Springboot整合MybatisPlus完整详解（最新）~

迈不过友情╰ 2023-02-13 05:56 88阅读 0赞

## 新建springboot项目 ##

开发工具：idea2019.2,maven3

![format_png][]  
![format_png 1][]

### 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>
            
            <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：  
![format_png 2][]  
执行GeneratorCodeConfig.java文件，输入表名user：  
![format_png 3][]  
解决方法：在数据库连接中配置添加allowPublicKeyRetrieval=true  
![format_png 4][]

![format_png 5][]  
查看生成的文件；  
![format_png 6][]

### 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：  
![format_png 7][]  
![format_png 8][]  
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">
    
        
        <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：  
![format_png 9][]

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

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