SpringBoot（十六）：SpringBoot整合Mybatis-Plus

àì夳堔傛蜴生んèń 2022-05-23 08:46 250阅读 0赞

> Mybatis-Plus 总的来说比Mybatis Generator更加好用，公司自己搭的框架也是用的这个，还算方便。

本节版本虽然只用到了基本特性，但可以满足大部分的增删改查。

#### 一、环境准备 ####

*  SpringBoot 1.5.10.RELEASE
 *  Mybatis-Plus 2.1.9

Mybatis-Plus 官方地址：http://mp.baomidou.com/

pom依赖，为了方便，全贴出来吧：

<?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>cn.saytime</groupId>
    	<artifactId>springboot-mybatis-plus</artifactId>
    	<version>0.0.1-SNAPSHOT</version>
    	<packaging>jar</packaging>
    
    	<name>springboot-mybatis-plus</name>
    	<description>SpringBoot With Mybatis Plus</description>
    
    	<parent>
    		<groupId>org.springframework.boot</groupId>
    		<artifactId>spring-boot-starter-parent</artifactId>
    		<version>1.5.10.RELEASE</version>
    		<relativePath/> 
    	</parent>
    
    	<properties>
    		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    		<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
    		<java.version>1.8</java.version>
    		<log4j.version>1.3.8.RELEASE</log4j.version>
    		<druid.version>1.0.26</druid.version>
    		<mybatis-plus.version>2.1.9</mybatis-plus.version>
    		<mybatisplus-spring-boot-starter.version>1.0.5</mybatisplus-spring-boot-starter.version>
    	</properties>
    
    	<dependencies>
    		<dependency>
    			<groupId>org.springframework.boot</groupId>
    			<artifactId>spring-boot-starter</artifactId>
    		</dependency>
    
    		
    		<dependency>
    			<groupId>com.alibaba</groupId>
    			<artifactId>druid</artifactId>
    			<version>${druid.version}</version>
    		</dependency>
    
    		
    		<dependency>
    			<groupId>mysql</groupId>
    			<artifactId>mysql-connector-java</artifactId>
    			<scope>runtime</scope>
    		</dependency>
    
    		
    		<dependency>
    			<groupId>com.baomidou</groupId>
    			<artifactId>mybatisplus-spring-boot-starter</artifactId>
    			<version>${mybatisplus-spring-boot-starter.version}</version>
    		</dependency>
    		<dependency>
    			<groupId>com.baomidou</groupId>
    			<artifactId>mybatis-plus</artifactId>
    			<version>${mybatis-plus.version}</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>

#### 二、项目结构 ####

先列出最初始的项目结构，至于model，mapper，service，mapper xml，controller之后都自动生成出来。

![这里写图片描述][70]

#### 三、代码详情 ####

数据准备

在test库建一个user表。

CREATE TABLE `user` (
      `id` bigint(20) NOT NULL COMMENT '用户ID',
      `name` varchar(50) DEFAULT NULL COMMENT '用户名',
      PRIMARY KEY (`id`)
    ) ENGINE=InnoDB DEFAULT CHARSET=utf8 COMMENT='用户表'
    
    insert into `user` (`id`, `name`) values('1','张三');
    insert into `user` (`id`, `name`) values('2','李四');
    insert into `user` (`id`, `name`) values('3','王五');

application.yml

> 注意配置的几个路径换成你的项目的。

spring:
      datasource:
        driver-class-name: com.mysql.jdbc.Driver
        url: jdbc:mysql://127.0.0.1:3306/test?useUnicode=true&characterEncoding=utf8&autoReconnect=true&useSSL=false
        username: root
        password: root
    
