SpringBoot專案建立步驟
1. 建立SpringBoot工程
(1) File → New → Project → Spring Initilizr
(2) Name：MySpringBoot
(3) Group: com.baidu
(4) java: 8
(5) Next
(6) Finish
(7) This Window
(8) 配置maven環境：
① File → Settings → Build,Execution,Deployment → Build Tools → Maven
② Maven Home Path：Maven檔案路徑
③ User setting files: Maven檔案路徑 → conf → logging → setting檔案
④ Local repository：自建路徑（D:\Java\repository）
⑤ OK
2. 建立Maven工程
(1) MySpringBoot下右鍵 → New → moudle → Maven
(2) Next
(3) Name：springboot_demo4
(4) Groupid :com.baidu
(5) Finish
3. 編輯Spring MVC
目錄結構如下：
操作步驟：
(1) 編輯pom.xml檔案
<?xml version="1.0" encoding="UTF-8"?>
2 <project xmlns="http://maven.apache.org/POM/4.0.0"
3 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
4 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
5 <modelVersion>4.0.0</modelVersion>
6
7 <groupId>com.jt</groupId>
8 <artifactId>springboot_demo3</artifactId>
9 <version>1.0-SNAPSHOT</version>
10
11 <!--1.parent標籤-->
12 <!--集中定義版本號-->
13 <parent>
14 <groupId>org.springframework.boot</groupId>
15 <artifactId>spring-boot-starter-parent</artifactId>
16 <version>2.5.1</version>
17 <relativePath/> <!-- lookup parent from repository -->
18 </parent>
19
20
21 <!--2.新增依賴項-->
22 <!--依賴: 專案中需要新增什麼功能,則依賴什麼jar包.-->
23 <dependencies>
24 <!--引入SpringMVC功能-->
25 <dependency>
26 <groupId>org.springframework.boot</groupId>
27 <artifactId>spring-boot-starter-web</artifactId>
28 </dependency>
29 <!--SpringBoot的測試功能-->
30 <dependency>
31 <groupId>org.springframework.boot</groupId>
32 <artifactId>spring-boot-starter-test</artifactId>
33 <scope>test</scope>
34 </dependency>
35
36 <!--SpringBoot核心機制: "開箱即用"
37 只需匯入特定的jar包檔案 則可以直接使用其中的功能
38 根本原因: SpringBoot是對框架的簡化,內部進行了擴充套件,無需程式設計師操作.
39 -->
40 <!--支援熱部署 -->
41 <dependency>
42 <groupId>org.springframework.boot</groupId>
43 <artifactId>spring-boot-devtools</artifactId>
44 </dependency>
45
46 <!--引入外掛lombok 自動的set/get/構造方法外掛 -->
47 <dependency>
48 <groupId>org.projectlombok</groupId>
49 <artifactId>lombok</artifactId>
50 </dependency>
51
52 <!--引入資料庫驅動 -->
53 <dependency>
54 <groupId>mysql</groupId>
55 <artifactId>mysql-connector-java</artifactId>
56 <scope>runtime</scope>
57 </dependency>
58
59 <!--springBoot資料庫連線 -->
60 <dependency>
61 <groupId>org.springframework.boot</groupId>
62 <artifactId>spring-boot-starter-jdbc</artifactId>
63 </dependency>
64
65 <!--spring整合mybatis-plus MP中包含了mybatis的包所以將原來的包刪除 -->
66 <dependency>
67 <groupId>com.baomidou</groupId>
68 <artifactId>mybatis-plus-boot-starter</artifactId>
69 <version>3.4.3</version>
70 </dependency>
71
72 </dependencies>
73
74
75 <!--3.新增build標籤-->
76 <!--該外掛是SpringBoot專案打包時必須新增的.
