使用IDEA搭建一個簡單的SpringBoot項目超詳細過程
一、創建項目
1.File->new->project;
2.選擇“Spring Initializr”,點擊next;(jdk1.8默認即可)
3.完善項目信息,組名可不做修改,項目名可做修改;最終建的項目名為:test,src->main->java下包名會是:com->example->test;點擊next;
4.Web下勾選Spring Web Start,(網上創建springboot項目多是勾選Web選項,而較高版本的Springboot沒有此選項,勾選Spring Web Start即可,2.1.8版本是Spring Web);Template Englines勾選Thymeleaf;SQL勾選:MySQL Driver,JDBC API 和 MyBatis Framework三項;點擊next;
5.選擇項目路徑,點擊finish;打開新的窗口;
6.剛創建好的項目目錄結構
7.點擊右側的Maven,點擊設置(扳手圖標)進行項目Maven倉庫的配置;
8.(1)選擇本地Maven路徑;(2)勾選配置文件後邊的選項,然後修改為本地Maven的配置文件,它會根據配置文件直接找到本地倉庫位置;
9.配置完後,如果沒有自動導包,可以點擊左上角重新導包按鈕,或者呢個下載按鈕,選擇下載所有源文件和文檔
10.在templates文件下新建index.html頁面,作為啟動的初始頁面;
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>hello</title> </head> <body> 你好!初學者,我是SpringBoot的簡單啟動頁面! </body> </html>
11.在com.example.test下新建controller文件夾,在controller文件夾下建一個簡單的helloController類;(Controller類要添加@Controller註解,項目啟動時,SpringBoot會自動掃描加載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文件夾下application中先配置DataSource基本信息,application文件有兩種文件格式,一種是以.properties為後綴,一種是以.yml為後綴的,兩種配置方式略有差別,詳情可參考這個網址:https://blog.csdn.net/qq_29648651/article/details/78503853;在這我是用.yml後綴的文件格式。右鍵application文件選擇Refact,選擇Rename,將後綴改為yml;
spring: datasource: name: test #數據庫名 url: jdbc:mysql://localhost:3306/test #url username: root #用戶名 password: 123456 #密碼 driver-class-name: com.mysql.jdbc.Driver #數據庫鏈接驅動
13.運行項目啟動類TestApplication.java
可以發現上面有一個WARN警告,那是因為還沒有配置編寫MyBatis的相關文件,下面會進行詳解;
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.在瀏覽器中輸入localhost:8080,回車顯示初始的index界面;到這項目的初步搭建已經完成,下面可以下一些簡單的業務邏輯,比如從數據庫獲取信息,登錄之類的簡單功能;
15.在進行下一步編寫時,我們先來鏈接一下數據庫;點擊右側的Database,點“加號”,新建數據庫鏈接;
16.填寫數據庫相關信息,點擊Test Connection;
17.如果鏈接失敗可能是驅動的問題,點擊左上角的小扳手,進入數據庫設置界面
18.連接成功後,顯示數據庫信息,user表的基本信息也顯示瞭,下面就照這個來瞭;
19.SpringBoot項目大概分為四層:
(1)DAO層:包括XxxMapper.java(數據庫訪問接口類),XxxMapper.xml(數據庫鏈接實現);(這個命名,有人喜歡用Dao命名,有人喜歡用Mapper,看個人習慣瞭吧)
(2)Bean層:也叫model層,模型層,entity層,實體層,就是數據庫表的映射實體類,存放POJO對象;
(3)Service層:也叫服務層,業務層,包括XxxService.java(業務接口類),XxxServiceImpl.java(業務實現類);(可以在service文件夾下新建impl文件放業務實現類,也可以把業務實現類單獨放一個文件夾下,更清晰)
(4)Web層:就是Controller層,實現與web前端的交互。
依照上面四層,創建目錄結構如下:
20.代碼展示:
(1)在application配置文件中添加MyBatis配置:
spring: datasource: name: test #數據庫名 url: jdbc:mysql://localhost:3306/test #url username: root #用戶名 password: 123456 #密碼 driver-class-name: com.mysql.jdbc.Driver #數據庫鏈接驅動 mybatis: mapper-locations: classpath:mapper/*.xml #配置映射文件 type-aliases-package: com.example.test.bean #配置實體類
(2)pom.xml文件配置信息(備註:這個文件以前沒有,2019/12/9日粉絲發現的,這個裡面也添加瞭單元測試所需的配置,記得要重新導一下Maven包哦)
<?xml version="1.0" encoding="UTF-8"?> <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://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>4.0.0</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依賴--> <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數據庫配置--> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>5.1.41</version> <scope>runtime</scope> </dependency> <!--單元測試配置--> <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實體類,依據數據庫表,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層訪問數據庫接口文件:
