SchemaExport 类使用（自动生成数据表）

川长思鸟来 2022-06-07 11:29 216阅读 0赞

**SchemaExport类使用（自动生成数据表）**  
使用它自动生成数据表  
1、功能类似于在主配置文件中ddl.auto功能  
2、不同版本的使用不同  
  
  
**下面将讲解hibernate5和hibernate4的使用方式（使用的工具为eclipse）。  
  
  
一、hibernate5中SchemaExport类的使用**

创建一个java项目，项目结构如下：

![Center][]

lib目录下则是hibernate5需要的jar包（注需要将jar加载到项目中：选中jar包右键 --》BuildPath--》Add to Build Path）  
  
log4j.properties为日志配置文件（需要加载配置junit），此项目可以不需要日志，使用日志只是为了观察方便。  
  
示例代码：  
1、主配置文件 hibernate.cfg.xml

<?xml version="1.0" encoding="UTF-8"?>
    
    <!DOCTYPE hibernate-configuration PUBLIC
    	"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
    	"http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
    
    <hibernate-configuration>
    	<session-factory>
    		
    		<property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
    		<property name="hibernate.connection.url">jdbc:mysql://localhost:3306/db?characterEncoding=utf8</property>
    		<property name="hibernate.connection.username">root</property>
    		<property name="hibernate.connection.password"></property>
    
    		
    		
    		<property name="hibernate.dialect">org.hibernate.dialect.MySQL5Dialect</property>
    		
    		
    		<property name="show_sql">true</property>
    		<property name="format_sql">true</property>
    		
    		<mapping resource="cn/sz/entity/User.hbm.xml" />
    	</session-factory>
    </hibernate-configuration>

2、实体类 User.java

package cn.sz.entity;
    
    import java.io.Serializable;
    
    public class User implements Serializable {
    	private Integer uid;
    	private String uname;
    
    	public Integer getUid() {
    		return uid;
    	}
    
    	public void setUid(Integer uid) {
    		this.uid = uid;
    	}
    
    	public String getUname() {
    		return uname;
    	}
    
    	public void setUname(String uname) {
    		this.uname = uname;
    	}
    
    }

3、映射文件 User.hbm.xml

<?xml version="1.0" encoding="UTF-8"?>
    <!DOCTYPE hibernate-mapping PUBLIC
    	"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
    	"http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
    
    <hibernate-mapping package="cn.sz.entity">
    	
    	<class table="user" name="User">
    		
    		<id name="uid">
    			
    			<generator class="native"></generator>
    		</id>
    		
    		<property name="uname"></property>
    	</class>
    </hibernate-mapping>

4、log4j.properties

log4j.rootLogger=DEBUG,console,FILE
    log4j.appender.console=org.apache.log4j.ConsoleAppender
    log4j.appender.console.threshold=INFO
    log4j.appender.console.layout=org.apache.log4j.PatternLayout
    log4j.appender.console.layout.ConversionPattern=%d{yyyy-MM-dd HH:mm:ss} [%5p] - %c -%F(%L) -%m%n
    log4j.appender.FILE=org.apache.log4j.RollingFileAppender
    log4j.appender.FILE.maxBackupIndex=100
    ##log4j.appender.FILE=org.apache.log4j.DailyRollingFileAppender 
    log4j.appender.FILE.Append=true
    log4j.appender.FILE.File=c:/error1.log
    log4j.appender.FILE.Threshold=INFO
    log4j.appender.FILE.layout=org.apache.log4j.PatternLayout
    log4j.appender.FILE.layout.ConversionPattern=%d{yyyy-MM-dd HH:mm:ss} [%5p] - %c -%F(%L) -%m%n
    log4j.appender.FILE.MaxFileSize=1MB

