idea+gradle+springboot+mybatis+mysql+navicat

1、目录结构

2、实体类

(1) Books.java

package com.hello.demo.Untiy;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
@Data
@AllArgsConstructor
@NoArgsConstructor
public class Books {
    private int bookId;
    private String bookName;
    private int bookCounts;
    private String detail;
}

3、Dao层

（1）HelloController.java

package com.hello.demo.Mapper;

import com.hello.demo.Untiy.Books;
import org.apache.ibatis.annotations.Mapper;

import java.util.List;
@Mapper
public interface BooksMapper {
    //增加一个Book
    int addBook(Books book);

    //根据id删除一个Book
    int deleteBookById(int id);

    //更新Book
    int updateBook(Books books);

    //根据id查询,返回一个Book
    Books queryBookById(int id);

    //查询全部Book,返回list集合
    List<Books> queryAllBook();
}

（2）BooksMapper.xml

DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">

<mapper namespace="com.hello.demo.Mapper.BooksMapper">

    
    <insert id="addBook" parameterType="com.hello.demo.Untiy.Books">
        insert into books(book_id,book_name,book_counts,detail)
        values (#{bookId},#{bookName}, #{bookCounts}, #{detail})
    insert>

    
    <delete id="deleteBookById" parameterType="int">
        delete from books where book_id=#{bookId}
    delete>

    
    <update id="updateBook" parameterType="com.hello.demo.Untiy.Books">
        update books
        set book_name = #{bookName},book_counts = #{bookCounts},detail = #{detail}
        where book_id = #{bookId}
    update>

    
    <select id="queryBookById" resultType="com.hello.demo.Untiy.Books">
        select * from books
        where book_id = #{bookId}
    select>

    
    <select id="queryAllBook" resultType="com.hello.demo.Untiy.Books">
        select * from books order by book_id
    select>

mapper>

4、Service层

(1) 接口：BookService.java

package com.hello.demo.Service;

import com.hello.demo.Untiy.Books;

import java.util.List;

public interface BookService {
    //增加一个Book
    int addBook(Books book);
    //根据id删除一个Book
    int deleteBookById(int id);
    //更新Book
    int updateBook(Books books);
    //根据id查询,返回一个Book
    Books queryBookById(int id);
    //查询全部Book,返回list集合
    List<Books> queryAllBook();
}

（2）接口实现类：BookServiceImpl.java

package com.hello.demo.Service.ServiceImpl;

import com.hello.demo.Mapper.BooksMapper;
import com.hello.demo.Service.BookService;
import com.hello.demo.Untiy.Books;
import lombok.RequiredArgsConstructor;
import org.springframework.stereotype.Service;

import java.util.List;

@Service
@RequiredArgsConstructor
public class BookServiceImpl  implements BookService {
    //调用dao层的操作，设置一个set接口，方便Spring管理
    private final BooksMapper bookMapper;

    public int addBook(Books book) {
        return bookMapper.addBook(book);
    }

    public int deleteBookById(int id) {
        return bookMapper.deleteBookById(id);
    }

    public int updateBook(Books books) {
        return bookMapper.updateBook(books);
    }

    public Books queryBookById(int id) {
        return bookMapper.queryBookById(id);
    }

    public List<Books> queryAllBook() {
        return bookMapper.queryAllBook();
    }

}

5、Controller层

(1) HelloController.java

package com.hello.demo.Controller;

import com.hello.demo.Service.BookService;
import com.hello.demo.Untiy.Books;
import lombok.RequiredArgsConstructor;
import org.springframework.web.bind.annotation.*;

import java.util.List;

@RestController
@RequiredArgsConstructor
public class HelloController {

    private final BookService bookService;

//    @GetMapping("/hello")
//    public String book() {
//        return bookService.list();
//    }

    //查询全部Book,返回list集合
    @GetMapping("/queryallbook")
    public List<Books> queryAllBook() {
        return bookService.queryAllBook();
    }