    
    mybatis-plus:
      # 如果是放在src/main/java目录下 classpath:/com/yourpackage/*/mapper/*Mapper.xml
      # 如果是放在resource目录 classpath:/mapper/*Mapper.xml
      mapper-locations: classpath:mybatis/mappers/*Mapper.xml
      #实体扫描，多个package用逗号或者分号分隔
      typeAliasesPackage: cn.saytime.model
      global-config:
        #主键类型  0:"数据库ID自增", 1:"用户输入ID",2:"全局唯一ID (数字类型唯一ID)", 3:"全局唯一ID UUID";
        id-type: 0
        #字段策略 0:"忽略判断",1:"非 NULL 判断"),2:"非空判断"
        field-strategy: 1
        #驼峰下划线转换
        #db-column-underline: true
        #刷新mapper 调试神器
        #refresh-mapper: true
        #数据库大写下划线转换
        #capital-mode: true
        # Sequence序列接口实现类配置
        #key-generator: com.baomidou.mybatisplus.incrementer.OracleKeyGenerator
        #逻辑删除配置（下面3个配置）
        #logic-delete-value: 1
        #logic-not-delete-value: 0
        #sql-injector: com.baomidou.mybatisplus.mapper.LogicSqlInjector
        #自定义填充策略接口实现
        #meta-object-handler: com.baomidou.springboot.MyMetaObjectHandler
      configuration:
        map-underscore-to-camel-case: true
        cache-enabled: false
        #配置JdbcTypeForNull
        jdbc-type-for-null: 'null'

druid.properties

#--------------------------
    # 下面为连接池的补充设置，应用到上面所有数据源中
    # 初始化大小，最小，最大
    spring.datasource.initialSize=5
    spring.datasource.minIdle=1
    spring.datasource.maxActive=50
    # 配置获取连接等待超时的时间
    spring.datasource.maxWait=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
    spring.datasource.timeBetweenEvictionRunsMillis=60000
    # 配置一个连接在池中最小生存的时间，单位是毫秒
    spring.datasource.minEvictableIdleTimeMillis=300000
    spring.datasource.validationQuery=SELECT 1 FROM DUAL
    spring.datasource.testWhileIdle=true
    spring.datasource.testOnBorrow=false
    spring.datasource.testOnReturn=false
    # 打开PSCache，并且指定每个连接上PSCache的大小
    spring.datasource.poolPreparedStatements=false
    #spring.datasource.maxPoolPreparedStatementPerConnectionSize=20
    # 配置监控统计拦截的filters，去掉后监控界面sql无法统计，'wall'用于防火墙
    spring.datasource.filters=stat,wall,log4j
    # 通过connectProperties属性来打开mergeSql功能；慢SQL记录
    spring.datasource.connectionProperties=druid.stat.mergeSql=true;druid.stat.slowSqlMillis=5000
    # 合并多个DruidDataSource的监控数据
    #spring.datasource.useGlobalDataSourceStat=true

DruidConfiguration.java

由于这里不用controller接口方式演示，使用test演示，没引入starter-web，所以druid的servlet暂时注释，有要用的可以打开，加入依赖即可。

package cn.saytime.config;
    
    import com.alibaba.druid.pool.DruidDataSource;
    import com.alibaba.druid.support.http.StatViewServlet;
    import com.alibaba.druid.support.http.WebStatFilter;
    import org.springframework.boot.context.properties.ConfigurationProperties;
    import org.springframework.boot.web.servlet.FilterRegistrationBean;
    import org.springframework.boot.web.servlet.ServletRegistrationBean;
    import org.springframework.context.annotation.Bean;
    import org.springframework.context.annotation.Configuration;
    import org.springframework.context.annotation.PropertySource;
    
    import javax.sql.DataSource;
    
    /**
     * @author zh
     * @ClassName cn.saytime.config.DruidConfiguration
     * @Description
     */
    @Configuration
    @PropertySource(value = "classpath:druid.properties")
    public class DruidConfiguration {
    
    	@Bean(destroyMethod = "close", initMethod = "init")
    	@ConfigurationProperties(prefix = "spring.datasource")
    	public DataSource druidDataSource() {
    		return new DruidDataSource();
    	}
    
