Springboot整合MybatisPlus（超详细）完整教程~

2022-06-17 02:43:52

新建springboot项目

开发工具：idea2019.2,maven3

pom.xml

    <dependency>

            <groupId>org.springframework.boot</groupId>

            <artifactId>spring-boot-starter</artifactId>

        </dependency>

        <dependency>

            <groupId>org.springframework.boot</groupId>

            <artifactId>spring-boot-starter-web</artifactId>

        </dependency>

        <dependency>

            <groupId>mysql</groupId>

            <artifactId>mysql-connector-java</artifactId>

            <scope>runtime</scope>

        </dependency>

        <dependency>

            <groupId>org.projectlombok</groupId>

            <artifactId>lombok</artifactId>

            <optional>true</optional>

        </dependency>

        <!-- mybatis plus 代码生成器 -->

        <dependency>

            <groupId>com.baomidou</groupId>

            <artifactId>mybatis-plus-boot-starter</artifactId>

            <version>3.2.0</version>

        </dependency>

        <dependency>

            <groupId>com.baomidou</groupId>

            <artifactId>mybatis-plus-generator</artifactId>

            <version>3.2.0</version>

        </dependency>

        <dependency>

            <groupId>org.freemarker</groupId>

            <artifactId>freemarker</artifactId>

            <version>2.3.28</version>

        </dependency>

        <dependency>

            <groupId>com.alibaba</groupId>

            <artifactId>fastjson</artifactId>

            <version>1.2.47</version>

        </dependency>

application.yml:

server:

  port: 8081

  servlet:

    context-path: /

spring:

  datasource:

    driver-class-name: com.mysql.cj.jdbc.Driver

    url: jdbc:mysql://127.0.0.1:3306/demo?serverTimezone=Asia/Shanghai&useUnicode=true&characterEncoding=utf-8&zeroDateTimeBehavior=convertToNull&useSSL=false&allowPublicKeyRetrieval=true

    username: root

    password: lyja

  jackson:

    date-format: yyyy-MM-dd HH:mm:ss

    time-zone: GMT+8

    serialization:

      write-dates-as-timestamps: false

mybatis-plus:

  configuration:

    map-underscore-to-camel-case: true

    auto-mapping-behavior: full

    log-impl: org.apache.ibatis.logging.stdout.StdOutImpl

  mapper-locations: classpath*:mapper/**/*Mapper.xml

  global-config:

    # 逻辑删除配置

    db-config:

      # 删除前

      logic-not-delete-value: 1

      # 删除后

      logic-delete-value: 0

mybatisplus分页插件MybatisPlusConfig：

package com.example.conf;

import com.baomidou.mybatisplus.extension.plugins.PaginationInterceptor;

import org.springframework.context.annotation.Bean;

import org.springframework.context.annotation.Configuration;

/**

 * 配置分页插件

 *

 */

@Configuration

public class MybatisPlusConfig {

    /**

     * 分页插件

     */

    @Bean

    public PaginationInterceptor paginationInterceptor() {

        return new PaginationInterceptor();

    }

}

mybatisplus自动生成代码GeneratorCodeConfig.java：

package com.example.conf;

import com.baomidou.mybatisplus.core.exceptions.MybatisPlusException;

import com.baomidou.mybatisplus.core.toolkit.StringUtils;

import com.baomidou.mybatisplus.generator.AutoGenerator;

import com.baomidou.mybatisplus.generator.config.*;

import com.baomidou.mybatisplus.generator.config.rules.NamingStrategy;

import com.baomidou.mybatisplus.generator.engine.FreemarkerTemplateEngine;

import java.util.Scanner;

/**

 * 自动生成mybatisplus的相关代码

 */

public class GeneratorCodeConfig {

    public static String scanner(String tip) {

        Scanner scanner = new Scanner(System.in);

        StringBuilder help = new StringBuilder();

        help.append("请输入" + tip + "：");

        System.out.println(help.toString());

        if (scanner.hasNext()) {

            String ipt = scanner.next();

            if (StringUtils.isNotEmpty(ipt)) {

                return ipt;

            }

        }

        throw new MybatisPlusException("请输入正确的" + tip + "！");

    }

    public static void main(String[] args) {

        // 代码生成器

        AutoGenerator mpg = new AutoGenerator();

        // 全局配置

        GlobalConfig gc = new GlobalConfig();

        String projectPath = System.getProperty("user.dir");

        gc.setOutputDir(projectPath + "/src/main/java");

        gc.setAuthor("astupidcoder");

        gc.setOpen(false);

        //实体属性 Swagger2 注解

        gc.setSwagger2(false);

        mpg.setGlobalConfig(gc);

