


ideamaven搭建ssH框架步骤 idea 创建maven springboot框架_maven_19

新建user表,再添加字段

ideamaven搭建ssH框架步骤 idea 创建maven springboot框架_maven_20

成功

ideamaven搭建ssH框架步骤 idea 创建maven springboot框架_maven_21

9.SpringBoot项目的分层:

(1)DAO层:包括XxxMapper.java(数据库访问接口类),XxxMapper.xml(数据库链接实现);(这个命名,有人喜欢用Dao命名,有人喜欢用Mapper,看个人习惯了吧) `Xxx.java 一般是定义函数, Xxx.xml 是具体实现(增删改查)

(2)Bean层:也叫model层,模型层,entity层,实体层,就是数据库表的映射实体类,存放POJO对象; 定义变量,与数据库相对应

(3)Service层:也叫服务层,业务层,包括XxxService.java(业务接口类),XxxServiceImpl.java(业务实现类);(可以在service文件夹下新建impl文件放业务实现类,也可以把业务实现类单独放一个文件夹下,更清晰) XxxService.java(业务接口类)和DAO层的Xxx.java类似,都是定义函数,XxxServiceImpl.java(业务实现类)是具体实现

(4)Web层:就是Controller层,实现与web前端的交互。

ideamaven搭建ssH框架步骤 idea 创建maven springboot框架_spring boot_22

10.代码添加

(1)在application配置文件中添加MyBatis配置:
spring:
  datasource:
    name: test  #数据库名
    url: jdbc:mysql://localhost:3306/test?&serverTimezone=Asia/Shanghai
    username: root  #用户名
    password: '123456'  #密码
    driver-class-name: com.mysql.cj.jdbc.Driver
    #数据库链接驱动


mybatis:
  mapper-locations: classpath:mapper/*.xml  #配置映射文件
  type-aliases-package: com.miaoshaproject.miaosha.bean #配置实体类
(2)pom.xml文件配置信息
<?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.miaoshaproject</groupId>
    <artifactId>miaosha</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>miaosha</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>8</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jdbc</artifactId>
        </dependency>

        <!--thymeleaf模板引擎配置-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-thymeleaf</artifactId>
        </dependency>

        <!--Web依赖-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <!--MySQL数据库配置-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.19</version>
        </dependency>

        <!--单元测试配置-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>

        <!--MyBatis配置-->
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>1.3.1</version>
        </dependency>

        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <scope>test</scope>
        </dependency>

    </dependencies>

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

</project>
(3)Bean实体类,依据数据库表,生成set和get方法;
package com.miaoshaproject.miaosha.bean;

public class UserBean {

    private int id;
    private String name;
    private String password;

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }


}
(4)DAO层访问数据库接口文件:
package com.miaoshaproject.miaosha.mapper;

import  com.miaoshaproject.miaosha.bean.UserBean;
import org.apache.ibatis.annotations.Param;
import org.springframework.stereotype.Repository;

@Repository
public interface UserMapper {
    UserBean getInfo(@Param("name")String name, @Param("password")String password);
}
(5)DAO层访问数据库实现文件

需在resource包下创建mapper文件夹,然后再创建一个UserMapper.xml.在application配置文件中mybatis:mapper-locations:对应的就是该文件地址),注意标签的namespace属性要填写 访问数据库接口类文件路径:

<?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.miaoshaproject.miaosha.mapper.UserMapper">
    <select id="getInfo" parameterType="String" resultType="com.miaoshaproject.miaosha.bean.UserBean">
        SELECT * FROM user WHERE name = #{name} AND password = #{password}
    </select>
</mapper>
(6)Service层业务接口类编写:
package com.miaoshaproject.miaosha.service;

import com.miaoshaproject.miaosha.bean.UserBean;

public interface UserService {
    UserBean loginIn(String name, String password);
}
(7)Service层业务实现类编写,注意要注解@Service,注入DAO:
package com.miaoshaproject.miaosha.servicelmpl;

import com.miaoshaproject.miaosha.bean.UserBean;
import com.miaoshaproject.miaosha.mapper.UserMapper;
import com.miaoshaproject.miaosha.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;


@Service
public class UserServicelmpl implements UserService {

    //将DAO注入Service层
    @Autowired
    private UserMapper userMapper;

    @Override
    public UserBean loginIn(String name, String password) {
        return userMapper.getInfo(name,password);
    }
    
}
(8)项目启动类要添加注解@MapperScan项目启动时扫描mapper接口,否则会报错找不到mapper文件:
package com.miaoshaproject.miaosha;

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
@MapperScan("com.miaoshaproject.miaosha.mapper")
public class MiaoshaApplication {

    public static void main(String[] args) {
        SpringApplication.run(MiaoshaApplication.class, args);
    }
}
(9)编写测试类,看是否能成功 访问数据库,获取数据库信息:
package com.miaoshaproject.miaosha;

import com.miaoshaproject.miaosha.bean.UserBean;
import com.miaoshaproject.miaosha.service.UserService;
import org.junit.jupiter.api.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;

@RunWith(SpringRunner.class)
@SpringBootTest
class MiaoshaApplicationTests {

    @Autowired
    UserService userService;

    @Test
    public void contextLoads() {
        UserBean userBean = userService.loginIn("a","a");
        System.out.println("该用户ID为:");
        System.out.println(userBean.getId());
    }
}
(10) controller层,注意添加@controller注解,注入Service服务:
package com.miaoshaproject.miaosha.controller;

import com.miaoshaproject.miaosha.bean.UserBean;
import com.miaoshaproject.miaosha.service.UserService;
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.RequestMethod;


@Controller
public class LoginController {

    //将Service注入Web层
    @Autowired
    UserService userService;

    @RequestMapping("/login")
    public String show(){
        return "login";
    }

