SpringBoot集成MyBatis-Plus + MyBatis-Plus（3.5.3版本）代码生成器

河南循中网络科技有限公司 - 精心创作，详细分解，按照步骤，均可成功！

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MyBatis-Plus介绍

MyBatis-Plus是一个MyBatis的增强工具，只是在MyBatis的基础上做了增强却不做改变，MyBatis-Plus支持所有MyBatis原生的特性，所以引入MyBatis-Plus不会对现有的MyBatis构架产生任何影响。

MyBatis-Plus的优点

1. 依赖少：仅仅依赖 MyBatis以及MyBatis-Spring。
2. 损耗小：启动即会自动注入基本CURD，性能基本无损耗，直接面向对象操作。
3. 预防Sql注入：内置 Sql 注入剥离器，有效预防Sql注入攻击 。
4. 通用CRUD操作：内置通用 Mapper、通用 Service，仅仅通过少量配置即可实现单表大部分CRUD操作，更有强大的条件构造器，满足各类使用需求 。
5. 多种主键策略：支持多达4种主键策略（内含分布式唯一ID生成器），可自由配置，完美解决主键问题 。
6. 支持热加载：Mapper对应的XML支持热加载，对于简单的CRUD操作，甚至可以无XML启动。
7. 支持ActiveRecord：支持 ActiveRecord 形式调用，实体类只需继承 Model 类即可实现基本CRUD操作。
8. 支持代码生成：采用代码或者Maven插件可快速生成Mapper、Model、Service、Controller层代码（生成自定义文件，避免开发重复代码），支持模板引擎、有超多自定义配置等。
9. 支持自定义全局通用操作：支持全局通用方法注入（ Write once, use anywhere ）。
10. 支持关键词自动转义：支持数据库关键词（order、key…）自动转义，还可自定义关键词 。
11. 内置分页插件：基于Mybatis物理分页，开发者无需关心具体操作，配置好插件之后，写分页等同于普通List查询。
12. 内置性能分析插件：可输出 Sql 语句以及其执行时间，建议开发测试时启用该功能，能有效解决慢查询 。
13. 内置全局拦截插件：提供全表delete、update操作智能分析阻断，预防误操作。
14. 默认将实体类的类名查找数据库中的表，使用@TableName(value=“table1”)注解指定表名，@TableId指定表主键，若字段与表中字段名保持一致可不加注解。

学习资料

MyBatis-Plus官网
【黑马MyBatisPlus教程全套视频教程，快速精通mybatisplus框架-哔哩哔哩】

SpringBoot集成MyBatis-Plus + MyBatis-Plus代码生成器

MyBatisPlus配置

1. 创建一个新的子模块，存放MyBatis自动化生成的代码，详情请参考SpringBoot系列 - 多模块开发。
   

无需勾选，直接下一步。
2. 配置父pom文件，声明：子模块。

	
    
        
        common
        
        mp
        
        system
    

3. 配置子pom文件，声明：打包类型。

	
    jar

4. 配置子pom文件，引入相关jar包。

	 
    
        1.8
        
        1.18.24
        
        1.2.11
        
        3.5.1
        
        3.5.3
        
        2.3
    

    
    
        
            org.springframework.boot
            spring-boot-starter
        

        
            org.springframework.boot
            spring-boot-starter-test
            test
        

        
        
            org.projectlombok
            lombok
            ${lombok.version}
        

        
        
            mysql
            mysql-connector-java
            runtime
        

        
            com.alibaba
            druid-spring-boot-starter
            ${druid-spring-boot-starter.version}
        

        
        
            com.baomidou
            mybatis-plus-boot-starter
            ${mybatis-plus-boot-starter.version}
        

        
        
            com.baomidou
            mybatis-plus-generator
            ${mybatis-plus-generator.version}
        

        
        
            org.apache.velocity
            velocity-engine-core
            ${velocity-engine-core.version}
        
