<?@H_285_197@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/XMLscheR_623_11845@a-instance"
 4          xsi:scheR_623_11845@aLOCATIOn="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
 5     <@H_567_205@modelVersion>4.0.0</@H_567_205@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>@H_204_3@mysql</groupId>
55             <artifactId>@H_204_3@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>@H_204_3@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>

 @H_772_27@

 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 }

 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 }

 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 }

 1 <?@H_285_197@xml version="1.0" encoding="UTF-8" ?>
 2 <!@H_285_197@DOCTYPE mapper
 3 @H_285_197@        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
 4 @H_285_197@        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
 5 <!--语法:namespace="接口的路径" -->
 6 <@H_567_205@mapper namespace="com.jt.mapper.UserMapper">
 7 
 8  <!--   <SELEct id="findAll" resultType="User">
 9         SELEct * from demo_user
10     </SELEct>
11 -->
12 </@H_567_205@mapper>

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

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 }

 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 }

 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 }