《SpringBoot+MyBatis-Plus 实战：从零搭建简易图书管理系统

一、项目创建 & 依赖引入

IDEA 创建 SpringBoot 项目，pom.xml 完整依赖

<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.7.15</version>
        <relativePath/>
    </parent>
    <groupId>com.book</groupId>
    <artifactId>book-manager</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>book-manager</name>
    <description>图书管理系统</description>

    <properties>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <!--web-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <!--mybatis-plus-->
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>3.5.3.1</version>
        </dependency>
        <!--mysql驱动-->
        <dependency>
            <groupId>com.mysql</groupId>
            <artifactId>mysql-connector-j</artifactId>
            <scope>runtime</scope>
        </dependency>
        <!--lombok-->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <!--测试-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <configuration>
                    <excludes>
                        <exclude>
                            <groupId>org.projectlombok</groupId>
                            <artifactId>lombok</artifactId>
                        </exclude>
                    </excludes>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

二、数据库设计

MySQL 建表语句

CREATE DATABASE IF NOT EXISTS book_db DEFAULT CHARACTER SET utf8mb4;
USE book_db;

CREATE TABLE book (
    id INT PRIMARY KEY AUTO_INCREMENT COMMENT '主键',
    book_name VARCHAR(100) NOT NULL COMMENT '图书名称',
    author VARCHAR(50) NOT NULL COMMENT '作者',
    price DECIMAL(10,2) COMMENT '价格',
    create_time DATETIME DEFAULT CURRENT_TIMESTAMP COMMENT '创建时间'
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

三、配置文件 application.yml

server:
  port: 8080
spring:
  datasource:
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://localhost:3306/book_db?useUnicode=true&characterEncoding=utf8&serverTimezone=Asia/Shanghai
    username: root
    password: 你的mysql密码
mybatis-plus:
  configuration:
    map-underscore-to-camel-case: true
    log-impl: org.apache.ibatis.logging.stdout.StdOutImpl
  global-config:
    db-config:
      id-type: auto

四、代码分层结构

com.book
├── BookManagerApplication.java 启动类
├── entity
│   └── Book.java 实体类
├── mapper
│   └── BookMapper.java
├── service
│   ├── BookService.java
│   └── impl
│       └── BookServiceImpl.java
└── controller
    └── BookController.java

1. 启动类 BookManagerApplication.java

package com.book;

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
@MapperScan("com.book.mapper")
public class BookManagerApplication {
    public static void main(String[] args) {
        SpringApplication.run(BookManagerApplication.class, args);
    }
}

2. 实体类 Book.java

package com.book.entity;

import com.baomidou.mybatisplus.annotation.IdType;
import com.baomidou.mybatisplus.annotation.TableId;
import com.baomidou.mybatisplus.annotation.TableName;
import lombok.Data;

import java.math.BigDecimal;
import java.util.Date;

@Data
@TableName("book")
public class Book {
    @TableId(type = IdType.AUTO)
    private Integer id;
    private String bookName;
    private String author;
    private BigDecimal price;
    private Date createTime;
}

3. Mapper 接口 BookMapper.java

package com.book.mapper;

import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.book.entity.Book;
import org.apache.ibatis.annotations.Mapper;

@Mapper
public interface BookMapper extends BaseMapper<Book> {
}

4. Service 层

BookService.java

package com.book.service;

import com.baomidou.mybatisplus.extension.service.IService;
import com.book.entity.Book;

public interface BookService extends IService<Book> {
}

BookServiceImpl.java

package com.book.service.impl;

import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.book.entity.Book;
import com.book.mapper.BookMapper;
import com.book.service.BookService;
import org.springframework.stereotype.Service;

@Service
public class BookServiceImpl extends ServiceImpl<BookMapper, Book> implements BookService {
}

5. Controller 控制层（核心接口）

package com.book.controller;

import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.book.entity.Book;
import com.book.service.BookService;
import org.springframework.web.bind.annotation.*;

import javax.annotation.Resource;
import java.util.List;

@RestController
@RequestMapping("/book")
public class BookController {

    @Resource
    private BookService bookService;

    // 查询全部图书
    @GetMapping("/list")
    public List<Book> list(){
        return bookService.list();
    }

    // 分页查询
    @GetMapping("/page")
    public IPage<Book> page(@RequestParam(defaultValue = "1") Integer pageNum,
                            @RequestParam(defaultValue = "5") Integer pageSize){
        Page<Book> page = new Page<>(pageNum, pageSize);
        return bookService.page(page);
    }

    // 新增图书
    @PostMapping("/add")
    public boolean add(@RequestBody Book book){
        return bookService.save(book);
    }

    // 根据id查询
    @GetMapping("/{id}")
    public Book getOne(@PathVariable Integer id){
        return bookService.getById(id);
    }

    // 修改图书
    @PutMapping("/update")
    public boolean update(@RequestBody Book book){
        return bookService.updateById(book);
    }

    // 删除图书
    @DeleteMapping("/{id}")
    public boolean delete(@PathVariable Integer id){
        return bookService.removeById(id);
    }
}

6. MyBatis-Plus 分页配置类（必须加，否则分页失效）

新建 config/MyBatisPlusConfig.java

package com.book.config;

import com.baomidou.mybatisplus.annotation.DbType;
import com.baomidou.mybatisplus.extension.plugins.MybatisPlusInterceptor;
import com.baomidou.mybatisplus.extension.plugins.inner.PaginationInnerInterceptor;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
public class MyBatisPlusConfig {
    @Bean
    public MybatisPlusInterceptor mybatisPlusInterceptor(){
        MybatisPlusInterceptor interceptor = new MybatisPlusInterceptor();
        interceptor.addInnerInterceptor(new PaginationInnerInterceptor(DbType.MYSQL));
        return interceptor;
    }
}

五、接口测试

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