77 如果沒有該外掛 則導致jar包不能執行
78 -->
79 <build>
80 <plugins>
81 <plugin>
82 <groupId>org.springframework.boot</groupId>
83 <artifactId>spring-boot-maven-plugin</artifactId>
84 <version>2.5.1</version>
85 </plugin>
86 </plugins>
87 </build>
88 </project>
(2) 編輯主啟動類
① @SpringBootApplication
② @MapperScan(“com.jt.mapper”) --> 包掃描
1 package com.jt;
2
3 import org.mybatis.spring.annotation.MapperScan;
4 import org.springframework.boot.SpringApplication;
5 import org.springframework.boot.autoconfigure.SpringBootApplication;
6
7 @SpringBootApplication
8 @MapperScan("com.jt.mapper")
9 public class RunApp {
10 public static void main(String[] args) {
11 SpringApplication.run(RunApp.class, args);
12 }
13 }
(3) 編輯pojo包下的User類
① @Data --> 自動生成setter/getter/to string/構造方法等
② @Accessors(chain = true) --> 啟動鏈式載入（重寫set方法）
③ @TableName(“demo_user”) --> 使用MP, 類名與表名對映
1 package com.jt.pojo;
2
3 import com.baomidou.mybatisplus.annotation.TableName;
4 import lombok.Data;
5 import lombok.experimental.Accessors;
6
7 import java.io.Serializable;
8
9 @Data
10 @Accessors(chain = true)
11 @TableName("demo_user")
12 //規定：POJO實體一般都需要實現序列號介面
13 public class User implements Serializable {
14 private Integer id;
15 private String name;
16 private Integer age;
17 private String sex;
18 }
(4) 編輯mapper層下的UserMapper介面
1 package com.jt.mapper;
2
3 import com.baomidou.mybatisplus.core.mapper.BaseMapper;
4 import com.jt.pojo.User;
5 import org.apache.ibatis.annotations.Mapper;
6
7 //@Mapper 每個介面都要加一次，麻煩，所以提取到主啟動類RunApp上加@MapperScan("com.jt.Mapper")註解
8 public interface UserMapper extends BaseMapper<User> {
9
10 }
(5) 編輯resources--mappers包下的UserMapper.xml對映檔案
1 <?xml version="1.0" encoding="UTF-8" ?>
2 <!DOCTYPE mapper
3 PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
4 "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
5 <!--語法:namespace="介面的路徑" -->
6 <mapper namespace="com.jt.mapper.UserMapper">
7
8 <!-- <select id="findAll" resultType="User">
9 select * from demo_user
10 </select>
11 -->
12 </mapper>
(6) 編輯resources包下的application.yml核心配置檔案
server:
port: 8090
spring:
datasource:
driver-class-name: com.mysql.cj.jdbc.Driver
url: jdbc:mysql://127.0.0.1:3306/jt?serverTimezone=GMT%2B8&useUnicode=true&characterEncoding=utf8&autoReconnect=true&allowMultiQueries=true
username: root
#如果密碼以數字0開頭,則使用""號包裹 "0123456"
password: root #SpringBoot整合MybatisPlus
mybatis-plus:
#設定別名包
type-aliases-package: com.jt.pojo
#載入對映檔案
mapper-locations: classpath:/mappers/*.xml
#開啟駝峰對映
configuration:
map-underscore-to-camel-case: true
#列印Sql語句
logging:
level:
#指定包路徑,日誌輸出
com.jt.mapper: debug
(7) 編輯service層下的UserService介面
1 package com.jt.service;
2
3 import com.jt.pojo.User;
4
5 import java.util.List;
6
7 public interface UserService {
8 List<User> findAll();
9 }
(8) 編輯Service層下的UserServiceImpl實現類
① @Service
② @AutoWired --> 依賴注入
③ @Override --> 重寫介面方法
1 package com.jt.service;
2
3 import com.jt.mapper.UserMapper;
4 import com.jt.pojo.User;
5 import org.springframework.beans.factory.annotation.Autowired;
6 import org.springframework.stereotype.Service;
7
8 import java.util.List;
9
10 @Service
11 public class UserServiceImpl implements UserService {
12 @Autowired
13 public UserMapper userMapper;
14
15 @Override
16 public List<User> findAll() {
17 return userMapper.selectList(null);
18 }
19 }
(9) 編輯controller層下的UserController類
① @RestController
② @CrossOrigin --> 解決跨域問題
③ AutoWired --> 依賴注入
④ @RequestMapping(“findAll”)
1 package com.jt.controller;
2
3 import com.jt.pojo.User;
4 import com.jt.service.UserService;
5 import org.springframework.beans.factory.annotation.Autowired;
6 import org.springframework.web.bind.annotation.CrossOrigin;
7 import org.springframework.web.bind.annotation.RequestMapping;
8 import org.springframework.web.bind.annotation.RestController;
9
10 import java.util.List;
11
12 @CrossOrigin
13 @RestController
14 public class UserController {
15 @Autowired
16 private UserService userService;
17
18 @RequestMapping("findAll")
19 public List<User> find() {
20 return userService.findAll();
21 }
22 }