    @RequestMapping(value = "/loginIn",method = RequestMethod.POST)
    public String login(String name,String password){
        UserBean userBean = userService.loginIn(name,password);
        if(userBean!=null){
            return "success";
        }else {
            return "error";
        }
    }
}
(11)html文件:

login.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>login</title>
</head>
<body>
<form role="form" action = "/loginIn" method="post">
    账号:<input type="text" id="name" name = "name"> <br>
    密码:<input type="password" id = "password" name = "password"> <br>
    <input type="submit" id = "login" value = "login">
</form>

</body>
</html>

success.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>success</title>
</head>
<body>
<h1>登录成功!</h1>
</body>
</html>

error.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>error</title>
</head>
<body>
    <h1>登录失败!</h1>
</body>
</html>

11.先运行测试类,看是否成功获取数据库信息:

ideamaven搭建ssH框架步骤 idea 创建maven springboot框架_spring boot_23

12.运行TestApplication.java文件,启动项目,无任何WARN警告信息,进入浏览器输入localhost:8080/login

ideamaven搭建ssH框架步骤 idea 创建maven springboot框架_spring_24


ideamaven搭建ssH框架步骤 idea 创建maven springboot框架_intellij-idea_25

三、报错总结

1.Unable to import maven project: See logs for details

ideamaven搭建ssH框架步骤 idea 创建maven springboot框架_spring boot_26

解决:删除项目的.idea文件,选择根项目,然后重新导入项目;

参考:idea Maven报Unable to import maven project: See logs for details解决方法

2.Error:java: 无效的源发行版: 11

解决:修改project settings的配置

ideamaven搭建ssH框架步骤 idea 创建maven springboot框架_ideamaven搭建ssH框架步骤_27

参考:Error:java: 无效的源发行版: 11

3.Error: 类文件具有错误的版本 61.0, 应为 52.0, 请删除该文件或确保该文件位于正确的类路径子目录中。

原因:SpringBoot 3.0 最低要求是 jdkb版本为 17,所以spring-boot-starter-parent需要使用 2.x 的版本,将版本改为2.x以下就可以了

解决:直接修改这两个地方,然后import change

ideamaven搭建ssH框架步骤 idea 创建maven springboot框架_maven_28

参考:java: 无法访问org.springframework.boot.SpringApplication;类文件具有错误的版本 61.0, 应为 52.0

4.MySQL数据库[42000][1049] Unknown database ‘test‘.

解决:数据库创建时名字错误,改正

参考:IDEA连接MySQL数据库[42000][1049] Unknown database ‘logistics‘.

5.数据库建表时报错 [42000][1064] You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ’

解决:用5.7版本的mysql建表语言去建表

参考:MySQL5.7 建库、建表、加字段等常用命令

6.UserServicelmpl 报错Could not autowire. No beans of ‘UserMapper‘ type found

ideamaven搭建ssH框架步骤 idea 创建maven springboot框架_spring_29

解决:在 UserMapper里加入了注解@Repository

参考:idea报“Could not autowire. No beans of ‘UserMapper‘ type found. ”错解决办法

7.测试时报错Caused by: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name ‘userServicelmpl’: Unsatisfied dependency expressed through field ‘userMapper’;

参考:Causedby:org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with

8.IllegalStateException: Cannot load driver class: com.mysql.jdbc.Driver

解决:pom.xml 中的mysql依赖写错

<dependency>
			<groupId>mysql</groupId>
			<artifactId>mysql-connector-java</artifactId>
			<version>8.0.19</version>
		</dependency>

参考:Caused by: java.lang.IllegalStateException: Cannot load driver class: com.mysql.jdbc.Driver

9.org.mybatis.spring.MyBatisSystemException: nested exception is org.apache.ibatis.binding.BindingException: Parameter ‘name’ not found. Available parameters are [arg1, arg0, param1, param2]

原因:mapper映射没有成功接收到参数,需要注意参数传入的写法,多参数要加@Param

解决:

ideamaven搭建ssH框架步骤 idea 创建maven springboot框架_intellij-idea_30

参考:MyBatis参数注入报错Caused by: org.apache.ibatis.binding.BindingException: Parameter ‘name‘ not found.

10.java.lang.IllegalStateException: Failed to load ApplicationContext

Caused by: while parsing a block mapping in ‘reader’, line 1, column 1: spring:

原因:yml文件格式异常,实体类路径错误

解决:修改yml文件

ideamaven搭建ssH框架步骤 idea 创建maven springboot框架_intellij-idea_31

参考:Spring Boot常见报错1-while parsing a block mapping

11.Error querying database. Cause: java.sql.SQLSyntaxErrorException: Table ‘test.user’ doesn’t exist

原因:表建错了

ideamaven搭建ssH框架步骤 idea 创建maven springboot框架_maven_32

参考:Error querying database. Cause: java.sql.SQLSyntaxErrorException: Table ‘database.record‘ doesn‘t e

12.java.lang.NullPointerException

原因:数据库里没有数据

解决:添加数据

ideamaven搭建ssH框架步骤 idea 创建maven springboot框架_spring_33

13.java.sql.SQLException: The server time zone value ‘�й���׼ʱ��‘ is unrecognized or represents more tha

原因:mysql-connector-java版本导致时区的问题

解决:application.yml的url后加入

&serverTimezone=Asia/Shanghai

参考:[java.sql.SQLException: The server time zone value ‘�й���׼ʱ��‘ is unrecognized or represents more tha

14.java.sql.SQLException: Access denied for user ‘root‘@‘localhost‘ (using password: YES)

原因:密码错误,权限不足

解决:application.yml中password改为正确的

参考:[解决java.sql.SQLException: Access denied for user ‘root‘@‘localhost‘ (using password: YES)