springboot+mybatis通过实体类自动生成数据库表的方法

前言

本章介绍使用mybatis结合mysql数据库自动根据实体类生成相关的数据库表。

首先引入相关的pom包我这里使用的是springboot2.1.8.RELEASE的版本

<dependency>
	<groupId>org.mybatis.spring.boot</groupId>
	<artifactId>mybatis-spring-boot-starter</artifactId>
	<version>2.1.0</version>
</dependency>
<dependency>
	<groupId>com.gitee.sunchenbin.mybatis.actable</groupId>
	<artifactId>mybatis-enhance-actable</artifactId>
	<version>1.0.1</version>
</dependency>
<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>1.1.10</version>
</dependency>

<!--以下两个类需要加入，否则报错无法注入-->
<dependency>
	<groupId>org.apache.commons</groupId>
	<artifactId>commons-lang3</artifactId>
	<version>3.4</version>
</dependency>
<dependency>
	<groupId>net.sf.json-lib</groupId>
	<artifactId>json-lib</artifactId>
	<version>2.4</version>
	<classifier>jdk15</classifier>
	<exclusions>
		<exclusion>
			<artifactId>commons-logging</artifactId>
			<groupId>commons-logging</groupId>
		</exclusion>
	</exclusions>
</dependency>

添加数据库配置文件application.properties
application.properties这里是单独配置mybatis自动建表的相关信息。

mybatis.table.auto=update
mybatis.model.pack=com.xxx.xxx.entity//实体类的路径
mybatis.database.type=mysql

mybatis.table.auto=

create：
每次加载hibernate会自动创建表，以后启动会覆盖之前的表，所以这个值基本不用，严重会导致的数据的丢失。

create-drop ：
每次加载hibernate时根据model类生成表，但是sessionFactory一关闭，表就自动删除，下一次启动会重新创建。

update：
加载hibernate时根据实体类model创建数据库表，这是表名的依据是@Entity注解的值或者@Table注解的值，sessionFactory关闭表不会删除，且下一次启动会根据实体。

model：
更新结构或者有新的实体类会创建新的表。

validate：
启动时验证表的结构，不会创建表 none：启动时不做任何操作

mybatis.model.pack=com.xxx.xxx.entity//你实体类的路径

个人项目配置文件，非统一，根据项目需求配置

进行生成数据库表相关配置

TestConfig配置文件

import com.alibaba.druid.pool.DruidDataSource;
import org.mybatis.spring.SqlSessionFactoryBean;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.beans.factory.config.PropertiesFactoryBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
import org.springframework.jdbc.datasource.DataSourceTransactionManager;

@Configuration
@ComponentScan(basePackages = {"com.gitee.sunchenbin.mybatis.actable.manager.*"})//固定的包
public class TestConfig {
	//连接数据库配置文件的地址，具体查阅配置文件的结构
 @Value("${spring.datasource.druid.driver-class-name}")
 private String driver;
	//连接数据库配置文件的地址，具体查阅配置文件的结构
 @Value("${spring.datasource.druid.url}")
 private String url;
	//连接数据库配置文件的地址，具体查阅配置文件的结构
 @Value("${spring.datasource.druid.username}")
 private String username;
	//连接数据库配置文件的地址，具体查阅配置文件的结构
 @Value("${spring.datasource.druid.password}")
 private String password;

 @Bean
 public PropertiesFactoryBean configProperties() throws Exception{
 PropertiesFactoryBean propertiesFactoryBean = new PropertiesFactoryBean();
 PathMatchingResourcePatternResolver resolver = new PathMatchingResourcePatternResolver();
 propertiesFactoryBean.setLocations(resolver.getResources("classpath*:application.properties"));//classpath*:application.properties是mybatis的生成表配置文件
 return propertiesFactoryBean;
 }

 @Bean
 public DruidDataSource dataSource() {
 DruidDataSource dataSource = new DruidDataSource();
 dataSource.setDriverClassName(driver);
 dataSource.setUrl(url);
 dataSource.setUsername(username);
 dataSource.setPassword(password);
 dataSource.setMaxActive(30);
 dataSource.setInitialSize(10);
 dataSource.setValidationQuery("SELECT 1");
 dataSource.setTestOnBorrow(true);
 return dataSource;
 }

 @Bean
 public DataSourceTransactionManager dataSourceTransactionManager() {
 DataSourceTransactionManager dataSourceTransactionManager = new DataSourceTransactionManager();
 dataSourceTransactionManager.setDataSource(dataSource());
 return dataSourceTransactionManager;
 }

 @Bean
 public SqlSessionFactoryBean sqlSessionFactory() throws Exception{
 SqlSessionFactoryBean sqlSessionFactoryBean = new SqlSessionFactoryBean();
 sqlSessionFactoryBean.setDataSource(dataSource());
 PathMatchingResourcePatternResolver resolver = new PathMatchingResourcePatternResolver();
 sqlSessionFactoryBean.setMapperLocations(resolver.getResources("classpath*:com/gitee/sunchenbin/mybatis/actable/mapping/*/*.xml"));
 sqlSessionFactoryBean.setTypeAliasesPackage("com.xxx.xxx.entity.*");
 //上述classpath*:com/gitee/sunchenbin/mybatis/actable/mapping/*/*.xml固定的包路径
 //com.xxx.xxx.entity.*替换成你的实体类地址
 return sqlSessionFactoryBean;
 }
}