    

5. 删除配置.properties，替换成.yaml配置。

# 主配置

# 选择环境
spring:
  profiles:
    active: dev

# mybatisPlus
mybatis-plus:
  # 全局配置
  global-config:
    db-config:
      # 主键ID生成策略
      id-type: auto
      # 逻辑删除策略
      logic-delete-field: hide
      logic-not-delete-value: 0
      logic-delete-value: 1

# 开发环境

# 端口号
server:
  port: 80

spring:
  # 数据库
  datasource:
    type: com.alibaba.druid.pool.DruidDataSource
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: 路径
    username: 令牌
    password: 密码

# mybatisPlus
mybatis-plus:
  # 开启mybatisPlus日志（输出到控制台）
  configuration:
    log-impl: org.apache.ibatis.logging.stdout.StdOutImpl

MyBatisPlus代码生成器

1. 创建Generator类，右键直接运行main方法即可！！

package com.xz;

import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.baomidou.mybatisplus.generator.FastAutoGenerator;
import com.baomidou.mybatisplus.generator.engine.VelocityTemplateEngine;

import java.util.ArrayList;
import java.util.List;

public class Generator {

    public static void main(String[] args) {
        /*
            特别注意：生成的时间类型均为：“LocalDateTime”格式，需要假如以下注解方可正常使用
            @JsonFormat(pattern = "yyyy-MM-dd HH:mm:ss")
            @JsonDeserialize(using = LocalDateTimeDeserializer.class)
            @JsonSerialize(using = LocalDateTimeSerializer.class)
        */

        //数据库连接
        String url = "数据库URL";//数据库url
        String username = "令牌";//账号
        String password = "密码";//密码
        String module = "mp";//模块名
        //全局配置参数
        String author = "河南循中网络科技有限公司";//作者
        String outputDir = System.getProperty("user.dir")+"\\"+module+"\\src\\main\\java";//指定输出目录
        //包配置参数
        String parent = "com";//父包名
        String moduleName = "xz";//父包模块名
        String entity = "entity";//Entity 实体类包名
        String mapper = "mapper";//Mapper 包名
        String mapperXml = "mapper";//Mapper XML 包名
        String service = "service";//Service 包名
        String serviceImpl = "service.impl";//Service Impl 包名
        /*String controller = "controller";//Controller 包名*/
        //要生成的数据库表
        List<String> tables = new ArrayList<>();
        tables.add("product");
        //开始生成
        FastAutoGenerator.create(url,username,password)
                //全局配置
                .globalConfig(builder -> {
                    builder.author(author)
                            .outputDir(outputDir)
                            /*.enableSwagger()//开启swagger*/
                            .commentDate("yyyy-MM-dd");//注释日期
                })
                //包配置
                .packageConfig(builder -> {
                    builder.parent(parent)
                            .moduleName(moduleName)
                            .entity(entity)
                            .mapper(mapper)
                            .xml(mapperXml)
                            .service(service)
                            .serviceImpl(serviceImpl)
                            /*.controller(controller)*/;
                })
                //策略配置
                .strategyConfig(builder -> {
                    builder.addInclude(tables)
                            //开启生成实体类
                            .entityBuilder()
                            .enableLombok()//开启 lombok 模型
                            .enableTableFieldAnnotation()//开启生成实体时生成字段注解
                            //开启生成mapper
                            .mapperBuilder()
                            .enableBaseResultMap()//启用 BaseResultMap 生成
                            .superClass(BaseMapper.class)//设置父类
                            .enableMapperAnnotation()//开启 @Mapper 注解
                            .formatMapperFileName("%sMapper")//格式化 mapper 文件名称
                            .formatXmlFileName("%sMapper")//格式化 xml 实现类文件名称
                            //开启生成service及impl
                            .serviceBuilder()
                            .formatServiceFileName("%sService")//格式化 service 接口文件名称
                            .formatServiceImplFileName("%sServiceImpl");//格式化 service 实现类文件名称
                            /*//开启生成controller
                            .controllerBuilder()
                            // 映射路径使用连字符格式，而不是驼峰
                            .enableHyphenStyle()
                            .formatFileName("%sController")//格式化文件名称
                            .enableRestStyle();*/
                })
                .templateEngine(new VelocityTemplateEngine()) // 使用Freemarker引擎模板，默认的是Velocity引擎模板
                .templateConfig(builder -> builder.controller(""))//关闭生成controller
                .execute();
    }
}

