第六篇 : SpringBoot 整合 mybatis-plus

这一篇我们讲解如何在springboot下整合mybatis-plus，并访问数据库。
MyBatis-Plus（简称 MP）是一个 MyBatis 的增强工具，在 MyBatis 的基础上只做增强不做改变，为简化开发、提高效率而生。

对于 mybatis-plus 的使用，可以参照官网http://mp.baomidou.com/，这里我就不讲解了。

一、创建数据库表

DROP TABLE IF EXISTS `tb_employee`;
CREATE TABLE `tb_employee` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `lastName` varchar(255) DEFAULT NULL,
  `email` varchar(255) DEFAULT NULL,
  `gender` int(2) DEFAULT NULL,
  `d_id` int(11) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

二、创建项目

创建一个项目springboot-mybatis

1、pom.xml

<?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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.gf</groupId>
    <artifactId>springboot-mybatis</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>springboot-mybatis</name>
    <description>Demo project for Spring Boot</description>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.0.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <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>3.0.1</version>
        </dependency>

        <dependency>
            <groupId>org.apache.velocity</groupId>
            <artifactId>velocity</artifactId>
            <version>1.7</version>
        </dependency>

        <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>
            </plugin>
        </plugins>
    </build>


</project>

2. 代码生成器

AutoGenerator 是 MyBatis-Plus 的代码生成器，通过 AutoGenerator 可以快速生成 Entity、Mapper、Mapper XML、Service、Controller 等各个模块的代码，极大的提升了开发效率。

1. mapper.xml.vm

在resources/templates 下创建 Mapper XML的生成模板

<?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="${package.Mapper}.${table.mapperName}">

#if(${enableCache})
    <!-- 开启二级缓存 -->
    <cache type="org.mybatis.caches.ehcache.LoggingEhcache"/>

#end
#if(${baseResultMap})
    <!-- 通用查询映射结果 -->
    <resultMap id="BaseResultMap" type="${package.Entity}.${entity}">
#foreach($field in ${table.fields})
#if(${field.keyFlag})##生成主键排在第一位
        <id column="${field.name}" property="${field.propertyName}" />
#end
#end
#foreach($field in ${table.commonFields})##生成公共字段
    <result column="${field.name}" property="${field.propertyName}" />
#end
#foreach($field in ${table.fields})
#if(!${field.keyFlag})##生成普通字段
        <result column="${field.name}" property="${field.propertyName}" />
#end
#end
    </resultMap>

#end
#if(${baseColumnList})
    <!-- 通用查询结果列 -->
    <sql id="Base_Column_List">
#foreach($field in ${table.commonFields})
        ${field.name},
#end
        ${table.fieldNames}
    </sql>

#end
</mapper>

2. CodeGenerator

package com.gf.config;


import com.baomidou.mybatisplus.annotation.DbType;
import com.baomidou.mybatisplus.core.toolkit.StringPool;
import com.baomidou.mybatisplus.generator.AutoGenerator;
import com.baomidou.mybatisplus.generator.InjectionConfig;
import com.baomidou.mybatisplus.generator.config.DataSourceConfig;
import com.baomidou.mybatisplus.generator.config.FileOutConfig;
import com.baomidou.mybatisplus.generator.config.GlobalConfig;
import com.baomidou.mybatisplus.generator.config.PackageConfig;
import com.baomidou.mybatisplus.generator.config.StrategyConfig;
import com.baomidou.mybatisplus.generator.config.TemplateConfig;
import com.baomidou.mybatisplus.generator.config.po.TableInfo;
import com.baomidou.mybatisplus.generator.config.rules.NamingStrategy;
import java.util.ArrayList;
import java.util.List;


public class CodeGenerator {

    public static void main(String[] args) throws InterruptedException {
        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.setFileOverride(true);
        gc.setActiveRecord(true);
        gc.setEnableCache(false);// XML 二级缓存
        gc.setBaseResultMap(true);// XML ResultMap
        gc.setBaseColumnList(true);// XML columList
        gc.setOpen(false);
        gc.setAuthor("gf");


        // 自定义文件命名，注意 %s 会自动填充表实体属性！
        gc.setMapperName("%sMapper");
        gc.setXmlName("%sMapper");
        gc.setServiceName("%sService");
        gc.setServiceImplName("%sServiceImpl");
        gc.setControllerName("%sController");

        mpg.setGlobalConfig(gc);