        // 数据源配置

        DataSourceConfig dsc = new DataSourceConfig();

        dsc.setUrl("jdbc:mysql://127.0.0.1:3306/demo?serverTimezone=UTC&useUnicode=true&characterEncoding=utf-8&zeroDateTimeBehavior=convertToNull&useSSL=false&allowPublicKeyRetrieval=true");

        dsc.setDriverName("com.mysql.cj.jdbc.Driver");

        dsc.setUsername("root");

        dsc.setPassword("lyja");

        mpg.setDataSource(dsc);

        // 包配置

        PackageConfig pc = new PackageConfig();

//        pc.setModuleName(scanner("模块名"));

        pc.setParent("com.example");

        pc.setEntity("model.auto");

        pc.setMapper("mapper.auto");

        pc.setService("service");

        pc.setServiceImpl("service.impl");

        mpg.setPackageInfo(pc);

        // 自定义配置

//        InjectionConfig cfg = new InjectionConfig() {

//            @Override

//            public void initMap() {

//                // to do nothing

//            }

//        };

        // 如果模板引擎是 freemarker

//        String templatePath = "/templates/mapper.xml.ftl";

        // 如果模板引擎是 velocity

        // String templatePath = "/templates/mapper.xml.vm";

        // 自定义输出配置

//        List<FileOutConfig> focList = new ArrayList<>();

        // 自定义配置会被优先输出

//        focList.add(new FileOutConfig(templatePath) {

//            @Override

//            public String outputFile(TableInfo tableInfo) {

//                // 自定义输出文件名 ， 如果你 Entity 设置了前后缀、此处注意 xml 的名称会跟着发生变化！！

//                return projectPath + "/src/main/resources/mapper/" + pc.getModuleName()

//                        + "/" + tableInfo.getEntityName() + "Mapper" + StringPool.DOT_XML;

//            }

//        });

        /*

        cfg.setFileCreate(new IFileCreate() {

            @Override

            public boolean isCreate(ConfigBuilder configBuilder, FileType fileType, String filePath) {

                // 判断自定义文件夹是否需要创建

                checkDir("调用默认方法创建的目录");

                return false;

            }

        });

        */

//        cfg.setFileOutConfigList(focList);

//        mpg.setCfg(cfg);

        // 配置模板

        TemplateConfig templateConfig = new TemplateConfig();

        // 配置自定义输出模板

        //指定自定义模板路径，注意不要带上.ftl/.vm, 会根据使用的模板引擎自动识别

        // templateConfig.setEntity("templates/entity2.java");

        // templateConfig.setService();

        // templateConfig.setController();

        templateConfig.setXml(null);

        mpg.setTemplate(templateConfig);

        // 策略配置

        StrategyConfig strategy = new StrategyConfig();

        strategy.setNaming(NamingStrategy.underline_to_camel);

        strategy.setColumnNaming(NamingStrategy.underline_to_camel);

        strategy.setSuperEntityClass("com.baomidou.mybatisplus.extension.activerecord.Model");

        strategy.setEntityLombokModel(true);

        strategy.setRestControllerStyle(true);

        strategy.setEntityLombokModel(true);

        // 公共父类

//        strategy.setSuperControllerClass("com.baomidou.ant.common.BaseController");

        // 写于父类中的公共字段

//        strategy.setSuperEntityColumns("id");

        strategy.setInclude(scanner("表名，多个英文逗号分割").split(","));

        strategy.setControllerMappingHyphenStyle(true);

        strategy.setTablePrefix(pc.getModuleName() + "_");

        mpg.setStrategy(strategy);

        mpg.setTemplateEngine(new FreemarkerTemplateEngine());

        mpg.execute();

    }

}

测试

建表：

执行GeneratorCodeConfig.java文件，输入表名user：

解决方法：在数据库连接中配置添加allowPublicKeyRetrieval=true

查看生成的文件；

添加扫描mapper注解

启动springboot的application启动类：会报错，提示找不到mapper文件，我们需要在springboot启动类上添加扫描mapper的注解：

package com.example;

import org.mybatis.spring.annotation.MapperScan;

import org.springframework.boot.SpringApplication;

import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication

@MapperScan("com.example.mapper")

public class DemoApplication {

    public static void main(String[] args) {

        SpringApplication.run(DemoApplication.class, args);

    }

}

UserController.java中新增接口：

  @Autowired

    private IUserService userService;

    @PostMapping("/getUser")

    public User getUser(){

        return userService.getById(1);