package com.example.test.mapper; import com.example.test.bean.UserBean; public interface UserMapper { UserBean getInfo(String name,String password); }
(5)DAO層訪問數據庫實現文件(需在resource包下創建mapper文件夾,然後再創建一個UserMapper.xml.在application配置文件中mybatis:mapper-locations:對應的就是該文件地址),註意<mapper>標簽的namespace屬性要填寫 訪問數據庫接口類文件路徑:
<?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層業務接口類編寫:
package com.example.test.service; import com.example.test.bean.UserBean; public interface UserService { UserBean loginIn(String name,String password); }
(7)Service層業務實現類編寫,註意要註解@Service,註入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 { //將DAO註入Service層 @Autowired private UserMapper userMapper; @Override public UserBean loginIn(String name, String password) { return userMapper.getInfo(name,password); } }
(8)項目啟動類要添加註解@MapperScan項目啟動時掃描mapper接口,否則會報錯找不到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)編寫測試類,看是否能成功 訪問數據庫,獲取數據庫信息:
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("該用戶ID為:"); System.out.println(userBean.getId()); } }
(10) controller層,註意添加@controller註解,註入Service服務:
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 { //將Service註入Web層 @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"> 賬號:<input type="text" id="name" name = "name"> <br> 密碼:<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>登錄成功!</h1> </body> </html>
error.html
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>error</title> </head> <body> <h1>登錄失敗!</h1> </body> </html>
21.先運行測試類,看是否成功獲取數據庫信息:
22.同時發現一條警告信息,是數據庫連接的jar包問題:
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.
打開pom.xml文件,發現配置文件中未指定數據庫連接的jar包的版本號,用version標簽引入
<version>5.1.41</version>
重新運行測試類,WARN警告消除
23.運行TestApplication.java文件,啟動項目,無任何WARN警告信息,進入瀏覽器輸入localhost:8080/login
項目到這裡就算完美結束瞭。
項目源碼放在GitHub上,可以下載參考:https://github.com/redesperado/SpringBoot.git
有一個基於本項目添加增刪改查功能的項目,僅供參考:https://github.com/redesperado/test1.git
附一個微服務項目搭建過程,有想學的可以參考一下
IDEA基於springboot采用Dubbo+zookeeper+Redis搭建微服務項目-詳細教程:https://blog.csdn.net/baidu_39298625/article/details/108330298
大傢如果在創建過程 中遇到什麼問題,可以在下邊提供的鏈接中看看,這些是我在創建項目過程遇到的問題,希望可以幫到大傢:
1.啟動報錯: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文件數據庫字段報紅
https://blog.csdn.net/baidu_39298625/article/details/98265845
3.項目正常啟動,訪問默認index頁面時404
https://blog.csdn.net/baidu_39298625/article/details/98501840
4. 鏈接MySQL數據庫報錯:java.sql.SQLException: The server time zone value ‘�й���ʱ��’ 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.中文用戶名登錄失敗,無報錯信息
https://blog.csdn.net/baidu_39298625/article/details/103494461
到此這篇關於使用IDEA搭建一個簡單的SpringBoot項目超詳細過程的文章就介紹到這瞭,更多相關idea搭建springboot項目內容請搜索WalkonNet以前的文章或繼續瀏覽下面的相關文章希望大傢以後多多支持WalkonNet!
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