SpringBoot项目创建流程--SpringMVC

SpringBoot项目创建步骤

1. 创建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环境：

① File → Settings → Build,Execution,Deployment → Build Tools → Maven

② Maven Home Path：Maven文件路径

③ User setting files:  Maven文件路径 → conf → logging → setting文件

④ Local repository：自建路径（D:\Java\repository）

⑤ OK

2. 创建Maven工程

(1) MySpringBoot下右键 → New → moudle → Maven

(2) Next

(3) Name：springboot_demo4

(4) Groupid :com.baidu

(5) Finish

3. 编辑Spring MVC

目录结构如下：

操作步骤：

(1) 编辑pom.xml文件

 <?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标签-->
12     <!--集中定义版本号-->
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.添加依赖项-->
22     <!--依赖: 项目中需要添加什么功能,则依赖什么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的测试功能-->
30         <dependency>
31             <groupId>org.springframework.boot</groupId>
32             <artifactId>spring-boot-starter-test</artifactId>
33             <scope>test</scope>
34         </dependency>
35
36         <!--SpringBoot核心机制: "开箱即用"
37         只需导入特定的jar包文件 则可以直接使用其中的功能
38         根本原因: SpringBoot是对框架的简化,内部进行了扩展,无需程序员操作.
39         -->
40         <!--支持热部署 -->
41         <dependency>
42             <groupId>org.springframework.boot</groupId>
43             <artifactId>spring-boot-devtools</artifactId>
44         </dependency>
45
46         <!--引入插件lombok 自动的set/get/构造方法插件  -->
47         <dependency>
48             <groupId>org.projectlombok</groupId>
49             <artifactId>lombok</artifactId>
50         </dependency>
51
52         <!--引入数据库驱动 -->
53         <dependency>
54             <groupId>mysql</groupId>
55             <artifactId>mysql-connector-java</artifactId>
56             <scope>runtime</scope>
57         </dependency>
58
59         <!--springBoot数据库连接  -->
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的包所以将原来的包删除 -->
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.添加build标签-->
76     <!--该插件是SpringBoot项目打包时必须添加的.
77        如果没有该插件 则导致jar包不能运行
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) 编辑主启动类

　　① @SpringBootApplication

　　② @MapperScan(“com.jt.mapper”)  --> 包扫描

 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) 编辑pojo包下的User类

　　① @Data  --> 自动生成setter/getter/to string/构造方法等

　　② @Accessors(chain = true)   --> 启动链式加载（重写set方法）

　　③ @TableName(“demo_user”)  --> 使用MP, 类名与表名映射

 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                   //规定：POJO实体一般都需要实现序列号接口
13 public class User implements Serializable {
14     private Integer id;
15     private String name;
16     private Integer age;
17     private String sex;
18 }

(4) 编辑mapper层下的UserMapper接口

 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 每个接口都要加一次，麻烦，所以提取到主启动类RunApp上加@MapperScan("com.jt.Mapper")注解
 8 public interface UserMapper extends BaseMapper<User> {
 9
10 }

(5) 编辑resources--mappers包下的UserMapper.xml映射文件

 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 <!--语法:namespace="接口的路径" -->
 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) 编辑resources包下的application.yml核心配置文件

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
    #如果密码以数字0开头,则使用""号包裹  "0123456"
    password: root

#SpringBoot整合MybatisPlus
mybatis-plus:
  #设置别名包
  type-aliases-package: com.jt.pojo
  #加载映射文件
  mapper-locations: classpath:/mappers/*.xml
  #开启驼峰映射
  configuration:
    map-underscore-to-camel-case: true
#打印Sql语句
logging:
  level:
    #指定包路径,日志输出
    com.jt.mapper: debug

(7) 编辑service层下的UserService接口

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) 编辑Service层下的UserServiceImpl实现类

　　① @Service

　　② @AutoWired  --> 依赖注入

　　③ @Override  --> 重写接口方法

 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) 编辑controller层下的UserController类

　　① @RestController

　　② @CrossOrigin  --> 解决跨域问题

　　③ AutoWired  --> 依赖注入

　　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 }