    }

postman测试：

没问题。

上面是mybatisplus测试成功，下面我们继续测试我们自己写的sql是否成功。

在resources目录下新建mapper文件夹，新建UserMapper.xml文件：

<?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">

<mapper namespace="com.example.mapper.auto.UserMapper">

    <!-- 查找用户信息 -->

    <select id="findAllUser" resultType="com.example.model.auto.User">

       select * from user

    </select>

</mapper>

UserMapper.java

package com.example.mapper.auto;

import com.baomidou.mybatisplus.core.mapper.BaseMapper;

import com.example.model.auto.User;

import java.util.List;

/**

 * <p>

 *  Mapper 接口

 * </p>

 *

 * @author astupidcoder

 * @since 2020-05-13

 */

public interface UserMapper extends BaseMapper<User> {

    public List<User>findAllUser();

}

IUserService:

package com.example.service;

import com.baomidou.mybatisplus.extension.service.IService;

import com.example.model.auto.User;

import java.util.List;

/**

 * <p>

 *  服务类

 * </p>

 *

 * @author astupidcoder

 * @since 2020-05-13

 */

public interface IUserService extends IService<User> {

    public List<User> findAllUser();

}

UseServiceImpl.java:

package com.example.service.impl;

import com.example.model.auto.User;

import com.example.mapper.auto.UserMapper;

import com.example.service.IUserService;

import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.stereotype.Service;

import java.util.List;

/**

 * <p>

 *  服务实现类

 * </p>

 *

 * @author astupidcoder

 * @since 2020-05-13

 */

@Service

public class UserServiceImpl extends ServiceImpl<UserMapper, User> implements IUserService {

    @Autowired

    private UserMapper userMapper;

    @Override

    public List<User> findAllUser() {

        return userMapper.findAllUser();

    }

}

UserController.java:

package com.example.controller;

import com.example.model.auto.User;

import com.example.service.IUserService;

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.web.bind.annotation.PostMapping;

import org.springframework.web.bind.annotation.RequestMapping;

import org.springframework.web.bind.annotation.RestController;

import java.util.List;

/**

 * <p>

 *  前端控制器

 * </p>

 *

 * @author astupidcoder

 * @since 2020-05-13

 */

@RestController

@RequestMapping("/user")

public class UserController {

    @Autowired

    private IUserService userService;

    @PostMapping("/getUser")

    public User getUser(){

        return userService.getById(1);

    }

    @PostMapping("/findAllUser")

    public List<User> findAllUser(){

        return userService.findAllUser();

    }

}

测试findAllUser接口：

常用的工具类：

ResultInfo.java

package com.example.conf;

import lombok.Data;

import java.io.Serializable;

/**

 *返回结果类统一封装

 */

@Data

public class ResultInfo implements Serializable {

    // 状态码

    private Integer code;

    // 消息

    private String message;

    // 数据对象

    private Object result;

    private Integer total;

    /**

     * 无参构造器

     */

    public ResultInfo() {

        super();

    }

    public ResultInfo(Status status) {

        super();

        this.code = status.code;

        this.message = status.message;

    }

    public ResultInfo result(Object result) {

        this.result = result;

        return this;

    }

    public ResultInfo message(String message) {

        this.message = message;

        return this;

    }

    public ResultInfo total(Integer total) {

        this.total = total;

        return this;

    }

    /**

     * 只返回状态，状态码，消息

     *

     * @param code

     * @param message

     */

    public ResultInfo(Integer code, String message) {

        super();

        this.code = code;

        this.message = message;

    }

    /**

     * 只返回状态，状态码，数据对象

     *

     * @param code

     * @param result

     */

    public ResultInfo(Integer code, Object result) {

        super();

        this.code = code;

        this.result = result;

    }

    /**

     * 返回全部信息即状态，状态码，消息，数据对象

     *

     * @param code

     * @param message

     * @param result

     */

    public ResultInfo(Integer code, String message, Object result) {

        super();

        this.code = code;

        this.message = message;

        this.result = result;

    }

}

Status.java

package com.example.conf;

/**

 * 枚举类对象

 */

public enum Status {

    // 公共

    SUCCESS(2000, "成功"),

    UNKNOWN_ERROR(9998,"未知异常"),

    SYSTEM_ERROR(9999, "系统异常"),

    INSUFFICIENT_PERMISSION(4003, "权限不足"),

    WARN(9000, "失败"),

    REQUEST_PARAMETER_ERROR(1002, "请求参数错误"),

    // 登录

    LOGIN_EXPIRE(2001, "未登录或者登录失效"),

    LOGIN_CODE_ERROR(2002, "登录验证码错误"),

    LOGIN_ERROR(2003, "用户名不存在或密码错误"),

    LOGIN_USER_STATUS_ERROR(2004, "用户状态不正确"),

    LOGOUT_ERROR(2005, "退出失败，token不存在"),

    LOGIN_USER_NOT_EXIST(2006, "该用户不存在"),

    LOGIN_USER_EXIST(2007, "该用户已存在");

    public int code;

    public String message;

