SpringBoot連接PostgreSQL+MybatisPlus入門案例(代碼詳解)

更新時(shí)間：2024年07月24日 14:28:37 作者：小天博客

這篇文章主要介紹了SpringBoot連接PostgreSQL+MybatisPlus入門案例,本文通過實(shí)例代碼圖文相結(jié)合給大家介紹的非常詳細(xì),感興趣的朋友跟隨小編一起看看吧

項(xiàng)目結(jié)構(gòu)

一、Java代碼

pom.xml

<?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>
    <groupId>org.example</groupId>
    <artifactId>jdservice</artifactId>
    <version>1.0-SNAPSHOT</version>
    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
            <version>2.0.3.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
            <version>2.0.3.RELEASE</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.postgresql/postgresql -->
        <dependency>
            <groupId>org.postgresql</groupId>
            <artifactId>postgresql</artifactId>
            <version>42.6.0</version>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.12</version>
        </dependency>
        <!--mybatis‐plus的springboot支持-->
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>3.1.0</version>
        </dependency>
    </dependencies>
</project>

controller層

package org.example.jd.controller;
import org.example.jd.pojo.TUser;
import org.example.jd.service.TUserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;
import java.util.List;
@CrossOrigin(origins = "http://localhost:8080")
@RestController
public class UserController {
    @Autowired
    private TUserService tUserService;
    @PostMapping("/api/userLogin")
    public String login(@RequestBody TUser tUser) {
        // 實(shí)際業(yè)務(wù)邏輯處理
        String username = tUser.getUsername();
        String password = tUser.getPassword();
        // 這里可以進(jìn)行用戶名密碼驗(yàn)證等操作
        System.out.println("========Login successful=====");
        System.out.println(username + "," + password);
        return "Login successful"; // 返回登錄成功信息或者其他響應(yīng)
    }
    @GetMapping("/api/getUserList")
    public List<TUser> getUserList() {
        List<TUser> tUserList = tUserService.getUserList();
        return tUserList;
    }
}

mapper層

package org.example.jd.mapper;
import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import org.example.jd.pojo.TUser;
public interface TUserMapper extends BaseMapper<TUser> { //參數(shù)為實(shí)體類
}

pojo層

package org.example.jd.pojo;
import com.baomidou.mybatisplus.annotation.TableId;
import com.baomidou.mybatisplus.annotation.TableName;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
import java.time.LocalDate;
@Data
@AllArgsConstructor
@NoArgsConstructor
@TableName("tuser")   //指定數(shù)據(jù)庫表
public class TUser {
    @TableId(value = "uid") //指定主鍵
    private int uid;
    private String username;
    private String password;
    private int age;
    private String gender;
    private LocalDate birthday;
    private String address;
}

service層

TUserService

package org.example.jd.service;
import org.example.jd.pojo.TUser;
import java.util.List;
public interface TUserService {
    List<TUser> getUserList();
}

TUserServiceImp

package org.example.jd.service;
import org.example.jd.mapper.TUserMapper;
import org.example.jd.pojo.TUser;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import java.util.List;
@Service
public class TUserServiceImp implements TUserService {
    @Autowired
    private TUserMapper tUserMapper;
    @Override
    public List<TUser> getUserList() {
        return tUserMapper.selectList(null);
    }
}

Application啟動(dòng)類

package org.example.jd;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
@MapperScan("org.example.jd.mapper") //掃描mapper層
public class Application {
    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }
}

TUserMapper.xml

<?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">
<!--namespace是mapper層對應(yīng)的接口名-->
<mapper namespace="org.example.jd.mapper.TUserMapper">
    <!--id是mapper層對應(yīng)的接口名中對應(yīng)的方法名-->
<!--    <select id="myFindUserById" resultType="User">-->
<!--        select *-->
<!--        from tb_user-->
<!--        where id = #{id}-->
<!--    </select>-->
</mapper>

mybatis-config.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN" "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
    <!--設(shè)置駝峰匹配，MybatisPlus默認(rèn)開啟駝峰匹配-->
    <!--    <settings>-->
    <!--        <setting name="mapUnderscoreToCamelCase" value="true"/>-->
    <!--    </settings>-->
</configuration>

application.yml配置文件

server:
  port: 8090
spring:
  datasource:
    url: jdbc:postgresql://localhost:5432/myjd
    username: postgres
    password: 123456
    driver-class-name: org.postgresql.Driver
#設(shè)置mybatis-plus
mybatis-plus:
  config-location: classpath:mybatis/mybatis-config.xml  #配置文件
  mapper-locations: classpath:mybatis/mapper/*.xml  #設(shè)置mapper層對應(yīng)的接口對應(yīng)的mapper.xml的路徑
  type-aliases-package: org.example.jd.pojo  #設(shè)置別名，mapper.xml中resultType="org.example.jd.pojo.TUser"可省去包，即resultType="TUser"
  #開啟自動(dòng)駝峰映射，注意：配置configuration.map-underscore-to-camel-case則不能配置config-location，可寫到mybatis-config.xml中
#  configuration:
#    map-underscore-to-camel-case: true

二、SQL

/*
 Navicat Premium Data Transfer
 Source Server         : myPgSQL
 Source Server Type    : PostgreSQL
 Source Server Version : 160003 (160003)
 Source Host           : localhost:5432
 Source Catalog        : myjd
 Source Schema         : public
 Target Server Type    : PostgreSQL
 Target Server Version : 160003 (160003)
 File Encoding         : 65001
 Date: 19/07/2024 22:15:18
*/
-- ----------------------------
-- Table structure for tuser
-- ----------------------------
DROP TABLE IF EXISTS "public"."tuser";
CREATE TABLE "public"."tuser" (
  "uid" int4 NOT NULL,
  "username" varchar(255) COLLATE "pg_catalog"."default",
  "age" int4,
  "gender" varchar(1) COLLATE "pg_catalog"."default",
  "birthday" date,
  "address" varchar(255) COLLATE "pg_catalog"."default",
  "password" varchar(255) COLLATE "pg_catalog"."default"
)
;
-- ----------------------------
-- Records of tuser
-- ----------------------------
INSERT INTO "public"."tuser" VALUES (1, 'jack', 24, '男', '2021-10-19', '深圳', '123');
-- ----------------------------
-- Primary Key structure for table tuser
-- ----------------------------
ALTER TABLE "public"."tuser" ADD CONSTRAINT "user_pkey" PRIMARY KEY ("uid");