解决Java 8 date/time type `java.time.LocalDateTime异常

如果数据库查询的时候有时间字段，并出现以下异常时：

Creating a new SqlSession
SqlSession [org.apache.ibatis.session.defaults.DefaultSqlSession@4f9eeeaa] was not registered for synchronization because synchronization is not active
JDBC Connection [com.mysql.cj.jdbc.ConnectionImpl@3cd18ac8] will not be managed by Spring
==>  Preparing: SELECT product_id,one_classify_id,two_classify_id,three_classify_id,product_name,product_img,product_listimg,product_buying_price,product_original_price,minimum_profit_money,product_stock,product_sales,maximum_purchase,product_state,product_details,product_source,hide,update_time,insert_time FROM product WHERE product_id=? AND hide=0
==> Parameters: 2(Integer)
<==    Columns: product_id, one_classify_id, two_classify_id, three_classify_id, product_name, product_img, product_listimg, product_buying_price, product_original_price, minimum_profit_money, product_stock, product_sales, maximum_purchase, product_state, product_details, product_source, hide, update_time, insert_time
<==        Row: 2, 7, 9, 11, 勤啊, https://yang-1308989375.cos.ap-shanghai.myqcloud.com/upload/common/20220313/9496b05a-d696-4dfc-8dbd-ffaa174db62f.jpg, https://yang-1308989375.cos.ap-shanghai.myqcloud.com/upload/common/20220313/1b26cdf6-c119-4154-b38e-766e910c02ba.jpg,https://yang-1308989375.cos.ap-shanghai.myqcloud.com/upload/common/20220313/7d67c8ba-588f-418b-8417-6058a381beae.jpg,,, 0.5, 1.0, 0.5, 780, 18, null, 0, <<BLOB>>, 阳阳, 0, 2022-05-10 21:41:41, 2022-03-13 16:45:46
<==      Total: 1
Closing non transactional SqlSession [org.apache.ibatis.session.defaults.DefaultSqlSession@4f9eeeaa]
2022-08-07 17:57:07.811 ERROR 19424 --- [p-nio-80-exec-1] o.a.c.c.C.[.[.[/].[dispatcherServlet]    : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is org.springframework.http.converter.HttpMessageConversionException: Type definition error: [simple type, class java.time.LocalDateTime]; nested exception is com.fasterxml.jackson.databind.exc.InvalidDefinitionException: Java 8 date/time type `java.time.LocalDateTime` not supported by default: add Module "com.fasterxml.jackson.datatype:jackson-datatype-jsr310" to enable handling (through reference chain: com.xz.entity.Product["insertTime"])] with root cause

