SpringBoot连接PostgreSQL+MybatisPlus入门案例

项目结构

一、Java代码

pom.xml

1. <?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>
7.     <groupId>org.example</groupId>
8.     <artifactId>jdservice</artifactId>
9.     <version>1.0-SNAPSHOT</version>
11.     <properties>
12.         <maven.compiler.source>8</maven.compiler.source>
13.         <maven.compiler.target>8</maven.compiler.target>
14.         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
15.     </properties>
16.     <dependencies>
17.         <dependency>
18.             <groupId>org.springframework.boot</groupId>
19.             <artifactId>spring-boot-starter-web</artifactId>
20.             <version>2.0.3.RELEASE</version>
21.         </dependency>
22.         <dependency>
23.             <groupId>org.springframework.boot</groupId>
24.             <artifactId>spring-boot-starter</artifactId>
25.             <version>2.0.3.RELEASE</version>
26.         </dependency>
27.         <!-- https://mvnrepository.com/artifact/org.postgresql/postgresql -->
28.         <dependency>
29.             <groupId>org.postgresql</groupId>
30.             <artifactId>postgresql</artifactId>
31.             <version>42.6.0</version>
32.         </dependency>
33.         <dependency>
34.             <groupId>org.projectlombok</groupId>
35.             <artifactId>lombok</artifactId>
36.             <version>1.18.12</version>
37.         </dependency>
38.         <!--mybatis‐plus的springboot支持-->
39.         <dependency>
40.             <groupId>com.baomidou</groupId>
41.             <artifactId>mybatis-plus-boot-starter</artifactId>
42.             <version>3.1.0</version>
43.         </dependency>
46.     </dependencies>
47. </project>

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controller层

1. package org.example.jd.controller;
3. import org.example.jd.pojo.TUser;
4. import org.example.jd.service.TUserService;
5. import org.springframework.beans.factory.annotation.Autowired;
6. import org.springframework.web.bind.annotation.*;
8. import java.util.List;
10. @CrossOrigin(origins = "http://localhost:8080")
11. @RestController
12. public class UserController {
14.     @Autowired
15.     private TUserService tUserService;
17.     @PostMapping("/api/userLogin")
18.     public String login(@RequestBody TUser tUser) {
19.         // 实际业务逻辑处理
20.         String username = tUser.getUsername();
21.         String password = tUser.getPassword();
23.         // 这里可以进行用户名密码验证等操作
24.         System.out.println("========Login successful=====");
25.         System.out.println(username + "," + password);
26.         return "Login successful"; // 返回登录成功信息或者其他响应
27.     }
29.     @GetMapping("/api/getUserList")
30.     public List<TUser> getUserList() {
31.         List<TUser> tUserList = tUserService.getUserList();
32.         return tUserList;
33.     }
36. }

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mapper层

1. package org.example.jd.mapper;
3. import com.baomidou.mybatisplus.core.mapper.BaseMapper;
4. import org.example.jd.pojo.TUser;
6. public interface TUserMapper extends BaseMapper<TUser> { //参数为实体类
8. }

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pojo层

1. package org.example.jd.pojo;
3. import com.baomidou.mybatisplus.annotation.TableId;
4. import com.baomidou.mybatisplus.annotation.TableName;
5. import lombok.AllArgsConstructor;
6. import lombok.Data;
7. import lombok.NoArgsConstructor;
9. import java.time.LocalDate;
11. @Data
12. @AllArgsConstructor
13. @NoArgsConstructor
14. @TableName("tuser")   //指定数据库表
15. public class TUser {
16.     @TableId(value = "uid") //指定主键
17.     private int uid;
18.     private String username;
19.     private String password;
20.     private int age;
21.     private String gender;
22.     private LocalDate birthday;
23.     private String address;
24. }

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service层

TUserService 

1. package org.example.jd.service;
3. import org.example.jd.pojo.TUser;
5. import java.util.List;
7. public interface TUserService {
8.     List<TUser> getUserList();
9. }

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TUserServiceImp 

1. package org.example.jd.service;
3. import org.example.jd.mapper.TUserMapper;
4. import org.example.jd.pojo.TUser;
5. import org.springframework.beans.factory.annotation.Autowired;
6. import org.springframework.stereotype.Service;
8. import java.util.List;
10. @Service
11. public class TUserServiceImp implements TUserService {
13.     @Autowired
14.     private TUserMapper tUserMapper;
15.     @Override
16.     public List<TUser> getUserList() {
17.         return tUserMapper.selectList(null);
18.     }
19. }