MyBatisMapperScannerConfig配置文件

import org.mybatis.spring.mapper.MapperScannerConfigurer;
import org.springframework.boot.autoconfigure.AutoConfigureAfter;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
@AutoConfigureAfter(TestConfig.class)//上面第一点配置文件类
public class MyBatisMapperScannerConfig {

 @Bean
 public MapperScannerConfigurer mapperScannerConfigurer() throws Exception{
  MapperScannerConfigurer mapperScannerConfigurer = new MapperScannerConfigurer();
   mapperScannerConfigurer.setBasePackage("com.xxx.xxx.mapper.*;com.gitee.sunchenbin.mybatis.actable.dao.*");
  mapperScannerConfigurer.setSqlSessionFactoryBeanName("sqlSessionFactory");
  //com.xxx.xxx.mapper.*替换成你的mapper地址
  //com.gitee.sunchenbin.mybatis.actable.dao.*固定的包
  return mapperScannerConfigurer;
 }

}

新建实体进行测试

注：@Table(name = “”)及@Column（name = “id”）注解使用，实体类继承BaseModel。

import com.gitee.sunchenbin.mybatis.actable.annotation.Column;
import com.gitee.sunchenbin.mybatis.actable.annotation.Table;
import com.gitee.sunchenbin.mybatis.actable.command.BaseModel;
import com.gitee.sunchenbin.mybatis.actable.constants.MySqlTypeConstant;

@Table(name = "em_t")//新建表数据库表名
public class EmpAttr extends BaseModel{
 private static final long serialVersionUID = 5199244153134426433L;

 @Column(name = "id",type = MySqlTypeConstant.INT,length = 11,isKey = true,isAutoIncrement = true)
 private String id;

 @Column(name="ename",type= MySqlTypeConstant.VARCHAR)
 private String ename;

 @Column(name="sal",type= MySqlTypeConstant.VARCHAR)
 private String sal;

 @Column(name="job",type= MySqlTypeConstant.VARCHAR)
 private String job;

 //...省略get，set方法
}

运行项目

会控制台会显示说新建表完成
2020-07-08 11:02:13.895 INFO 48536 — [ main] s.m.a.m.s.SysMysqlCreateTableManagerImpl : 开始创建表：em_t
2020-07-08 11:02:13.983 INFO 48536 — [ main] s.m.a.m.s.SysMysqlCreateTableManagerImpl : 完成创建表：em_t

 . ____   _   __ _ _
 /\\ / ___'_ __ _ _(_)_ __ __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
 \\/ ___)| |_)| | | | | || (_| | ) ) ) )
 ' |____| .__|_| |_|_| |_\__, | / / / /
 =========|_|==============|___/=/_/_/_/
 :: Spring Boot ::  (v2.1.8.RELEASE)

