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!