    Status(int code, String message) {

        this.code = code;

        this.message = message;

    }

}

附录：

一份详尽的yml配置文件(关于数据源的配置比较详尽)：

server:

  port: 8085

  servlet:

    context-path: /test

spring:

  #redis集群

  redis:

    host: 127.0.0.1

    port: 6379

    timeout: 20000

    #    集群环境打开下面注释，单机不需要打开

    #    cluster:

    #      集群信息

    #      nodes: xxx.xxx.xxx.xxx:xxxx,xxx.xxx.xxx.xxx:xxxx,xxx.xxx.xxx.xxx:xxxx

    #      #默认值是5 一般当此值设置过大时，容易报：Too many Cluster redirections

    #      maxRedirects: 3

    password: lyja

    application:

      name: test

    jedis:

      pool:

        max-active: 8

        min-idle: 0

        max-idle: 8

        max-wait: -1

    database: 0

  autoconfigure:

    exclude: com.alibaba.druid.spring.boot.autoconfigure.DruidDataSourceAutoConfigure

  datasource:

    dynamic:

      #设置默认的数据源或者数据源组,默认值即为master

      primary: master

      strict: false

      datasource:

        master:

          driver-class-name: com.mysql.cj.jdbc.Driver

          url: jdbc:mysql://127.0.0.1:3306/test?serverTimezone=Asia/Shanghai&useUnicode=true&characterEncoding=utf-8&zeroDateTimeBehavior=convertToNull&useSSL=false

          username: root

          password: lyja

    # 数据源配置

    druid:

      # druid连接池监控

      stat-view-servlet:

        enabled: true

        url-pattern: /druid/*

        login-username: admin

        login-password: admin

        # 初始化时建立物理连接的个数

        initial-size: 5

        # 最大连接池数量

        max-active: 30

        # 最小连接池数量

        min-idle: 5

        # 获取连接时最大等待时间，单位毫秒

        max-wait: 60000

        # 配置间隔多久才进行一次检测，检测需要关闭的空闲连接，单位是毫秒

        time-between-eviction-runs-millis: 60000

        # 连接保持空闲而不被驱逐的最小时间

        min-evictable-idle-time-millis: 300000

        # 用来检测连接是否有效的sql，要求是一个查询语句

        validation-query: select count(*) from dual

        # 建议配置为true，不影响性能，并且保证安全性。申请连接的时候检测，如果空闲时间大于timeBetweenEvictionRunsMillis，执行validationQuery检测连接是否有效。

        test-while-idle: true

        # 申请连接时执行validationQuery检测连接是否有效，做了这个配置会降低性能。

        test-on-borrow: false

        # 归还连接时执行validationQuery检测连接是否有效，做了这个配置会降低性能。

        test-on-return: false

        # 是否缓存preparedStatement，也就是PSCache。PSCache对支持游标的数据库性能提升巨大，比如说oracle。在mysql下建议关闭。

        pool-prepared-statements: false

        # 要启用PSCache，必须配置大于0，当大于0时，poolPreparedStatements自动触发修改为true。

        max-pool-prepared-statement-per-connection-size: 50

        # 配置监控统计拦截的filters，去掉后监控界面sql无法统计

        filters: stat,wall

        # 通过connectProperties属性来打开mergeSql功能；慢SQL记录

        connection-properties:

          druid.stat.mergeSql: true

          druid.stat.slowSqlMillis: 500

        # 合并多个DruidDataSource的监控数据

        use-global-data-source-stat: true

        filter:

          stat:

            log-slow-sql: true

            slow-sql-millis: 1000

            merge-sql: true

          wall:

            config:

              multi-statement-allow: true

  servlet:

    multipart:

      # 开启 multipart 上传功能

      enabled: true

      # 文件写入磁盘的阈值

      file-size-threshold: 2KB

      # 最大文件大小

      max-file-size: 200MB

      # 最大请求大小

      max-request-size: 215MB

mybatis-plus:

  configuration:

    map-underscore-to-camel-case: true

    auto-mapping-behavior: full

    log-impl: org.apache.ibatis.logging.stdout.StdOutImpl

  mapper-locations: classpath*:mapper/**/*Mapper.xml

  global-config:

    # 逻辑删除配置

    db-config:

      # 删除前

      logic-not-delete-value: 1

      # 删除后

      logic-delete-value: 0

logging:

  level:

    root: info

    com.example: debug

码农公寓