2020-07-08 11:02:11.264 INFO 48536 --- [   main] com.qiaoyuantest.www.WwwApplication  : Starting WwwApplication on DD-HP with PID 48536 (E:\mysoft\kaifasoft\kaifa_code\idea\myiperf_springboot\target\classes started by DD in E:\mysoft\kaifasoft\kaifa_code\idea\myiperf_springboot)
2020-07-08 11:02:11.266 INFO 48536 --- [   main] com.qiaoyuantest.www.WwwApplication  : The following profiles are active: prod
2020-07-08 11:02:12.207 INFO 48536 --- [   main] .s.d.r.c.RepositoryConfigurationDelegate : Multiple Spring Data modules found, entering strict repository configuration mode!
2020-07-08 11:02:12.208 INFO 48536 --- [   main] .s.d.r.c.RepositoryConfigurationDelegate : Bootstrapping Spring Data repositories in DEFAULT mode.
2020-07-08 11:02:12.228 INFO 48536 --- [   main] .s.d.r.c.RepositoryConfigurationDelegate : Finished Spring Data repository scanning in 10ms. Found 0 repository interfaces.
2020-07-08 11:02:12.301 INFO 48536 --- [   main] o.s.c.a.ConfigurationClassPostProcessor : Cannot enhance @Configuration bean definition 'myBatisMapperScannerConfig' since its singleton instance has been created too early. The typical cause is a non-static @Bean method with a BeanDefinitionRegistryPostProcessor return type: Consider declaring such methods as 'static'.
2020-07-08 11:02:12.522 INFO 48536 --- [   main] trationDelegate$BeanPostProcessorChecker : Bean 'org.springframework.transaction.annotation.ProxyTransactionManagementConfiguration' of type [org.springframework.transaction.annotation.ProxyTransactionManagementConfiguration$$EnhancerBySpringCGLIB$$54b62352] is not eligible for getting processed by all BeanPostProcessors (for example: not eligible for auto-proxying)
2020-07-08 11:02:12.613 INFO 48536 --- [   main] trationDelegate$BeanPostProcessorChecker : Bean 'redisConfiguration' of type [com.qiaoyuantest.www.config.RedisConfiguration$$EnhancerBySpringCGLIB$$9518fca7] is not eligible for getting processed by all BeanPostProcessors (for example: not eligible for auto-proxying)
2020-07-08 11:02:12.651 ERROR 48536 --- [   main] o.a.catalina.core.AprLifecycleListener : An incompatible version [1.2.7] of the APR based Apache Tomcat Native library is installed, while Tomcat requires version [1.2.14]
2020-07-08 11:02:12.808 ERROR 48536 --- [   main] o.a.catalina.core.AprLifecycleListener : An incompatible version [1.2.7] of the APR based Apache Tomcat Native library is installed, while Tomcat requires version [1.2.14]
2020-07-08 11:02:12.927 INFO 48536 --- [   main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat initialized with port(s): 8910 (http)
2020-07-08 11:02:12.937 ERROR 48536 --- [   main] o.a.catalina.core.AprLifecycleListener : An incompatible version [1.2.7] of the APR based Apache Tomcat Native library is installed, while Tomcat requires version [1.2.14]
2020-07-08 11:02:12.937 INFO 48536 --- [   main] o.a.coyote.http11.Http11NioProtocol  : Initializing ProtocolHandler ["http-nio-8910"]
2020-07-08 11:02:12.944 INFO 48536 --- [   main] o.apache.catalina.core.StandardService : Starting service [Tomcat]
2020-07-08 11:02:12.944 INFO 48536 --- [   main] org.apache.catalina.core.StandardEngine : Starting Servlet engine: [Apache Tomcat/9.0.24]
2020-07-08 11:02:13.035 INFO 48536 --- [   main] o.a.c.c.C.[Tomcat].[localhost].[/]  : Initializing Spring embedded WebApplicationContext
2020-07-08 11:02:13.036 INFO 48536 --- [   main] o.s.web.context.ContextLoader   : Root WebApplicationContext: initialization completed in 1732 ms
2020-07-08 11:02:13.623 INFO 48536 --- [   main] o.s.s.concurrent.ThreadPoolTaskExecutor : Initializing ExecutorService 'applicationTaskExecutor'
2020-07-08 11:02:13.676 INFO 48536 --- [   main] c.g.s.m.a.m.handler.StartUpHandlerImpl : databaseType=mysql，开始执行mysql的处理方法
Loading class `com.mysql.jdbc.Driver'. This is deprecated. The new driver class is `com.mysql.cj.jdbc.Driver'. The driver is automatically registered via the SPI and manual loading of the driver class is generally unnecessary.
2020-07-08 11:02:13.829 INFO 48536 --- [   main] com.alibaba.druid.pool.DruidDataSource : {dataSource-1} inited
file类型的扫描
2020-07-08 11:02:13.895 INFO 48536 --- [   main] s.m.a.m.s.SysMysqlCreateTableManagerImpl : 开始创建表：em_t
2020-07-08 11:02:13.983 INFO 48536 --- [   main] s.m.a.m.s.SysMysqlCreateTableManagerImpl : 完成创建表：em_t
2020-07-08 11:02:14.002 INFO 48536 --- [   main] c.q.www.config.RedisConfiguration  : 自定义RedisCacheManager加载完成
2020-07-08 11:02:14.826 INFO 48536 --- [   main] o.a.coyote.http11.Http11NioProtocol  : Starting ProtocolHandler ["http-nio-8910"]
2020-07-08 11:02:14.849 INFO 48536 --- [   main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat started on port(s): 8910 (http) with context path ''
2020-07-08 11:02:14.851 INFO 48536 --- [   main] com.qiaoyuantest.www.WwwApplication  : Started WwwApplication in 4.162 seconds (JVM running for 4.863)

此时查看一下数据库表会发现新建有em_t表

新建表就这样完成。

如出现
Error creating bean with name ‘startUpHandlerImpl': Invocation of init method failed; nested exception is java.lang.NoClassDefFoundError: org/apache/commons/lang/ArrayUtils错误

说明pom缺省包或者包不正确

<!--以下两个类需要加入，否则报错无法注入-->
	<dependency>
		<groupId>org.apache.commons</groupId>
		<artifactId>commons-lang3</artifactId>
		<version>3.4</version>
	</dependency>
	<dependency>
		<groupId>net.sf.json-lib</groupId>
		<artifactId>json-lib</artifactId>
		<version>2.4</version>
		<classifier>jdk15</classifier>
		<exclusions>
			<exclusion>
				<artifactId>commons-logging</artifactId>
				<groupId>commons-logging</groupId>
			</exclusion>
		</exclusions>
	</dependency>

如需要项目源码或者对代码有疑问的评论留言，下期会动手实现mybatis plus内嵌的CRUD自动增删改查

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