    //
    //	/**
    //	 * 注册一个StatViewServlet
    //	 *
    //	 * @return
    //	 */
    //	@Bean
    //	public ServletRegistrationBean druidStatViewServlet() {
    //		//org.springframework.boot.context.embedded.ServletRegistrationBean提供类的进行注册.
    //		ServletRegistrationBean servletRegistrationBean = new ServletRegistrationBean(new StatViewServlet(), "/druid/*");
    //
    //		//添加初始化参数：initParams
    //		//白名单：
    //		servletRegistrationBean.addInitParameter("allow", "127.0.0.1");
    //		//IP黑名单 (存在共同时，deny优先于allow) : 如果满足deny的话提示:Sorry, you are not permitted to view this page.
    		servletRegistrationBean.addInitParameter("deny", "192.168.1.73");
    //		//登录查看信息的账号密码.
    //		servletRegistrationBean.addInitParameter("loginUsername", "admin");
    //		servletRegistrationBean.addInitParameter("loginPassword", "123456");
    //		//是否能够重置数据.
    //		servletRegistrationBean.addInitParameter("resetEnable", "false");
    //		return servletRegistrationBean;
    //	}
    //
    //	/**
    //	 * 注册一个：filterRegistrationBean
    //	 *
    //	 * @return
    //	 */
    //	@Bean
    //	public FilterRegistrationBean druidStatFilter() {
    //
    //		FilterRegistrationBean filterRegistrationBean = new FilterRegistrationBean(new WebStatFilter());
    //
    //		//添加过滤规则.
    //		filterRegistrationBean.addUrlPatterns("/*");
    //
    //		//添加不需要忽略的格式信息.
    //		filterRegistrationBean.addInitParameter("exclusions", "*.js,*.gif,*.jpg,*.png,*.css,*.ico,/druid/*");
    //		return filterRegistrationBean;
    //	}
    }

MybatisConfiguration.java

> 注意这里的MapperScan，换成你项目mapper文件夹路径

package cn.saytime.config;
    
    import com.baomidou.mybatisplus.plugins.PaginationInterceptor;
    import org.mybatis.spring.annotation.MapperScan;
    import org.springframework.context.annotation.Bean;
    import org.springframework.context.annotation.Configuration;
    
    /**
     * @author zh
     * @ClassName cn.saytime.config.MybatisConfiguration
     * @Description
     */
    @Configuration
    @MapperScan("cn.saytime.mapper*")
    public class MybatisConfiguration {
    
    	/*
        * 分页插件，自动识别数据库类型
        * 多租户，请参考官网【插件扩展】
        */
    	@Bean
    	public PaginationInterceptor paginationInterceptor() {
    		return new PaginationInterceptor();
    	}
    
       /*
        * oracle数据库配置JdbcTypeForNull
        * 参考：https://gitee.com/baomidou/mybatisplus-boot-starter/issues/IHS8X
        不需要这样配置了，参考 yml:
        mybatis-plus:
          confuguration
            dbc-type-for-null: 'null'
       @Bean
       public ConfigurationCustomizer configurationCustomizer(){
           return new MybatisPlusCustomizers();
       }
    
       class MybatisPlusCustomizers implements ConfigurationCustomizer {
    
           @Override
           public void customize(org.apache.ibatis.session.Configuration configuration) {
               configuration.setJdbcTypeForNull(JdbcType.NULL);
           }
       }
       */
    
    }

自动生成代码工具类Generator.java

> 换成数据库链接以及输出路径即可。

package cn.saytime.util;
    
    import com.baomidou.mybatisplus.generator.AutoGenerator;
    import com.baomidou.mybatisplus.generator.config.DataSourceConfig;
    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.rules.DbType;
    import com.baomidou.mybatisplus.generator.config.rules.NamingStrategy;
    
    /**
     * @author zh
     * @ClassName cn.aduu.util.Generator
     * @Description
     * @date 2018-02-22 11:37:14
     */
    public class Generator {
    
    	public static void main(String[] args) {
    		String packageName = "cn.saytime";
    		boolean serviceNameStartWithI = false;//auth -> UserService, 设置成true: auth -> IUserService
    		generateByTables(serviceNameStartWithI, packageName, "saytime", "test", "user");
    