        // 数据源配置
        DataSourceConfig dsc = new DataSourceConfig();
        dsc.setDbType( DbType.MYSQL);
        dsc.setDriverName("com.mysql.jdbc.Driver");
        dsc.setUrl("jdbc:mysql://127.0.0.1:3306/test?useSSL=false");
        dsc.setUsername("xxxxxx");
        dsc.setPassword("xxxxxx");
        mpg.setDataSource(dsc);

        // 包配置
        PackageConfig pc = new PackageConfig();
        pc.setParent("com.gf");
        pc.setController( "controller");
        pc.setEntity( "entity" );
        //pc.setModuleName("test");
        mpg.setPackageInfo(pc);

        // 自定义配置
        InjectionConfig cfg = new InjectionConfig() {
            @Override
            public void initMap() {
                // to do nothing
            }
        };
        List<FileOutConfig> focList = new ArrayList<>();
        focList.add(new FileOutConfig("/templates/mapper.xml.vm") {
            @Override
            public String outputFile(TableInfo tableInfo) {
                // 自定义输入文件名称
                return projectPath + "/src/main/resources/mapper/"
                        + tableInfo.getEntityName() + "Mapper" + StringPool.DOT_XML;
            }
        });
        cfg.setFileOutConfigList(focList);
        mpg.setCfg(cfg);
        mpg.setTemplate(new TemplateConfig().setXml(null));

        // 策略配置
        StrategyConfig strategy = new StrategyConfig();
        //此处可以修改为您的表前缀
        strategy.setTablePrefix(new String[] { "tb_"});
        // 表名生成策略
        strategy.setNaming(NamingStrategy.underline_to_camel);
        // 需要生成的表
        strategy.setInclude(new String[] { "tb_employee" });
        // 排除生成的表
        //strategy.setExclude(new String[]{"test"});
        strategy.setEntityLombokModel( true );

        mpg.setStrategy(strategy);

        // 执行生成
        mpg.execute();
    }

}

我运行 CodeGenerator 会发现，我么需要的 entity、mapper、service、controller 都有了，而且mybatis-plus 为我们封装了很对常用的方法 ，大大的提到了我们的开发效率

3. application.properties

spring.datasource.url=jdbc:mysql://localhost:3306/test
spring.datasource.username=xxxxxx
spring.datasource.password=xxxxxx
spring.datasource.driver-class-name=com.mysql.jdbc.Driver

4. EmployeeController

@RestController
@RequestMapping("/employee")
public class EmployeeController {


    @Autowired
    EmployeeService employeeService;

    @RequestMapping(value = "/list", method = RequestMethod.GET)
    public List<Employee> getEmployees() {
        return employeeService.list( null );
    }

    @RequestMapping(value = "/{id}", method = RequestMethod.GET)
    public Employee getEmployeeById(@PathVariable("id") int id) {
        return employeeService.getById( id );
    }

    @RequestMapping(value = "/{id}", method = RequestMethod.PUT)
    public String updateEmployee(@PathVariable("id") int id, @RequestParam(value = "lastName", required = true) String lastName,
                                @RequestParam(value = "email", required = true) String email , @RequestParam(value = "gender", required = true) int gender , @RequestParam(value = "dId", required = true) int dId) {
        Employee employee = new Employee();
        employee.setId( id );
        employee.setLastName( "张" );
        employee.setEmail( "zhang@163.com" );
        employee.setGender( 1 );
        employee.setDId( 1 );

        boolean b = employeeService.updateById( employee );

        if (b) {
            return "update success";
        } else {
            return "update fail";
        }

    }

    @RequestMapping(value = "/{id}", method = RequestMethod.DELETE)
    public String delete(@PathVariable(value = "id")int id) {
        boolean b = employeeService.removeById( id );

        if(b) {
            return "delete success";
        }else {
            return "delete fail";
        }

    }

    @RequestMapping(value = "", method = RequestMethod.POST)
    public String postEmployee(@RequestParam(value = "lastName", required = true) String lastName,
                               @RequestParam(value = "email", required = true) String email , @RequestParam(value = "gender", required = true) int gender , @RequestParam(value = "dId", required = true) int dId) {

        Employee employee = new Employee();
        employee.setLastName( "王" );
        employee.setEmail( "wang@163.com" );
        employee.setGender( 2 );
        employee.setDId( 2 );
        boolean b = employeeService.save( employee );

        if(b) {
            return "sava success";
        }else {
            return "sava fail";
        }

    }


}

源码下载：https://github.com/gf-huanchupk/SpringBootLearning