    //根据id查詢一个Book
    @GetMapping("/queryonebook/{bookId}")
    public Books queryOneBook(@PathVariable("bookId") int id) {
        Books book = bookService.queryBookById(id);
        return book;
    }

    //根据id删除一个Book
    @DeleteMapping("/deletebook/{bookId}")
    public int deleteBook(@PathVariable("bookId") int id) {
        return bookService.deleteBookById(id);
    }

    //根据id更新一个Book
    @PostMapping("/updateonebook")
    public int updateBook(@RequestBody Books books){
        return bookService.updateBook(books);
    }

    //新增一个Book
    @PutMapping("/addonebook")
    public int addBook(@RequestBody Books books){
        return bookService.addBook(books);
    }
}

6、build.gradle

plugins {
    id 'org.springframework.boot' version '2.5.2'
    id 'io.spring.dependency-management' version '1.0.11.RELEASE'
    id 'java'
    id 'war'
}
ext {
    mybatisplusVersion = '3.4.2'
    swaggerFoxVersion = '2.9.2'
    swaggerCoreVersion = '1.5.24'
    postGisJdbcVersion = '2.5.0'
    druidVersion = '1.1.9'
    hutoolVersion = '5.3.8'
    aspectVersion = '1.8.10'
    easyExcelVersion = '2.2.6'
}
group = 'com.Hello'
version = '0.0.1-SNAPSHOT'
sourceCompatibility = '1.8'

configurations {
    compileOnly {
        extendsFrom annotationProcessor
    }
}

repositories {
    mavenCentral()
}

dependencies {


    implementation 'org.springframework.boot:spring-boot-starter-web'
    implementation 'org.mybatis.spring.boot:mybatis-spring-boot-starter:2.2.0'
    compileOnly 'org.projectlombok:lombok'
    annotationProcessor 'org.projectlombok:lombok'

    /* MyBatis-Plus */
    implementation("com.baomidou:mybatis-plus-boot-starter:${mybatisplusVersion}")
    /* Druid 连接池 */
    implementation("com.alibaba:druid-spring-boot-starter:${druidVersion}")

    /* PostgreSQL */
    implementation 'org.postgresql:postgresql:9.4.1212.jre7'

    /* PostGis-Jdbc */
    implementation("net.postgis:postgis-jdbc:${postGisJdbcVersion}")

    compile 'com.alibaba:druid:1.0.27'
    compile group: 'org.springframework.boot', name: 'spring-boot-starter-log4j2', version: '1.4.0.RELEASE'
    implementation 'junit:junit:4.12'
// 排除冲突
    configurations {
        mybatisGenerator
        compile.exclude module: 'spring-boot-starter-logging'
    }
}

test {
    useJUnitPlatform()
}

7、application.yml

server:
  port: 8080

spring:
  datasource:
    driver-class-name: org.postgis.DriverWrapper
    url: jdbc:postgresql_postGIS://***/BOOK?useUnicode=true&characterEncoding=UTF-8
    username: postgres
    password: 123456
    # ??druid???
    type: com.alibaba.druid.pool.DruidDataSource
    filters: stat
    maxActive: 20
    initialSize: 1
    maxWait: 60000
    minIdle: 1
    timeBetweenEvictionRunsMillis: 60000
    minEvictableIdleTimeMillis: 300000
    validationQuery: select 'x'
    testWhileIdle: true
    testOnBorrow: false
    testOnReturn: false
    poolPreparedStatements: true
    maxOpenPreparedStatements: 20

# MyBatis-Plus Config
mybatis-plus:
  mapper-locations: classpath:/Mapper/*Mapper.xml
  global-config:
    banner: false
    db-config:
      id-type: auto
      table-underline: true
      logic-delete-value: 1
      logic-not-delete-value: 0
  configuration:
    map-underscore-to-camel-case: true
    log-impl: org.apache.ibatis.logging.stdout.StdOutImpl

8、数据库结构