    		System.out.println("completed...");
    	}
    
    	/**
    	 * @param serviceNameStartWithI
    	 * @param packageName   包名
    	 * @param author  作者
    	 * @param database  数据库名
    	 * @param tableNames 表名
    	 */
    	private static void generateByTables(boolean serviceNameStartWithI, String packageName, String author, String database, String... tableNames) {
    		GlobalConfig config = new GlobalConfig();
    		String dbUrl = "jdbc:mysql://127.0.0.1:3306/" + database + "?useUnicode=true&characterEncoding=utf8&autoReconnect=true&useSSL=false";
    		DataSourceConfig dataSourceConfig = new DataSourceConfig();
    		dataSourceConfig.setDbType(DbType.MYSQL)
    				.setUrl(dbUrl)
    				.setUsername("root")
    				.setPassword("root")
    				.setDriverName("com.mysql.jdbc.Driver");
    		StrategyConfig strategyConfig = new StrategyConfig();
    		strategyConfig
    				.setCapitalMode(true)
    				.setEntityLombokModel(false)
    				.setDbColumnUnderline(true)
    				.setNaming(NamingStrategy.underline_to_camel)
    //				.setSuperMapperClass("cn.saytime.mapper.BaseMapper")
    				.setInclude(tableNames);//修改替换成你需要的表名，多个表名传数组
    		config.setActiveRecord(false)
    				.setAuthor(author)
    				.setOutputDir("e:\\codeGen")
    				.setFileOverride(true)
    				.setEnableCache(false);
    		if (!serviceNameStartWithI) {
    			config.setServiceName("%sService");
    		}
    		new AutoGenerator().setGlobalConfig(config)
    				.setDataSource(dataSourceConfig)
    				.setStrategy(strategyConfig)
    				.setPackageInfo(
    						new PackageConfig()
    								.setParent(packageName)
    								.setController("web")
    								.setEntity("model")
    								.setMapper("mapper")
    								.setService("service")
    								.setServiceImpl("service.impl")
    								.setXml("mybatis.mappers")
    				).execute();
    	}
    
    }

#### 四、自动生成代码 ####

执行Generator Main方法，到输出路径，可以看到代码文件已经生成好了。

cn
        saytime
            model
                User.java
            mapper
                UserMapper.java
            service
                impl
                    UserServiceImpl.java
                UserService.java
            web
                UserController.java
            mybatis
                mappers
                    UserMapper.xml

将model,mapper,service拷贝到cn.saytime目录下，将mybatis/mappers文件夹拷贝到src/main/resources目录下，这里不演示controller，所以web不拷贝，最终的项目结构图如下：

![这里写图片描述][70]

> 画圈部分是自动生成的代码，具体代码内容这里就不贴出来了。

#### 五、测试 ####

SpringbootMybatisPlusApplicationTests.java

package cn.saytime;
    
    import cn.saytime.model.User;
    import cn.saytime.service.UserService;
    import org.junit.Test;
    import org.junit.runner.RunWith;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.boot.test.context.SpringBootTest;
    import org.springframework.test.context.junit4.SpringRunner;
    
    import java.util.List;
    
    @RunWith(SpringRunner.class)
    @SpringBootTest
    public class SpringbootMybatisPlusApplicationTests {
    
    	@Autowired
    	private UserService userService;
    
    	@Test
    	public void contextLoads() {
    
    		// 所有用户
    		List<User> users = userService.selectList(null);
    		System.out.println(users);
    
    	}
    
    }

输出结果：

[User{, id=1, name=张三}, User{, id=2, name=李四}, User{, id=3, name=王五}]

#### 六、更多使用方式 ####

列举几种常用的增删改查方式，其实最快的方式就是去官网看示例。

1.  查询id=1的用户

User user = userService.selectById(1);

1.  查询name=张三的用户

User user = userService.selectOne(new EntityWrapper<User>().eq("name", "张三"));

1.  查询id>1的用户

List<User> userList = userService.selectList(new EntityWrapper<User>().gt("id", 1));

1.  修改id=1的用户名

User user = userService.selectById(1);
    user.setName("张三2");
    boolean b = userService.updateById(user);

1.  添加用户

User user = new User();
    user.setName("赵六");
    boolean insert = userService.insert(user);

1.  删除用户

boolean b = userService.deleteById(1);

1.  分页查询用户

> 查询id>1 每页一条数据，第二页，也就是第三条数据。

Page<User> userPage = new Page<>();
    userPage.setCurrent(2);
    userPage.setSize(1);
    userService.selectPage(userPage, new EntityWrapper<User>().gt("id", 1));
    List<User> userList = userPage.getRecords();
    System.out.println(userList);

[User{, id=3, name=王五}]

> 基本方法如上，有其他方面的要求可以查询官方文档。

[70]: /images/20220523/fddff19e78744d8a87695ef5759e389b.png