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使用IDEA搭建一个简单的SpringBoot项目超详细过程

一、创建项目

1.File->new->project;

2.选择[Spring Initializr],点击next;(jdk1.8默认即可)

3.完善项目信息,组名可不做修改,项目名可做修改;最终建的项目名为:test,src->main->java下包名会是:com->example->test;点击next;

4.Web下勾选Spring Web Start,(网上创建springboot项目多是勾选Web选项,而较高版本的Springboot没有此选项,勾选Spring Web Start即可,2.1.8版本是Spring Web);Template Englines勾选Thymeleaf;SQL勾选:MySQL Driver,JDBC API 和 MyBatis Framework三项;点击next;

5.选择项目路径,点击finish;打开新的窗口;

6.刚创建好的项目目录结构

7.点击右侧的Maven,点击设置(扳手图标)进行项目Maven仓库的配置;

8.(1)选择本地Maven路径;(2)勾选配置文件后边的选项,然后修改为本地Maven的配置文件,它会根据配置文件直接找到本地仓库位置;

9.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

10.在templates文件下新建index.html页面,作为启动的初始页面;

<!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>

11.在com.example.test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)

package com . example . test . controller ;   import org . springframework . stereotype . Controller ; import org . springframework . web . bind . annotation . RequestMapping ;   @Controller public class HelloController {   @RequestMapping ( "/index" ) public String sayHello (){ return "index" ; } }

12.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:https://blog.csdn.net/qq_29648651/article/details/78503853;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;

spring : datasource : name : test #数据库名 url : jdbc : mysql : //localhost:3306/test #url username : root #用户名 password : 123456 #密码 driver - class - name : com . mysql . jdbc . Driver #数据库链接驱动

13.运行项目启动类TestApplication.java

可以发现上面有一个WARN警告,那是因为还没有配置编写MyBatis的相关文件,下面会进行详解;

2019-08-02 09:14:27.473  WARN 9120 --- [           main] o.m.s.mapper.ClassPathMapperScanner      : No MyBatis mapper was found in '[com.example.test]' package. Please check your configuration.

14.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;

15.在进行下一步编写时,我们先来链接一下数据库;点击右侧的Database,点[加号],新建数据库链接;

16.填写数据库相关信息,点击Test Connection;

17.如果链接失败可能是驱动的问题,点击左上角的小扳手,进入数据库设置界面

18.连接成功后,显示数据库信息,user表的基本信息也显示了,下面就照这个来了;

19.SpringBoot项目大概分为四层:

(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)

(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;

(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)

(4)Web层:就是Controller层,实现与web前端的交互。

依照上面四层,创建目录结构如下:

20.代码展示:

(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 #url username : root #用户名 password : 123456 #密码 driver - class - name : com . mysql . 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.example.test.bean #配置实体类

(2)pom.xml文件配置信息(备注:这个文件以前没有,2019/12/9日粉丝发现的,这个里面也添加了单元测试所需的配置,记得要重新导一下Maven包哦)

<? xml version = "1.0" encoding = "UTF-8" ?> <project xmlns = "http://maven.apache.org/POM/4.0.0" xmlns:xsi = "http://HdhCmsTestw3.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> 2.1.6.RELEASE </version> <relativePath/> <!-- lookup parent from repository --> </parent> <groupId> com.example </groupId> <artifactId> test </artifactId> <version> 0.0.1-SNAPSHOT </version> <name> test </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-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> <!--MyBatis配置--> <dependency> <groupId> org.mybatis.spring.boot </groupId> <artifactId> mybatis-spring-boot-starter </artifactId> <version> 2.1.0 </version> </dependency> <!--MySQL数据库配置--> <dependency> <groupId> mysql </groupId> <artifactId> mysql-connector-java </artifactId> <version> 5.1.41 </version> <scope> runtime </scope> </dependency> <!--单元测试配置--> <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>

(3)Bean实体类,依据数据库表,生成set和get方法;

package com . example . test . 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 . example . test . mapper ;   import com . example . test . bean . UserBean ;   public interface UserMapper {   UserBean getInfo ( String name , 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<mapper>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.example.test.mapper.UserMapper" >   <select id = "getInfo" parameterType = "String" resultType = "com.example.test.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 . example . test . service ;   import com . example . test . 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 . example . test . serviceImpl ;   import com . example . test . bean . UserBean ; import com . example . test . mapper . UserMapper ; import com . example . test . service . UserService ; import org . springframework . beans . factory . annotation . Autowired ; import org . springframework . stereotype . Service ;   @Service public class UserServiceImpl 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 . example . test ;   import org . mybatis . spring . annotation . MapperScan ; import org . springframework . boot . SpringApplication ; import org . springframework . boot . autoconfigure . SpringBootApplication ;   @SpringBootApplication @MapperScan ( "com.example.test.mapper" ) public class TestApplication {   public static void main ( String [] args ) { SpringApplication . run ( TestApplication . 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 . example . test ;   import com . example . test . bean . UserBean ; import com . example . test . service . UserService ; import org . junit . 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 public class TestApplicationTests {   @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 . example . test . controller ;   import com . example . test . bean . UserBean ; import com . example . test . 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>

21.先运行测试类,看是否成功获取数据库信息:

22.同时发现一条警告信息,是数据库连接的jar包问题:

2019-08-02 11:25:04.150  WARN 16868 --- [           main] com.zaxxer.hikari.util.DriverDataSource  : Registered driver with driverClassName=com.mysql.jdbc.Driver was not found, trying direct instantiation.

打开pom.xml文件,发现配置文件中未指定数据库连接的jar包的版本号,用version标签引入

<version>5.1.41</version>

重新运行测试类,WARN警告消除

23.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

项目到这里就算完美结束了。

项目源码放在GitHub上,可以下载参考 :https://github测试数据/redesperado/SpringBoot.git

有一个基于本项目添加增删改查功能的项目,仅供参考 :https://github测试数据/redesperado/test1.git

附一个微服务项目搭建过程,有想学的可以参考一下

IDEA基于springboot采用Dubbo+zookeeper+Redis搭建微服务项目-详细教程:https://blog.csdn.net/baidu_39298625/article/details/108330298

大家如果在创建过程 中遇到什么问题,可以在下边提供的链接中看看,这些是我在创建项目过程遇到的问题,希望可以帮到大家:

1.启动报错:Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.

https://blog.csdn.net/baidu_39298625/article/details/98261102

2.mapper.xml文件数据库字段报红

https://blog.csdn.net/baidu_39298625/article/details/98265845

3.项目正常启动,访问默认index页面时404

https://blog.csdn.net/baidu_39298625/article/details/98501840

4. 链接MySQL数据库报错:java.sql.SQLException: The server time zone value '?й???????' is unrecognized or represents more than one time zone. You must configure either the server or JDBC driver (via the serverTimezone configuration property) to use a more specifc time zone value if you want to utilize time zone support.

https://blog.csdn.net/baidu_39298625/article/details/100915264

5.中文用户名登录失败,无报错信息

https://blog.csdn.net/baidu_39298625/article/details/103494461

到此这篇关于使用IDEA搭建一个简单的SpringBoot项目超详细过程的文章就介绍到这了,更多相关idea搭建springboot项目内容请搜索我们以前的文章或继续浏览下面的相关文章希望大家以后多多支持!

原文链接:https://blog.csdn.net/baidu_39298625/article/details/98102453

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