com.fasterxml.jackson.databind.exc.InvalidDefinitionException: Java 8 date/time type `java.time.LocalDateTime` not supported by default: add Module "com.fasterxml.jackson.datatype:jackson-datatype-jsr310" to enable handling (through reference chain: com.xz.entity.Product["insertTime"])
	at com.fasterxml.jackson.databind.exc.InvalidDefinitionException.from(InvalidDefinitionException.java:77) ~[jackson-databind-2.13.3.jar:2.13.3]
	at com.fasterxml.jackson.databind.SerializerProvider.reportBadDefinition(SerializerProvider.java:1300) ~[jackson-databind-2.13.3.jar:2.13.3]
	at com.fasterxml.jackson.databind.ser.impl.UnsupportedTypeSerializer.serialize(UnsupportedTypeSerializer.java:35) ~[jackson-databind-2.13.3.jar:2.13.3]
	at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:728) ~[jackson-databind-2.13.3.jar:2.13.3]
	at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:774) ~[jackson-databind-2.13.3.jar:2.13.3]
	at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:178) ~[jackson-databind-2.13.3.jar:2.13.3]
	at com.fasterxml.jackson.databind.ser.DefaultSerializerProvider._serialize(DefaultSerializerProvider.java:480) ~[jackson-databind-2.13.3.jar:2.13.3]
	at com.fasterxml.jackson.databind.ser.DefaultSerializerProvider.serializeValue(DefaultSerializerProvider.java:319) ~[jackson-databind-2.13.3.jar:2.13.3]
	at com.fasterxml.jackson.databind.ObjectWriter$Prefetch.serialize(ObjectWriter.java:1518) ~[jackson-databind-2.13.3.jar:2.13.3]
	at com.fasterxml.jackson.databind.ObjectWriter.writeValue(ObjectWriter.java:1007) ~[jackson-databind-2.13.3.jar:2.13.3]
	at org.springframework.http.converter.json.AbstractJackson2HttpMessageConverter.writeInternal(AbstractJackson2HttpMessageConverter.java:456) ~[spring-web-5.3.21.jar:5.3.21]
	at org.springframework.http.converter.AbstractGenericHttpMessageConverter.write(AbstractGenericHttpMessageConverter.java:104) ~[spring-web-5.3.21.jar:5.3.21]
	at org.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodProcessor.writeWithMessageConverters(AbstractMessageConverterMethodProcessor.java:290) ~[spring-webmvc-5.3.21.jar:5.3.21]
	at org.springframework.web.servlet.mvc.method.annotation.RequestResponseBodyMethodProcessor.handleReturnValue(RequestResponseBodyMethodProcessor.java:183) ~[spring-webmvc-5.3.21.jar:5.3.21]
	at org.springframework.web.method.support.HandlerMethodReturnValueHandlerComposite.handleReturnValue(HandlerMethodReturnValueHandlerComposite.java:78) ~[spring-web-5.3.21.jar:5.3.21]
	at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:135) ~[spring-webmvc-5.3.21.jar:5.3.21]
	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:895) ~[spring-webmvc-5.3.21.jar:5.3.21]
	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:808) ~[spring-webmvc-5.3.21.jar:5.3.21]
	at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87) ~[spring-webmvc-5.3.21.jar:5.3.21]
	at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1067) ~[spring-webmvc-5.3.21.jar:5.3.21]
	at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:963) ~[spring-webmvc-5.3.21.jar:5.3.21]
	at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006) ~[spring-webmvc-5.3.21.jar:5.3.21]
	at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:898) ~[spring-webmvc-5.3.21.jar:5.3.21]
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:655) ~[tomcat-embed-core-9.0.64.jar:4.0.FR]
	at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883) ~[spring-webmvc-5.3.21.jar:5.3.21]
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:764) ~[tomcat-embed-core-9.0.64.jar:4.0.FR]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:227) ~[tomcat-embed-core-9.0.64.jar:9.0.64]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.64.jar:9.0.64]
	at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) ~[tomcat-embed-websocket-9.0.64.jar:9.0.64]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) ~[tomcat-embed-core-9.0.64.jar:9.0.64]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.64.jar:9.0.64]
	at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201) ~[spring-web-5.3.21.jar:5.3.21]
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:117) ~[spring-web-5.3.21.jar:5.3.21]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) ~[tomcat-embed-core-9.0.64.jar:9.0.64]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.64.jar:9.0.64]
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:197) ~[tomcat-embed-core-9.0.64.jar:9.0.64]
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:97) [tomcat-embed-core-9.0.64.jar:9.0.64]
	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:541) [tomcat-embed-core-9.0.64.jar:9.0.64]
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:135) [tomcat-embed-core-9.0.64.jar:9.0.64]
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92) [tomcat-embed-core-9.0.64.jar:9.0.64]
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:78) [tomcat-embed-core-9.0.64.jar:9.0.64]
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:360) [tomcat-embed-core-9.0.64.jar:9.0.64]
	at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:399) [tomcat-embed-core-9.0.64.jar:9.0.64]
	at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65) [tomcat-embed-core-9.0.64.jar:9.0.64]
	at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:890) [tomcat-embed-core-9.0.64.jar:9.0.64]
	at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1787) [tomcat-embed-core-9.0.64.jar:9.0.64]
	at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) [tomcat-embed-core-9.0.64.jar:9.0.64]
	at org.apache.tomcat.util.threads.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1191) [tomcat-embed-core-9.0.64.jar:9.0.64]
	at org.apache.tomcat.util.threads.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:659) [tomcat-embed-core-9.0.64.jar:9.0.64]
	at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-9.0.64.jar:9.0.64]
	at java.lang.Thread.run(Thread.java:748) [na:1.8.0_181]