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Application启动类

1. package org.example.jd;
3. import org.mybatis.spring.annotation.MapperScan;
4. import org.springframework.boot.SpringApplication;
5. import org.springframework.boot.autoconfigure.SpringBootApplication;
7. @SpringBootApplication
8. @MapperScan("org.example.jd.mapper") //扫描mapper层
9. public class Application {
10.     public static void main(String[] args) {
11.         SpringApplication.run(Application.class, args);
12.     }
13. }

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TUserMapper.xml

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">
6. <!--namespace是mapper层对应的接口名-->
7. <mapper namespace="org.example.jd.mapper.TUserMapper">
9.     <!--id是mapper层对应的接口名中对应的方法名-->
10. <!--    <select id="myFindUserById" resultType="User">-->
11. <!--        select *-->
12. <!--        from tb_user-->
13. <!--        where id = #{id}-->
14. <!--    </select>-->
15. </mapper>

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mybatis-config.xml

1. <?xml version="1.0" encoding="UTF-8" ?>
2. <!DOCTYPE configuration
3.         PUBLIC "-//mybatis.org//DTD Config 3.0//EN" "http://mybatis.org/dtd/mybatis-3-config.dtd">
4. <configuration>
5.     <!--设置驼峰匹配，MybatisPlus默认开启驼峰匹配-->
6.     <!--    <settings>-->
7.     <!--        <setting name="mapUnderscoreToCamelCase" value="true"/>-->
8.     <!--    </settings>-->
10. </configuration>

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application.yml配置文件

1. server:
2.   port: 8090
3. spring:
4.   datasource:
5.     url: jdbc:postgresql://localhost:5432/myjd
6.     username: postgres
7.     password: 123456
8.     driver-class-name: org.postgresql.Driver
11. #设置mybatis-plus
12. mybatis-plus:
13.   config-location: classpath:mybatis/mybatis-config.xml  #配置文件
14.   mapper-locations: classpath:mybatis/mapper/*.xml  #设置mapper层对应的接口对应的mapper.xml的路径
15.   type-aliases-package: org.example.jd.pojo  #设置别名，mapper.xml中resultType="org.example.jd.pojo.TUser"可省去包，即resultType="TUser"
16.   #开启自动驼峰映射，注意：配置configuration.map-underscore-to-camel-case则不能配置config-location，可写到mybatis-config.xml中
17. #  configuration:
18. #    map-underscore-to-camel-case: true

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二、SQL

1. /*
2. Navicat Premium Data Transfer
4. Source Server         : myPgSQL
5. Source Server Type    : PostgreSQL
6. Source Server Version : 160003 (160003)
7. Source Host           : localhost:5432
8. Source Catalog        : myjd
9. Source Schema         : public
11. Target Server Type    : PostgreSQL
12. Target Server Version : 160003 (160003)
13. File Encoding         : 65001
15. Date: 19/07/2024 22:15:18
16. */
19. -- ----------------------------
20. -- Table structure for tuser
21. -- ----------------------------
22. DROP TABLE IF EXISTS "public"."tuser";
23. CREATE TABLE "public"."tuser" (
24.   "uid" int4 NOT NULL,
25.   "username" varchar(255) COLLATE "pg_catalog"."default",
26.   "age" int4,
27.   "gender" varchar(1) COLLATE "pg_catalog"."default",
28.   "birthday" date,
29.   "address" varchar(255) COLLATE "pg_catalog"."default",
30.   "password" varchar(255) COLLATE "pg_catalog"."default"
31. )
32. ;
34. -- ----------------------------
35. -- Records of tuser
36. -- ----------------------------
37. INSERT INTO "public"."tuser" VALUES (1, 'jack', 24, '男', '2021-10-19', '深圳', '123');
39. -- ----------------------------
40. -- Primary Key structure for table tuser
41. -- ----------------------------
42. ALTER TABLE "public"."tuser" ADD CONSTRAINT "user_pkey" PRIMARY KEY ("uid");

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三、运行

欣赏器或者postman请求地址。
注意：欣赏器只能测试get请求，假如有put、post、delete请使用postman测试。

1. http://localhost:8090/api/getUserList

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