SpringBoot（十二）：SpringBoot整合Mybatis-Plus

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：

<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.demo</groupId>
  <artifactId>spriingboot_mybatis_plus</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.5.10.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>
        <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>

        <!-- druid数据库连接池 -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>${druid.version}</version>
        </dependency>

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

        <!-- Mybatis-plus -->
        <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。

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:

spring:
  datasource:
    driver-class-name: com.mysql.jdbc.Driver
    url: jdbc:mysql://192.168.1.20:3306/test
    username: root
    password: root123

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.demo.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'
    
logging.level.com.demo.mapper: debug

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.demo.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;

/**
 * @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.demo.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.demo.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.demo.utils;
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;

//根据表名自动生成java文件
public class Generator {

    public static void main(String[] args) {
        String packageName = "cn.demo";
        boolean serviceNameStartWithI = false;
        generateByTables(serviceNameStartWithI, packageName, "li", "test", "user");//li作者。test数据库名。user表名。
        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://192.168.1.20:3306/" + database + "?useUnicode=true&characterEncoding=utf8&autoReconnect=true&useSSL=false";
        DataSourceConfig dataSourceConfig = new DataSourceConfig();
        dataSourceConfig.setDbType(DbType.MYSQL)
                .setUrl(dbUrl)
                .setUsername("root")
                .setPassword("root123")
                .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")//生成的java到文件夹下
                .setFileOverride(true)
                .setEnableCache(false);
        if (!serviceNameStartWithI) {
            config.setServiceName("%sService");
        }
        new AutoGenerator().setGlobalConfig(config)
                .setDataSource(dataSourceConfig)
                .setStrategy(strategyConfig)
                .setPackageInfo(
                        new PackageConfig()
                                .setParent(packageName)
                                .setController("web")//生成的代码到文件夹下cn.demo.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:

 将model,mapper,service拷贝到cn.demo目录下，将mybatis/mappers文件夹拷贝到src/main/resources目录下.

五、测试

SpringbootMybatisPlusApplicationTests.java

package cn.demo;
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 cn.demo.model.User;
import cn.demo.service.UserService;

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);
        
        //查询id=1的用户
        User user = userService.selectById(1);
        System.out.println("users1=="+user);
    }

}

输出结果：

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。

查询id=1的用户
User user = userService.selectById(1);

查询name=张三的用户
User user = userService.selectOne(new EntityWrapper<User>().eq("name", "张三"));

查询id>1的用户
List<User> userList = userService.selectList(new EntityWrapper<User>().gt("id", 1));
修改id=1的用户名
User user = userService.selectById(1);
user.setName("张三2");
boolean b = userService.updateById(user);

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

删除用户
boolean b = userService.deleteById(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}]