解决方案

将项目改为web项目，增加web项目依赖

	<dependency>
	    <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>

mp模块pom文件

<?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>
    <groupId>com.xz</groupId>
    <artifactId>mp</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>mp</name>
    <description>河南循中网络科技有限公司 - MyBatis-Plus自动化</description>

    <!-- 子模块打包类型必须为jar -->
    <packaging>jar</packaging>

    <!-- parent指明继承关系，给出被继承的父项目的具体信息 -->
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.7.1</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

    <!-- 版本控制 -->
    <properties>
        <java.version>1.8</java.version>
        <!-- 实体类注解 -->
        <lombok.version>1.18.24</lombok.version>
        <!-- 数据库 -->
        <druid-spring-boot-starter.version>1.2.11</druid-spring-boot-starter.version>
        <!-- mybatis plus -->
        <mybatis-plus-boot-starter.version>3.5.1</mybatis-plus-boot-starter.version>
        <!-- mybatis代码生成器 -->
        <mybatis-plus-generator.version>3.5.3</mybatis-plus-generator.version>
        <!-- mybatis代码生成器，所需要的“velocity模板引擎” -->
        <velocity-engine-core.version>2.3</velocity-engine-core.version>
        <!-- swagger -->
        <springfox-boot-starter.version>3.0.0</springfox-boot-starter.version>
    </properties>

    <!-- 引入的jar包 -->
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>

        <!-- 实体类注解 -->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>${lombok.version}</version>
        </dependency>

        <!-- 数据库 -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>

        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid-spring-boot-starter</artifactId>
            <version>${druid-spring-boot-starter.version}</version>
        </dependency>

        <!-- mybatis plus -->
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>${mybatis-plus-boot-starter.version}</version>
        </dependency>

        <!-- mybatis代码生成器 -->
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-generator</artifactId>
            <version>${mybatis-plus-generator.version}</version>
        </dependency>

        <!-- mybatis代码生成器，所需要的“velocity模板引擎” -->
        <dependency>
            <groupId>org.apache.velocity</groupId>
            <artifactId>velocity-engine-core</artifactId>
            <version>${velocity-engine-core.version}</version>
        </dependency>

        <!-- swagger -->
        <dependency>
            <groupId>io.springfox</groupId>
            <artifactId>springfox-boot-starter</artifactId>
            <version>${springfox-boot-starter.version}</version>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

在实体类中，增加如下注解

	@JsonFormat(pattern = "yyyy-MM-dd HH:mm:ss")
    @JsonDeserialize(using = LocalDateTimeDeserializer.class)
    @JsonSerialize(using = LocalDateTimeSerializer.class)

解决测试

无出现异常bug，问题解决！