5、测试类 SchemaExportTest.java

package cn.sz.test;
    
    import java.util.EnumSet;
    
    import org.hibernate.boot.Metadata;
    import org.hibernate.boot.MetadataSources;
    import org.hibernate.boot.registry.StandardServiceRegistry;
    import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
    import org.hibernate.cfg.Configuration;
    import org.hibernate.tool.hbm2ddl.SchemaExport;
    import org.hibernate.tool.schema.TargetType;
    
    public class SchemaExportTest {
    	public static void main(String[] args) {
    		Configuration cfg = new Configuration();
    		StandardServiceRegistry serviceRegistry = new StandardServiceRegistryBuilder().configure().build();
    		Metadata metadata = new MetadataSources(serviceRegistry).buildMetadata();
    		SchemaExport schemaExport = new SchemaExport();
    		schemaExport.create(EnumSet.of(TargetType.DATABASE), metadata);
    	}
    
    }

运行测试类，可以在数据库中发现增加了数据表user  
  
![Center 1][]  
  
**二、hibernate4中SchemaExport类的使用**

创建一个java项目，项目结构如下：

![Center 2][]

<?xml version="1.0" encoding="UTF-8"?>
    <!DOCTYPE hibernate-configuration PUBLIC
    	"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
    	"http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
    
    <hibernate-configuration>
    	<session-factory>
    		
    		<property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
    		<property name="hibernate.connection.url">jdbc:mysql://localhost:3306/db?characterEncoding=utf8</property>
    		<property name="hibernate.connection.username">root</property>
    		<property name="hibernate.connection.password"></property>
    		
    		<property name="hibernate.dialect">org.hibernate.dialect.MySQL5Dialect</property>
    		
    		<property name="show_sql">true</property>
    		<property name="format_sql">true</property>
    		
    		<mapping resource="cn/sz/entity/Person.hbm.xml" />
    	</session-factory>
    </hibernate-configuration>

2、实体类Person.java

package cn.sz.entity;
    
    import java.io.Serializable;
    
    public class Person implements Serializable {
    	private Integer pid;
    	private String pname;
    
    	public Integer getPid() {
    		return pid;
    	}
    
    	public void setPid(Integer pid) {
    		this.pid = pid;
    	}
    
    	public String getPname() {
    		return pname;
    	}
    
    	public void setPname(String pname) {
    		this.pname = pname;
    	}
    
    }

3、映射文件 Person.hbm.xml

<?xml version="1.0" encoding="UTF-8"?>
    <!DOCTYPE hibernate-mapping PUBLIC
    	"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
    	"http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
    
    <hibernate-mapping package="cn.sz.entity">
    	
    	<class table="person" name="Person">
    		
    		<id name="pid">
    			
    			<generator class="native"></generator>
    		</id>
    		
    		<property name="pname"></property>
    	</class>
    </hibernate-mapping>

4、log4j.properties

5、测试类 SchemaExportTest.java

package cn.sz.test;
    
    import org.hibernate.cfg.Configuration;
    import org.hibernate.tool.hbm2ddl.SchemaExport;
    
    public class SchemaExportTest {
    
    	public static void main(String[] args) {
    		// TODO Auto-generated method stub
    		Configuration config = new Configuration().configure();
    		SchemaExport schemaExport=new SchemaExport(config);
    		schemaExport.create(true, true);
    	}
    
    }

运行测试类，可以在数据库中发现增加了数据表person  
![Center 3][]  
注：junit配置可以参考 [http://blog.csdn.net/benxiaohai888/article/details/78231911][http_blog.csdn.net_benxiaohai888_article_details_78231911]

[Center]: /images/20220607/6d373d0f97724ce884380420ec95412a.png
[Center 1]: /images/20220607/d03889082b4e47958b6a4f3435e6c438.png
[Center 2]: /images/20220607/ab309333b9644d2484210b2d382fad8a.png
[Center 3]: /images/20220607/8f8264275a6b4fb19bd1b3f8b30a1a60.png
[http_blog.csdn.net_benxiaohai888_article_details_78231911]: http://blog.csdn.net/benxiaohai888/article/details/78231911