Hibernate java.lang.OutOfMemoryError：Java堆空间 [英] Hibernate java.lang.OutOfMemoryError: Java heap space

问题描述

我有一个运行在Tomcat 7上的Java Web应用程序 - jdk1.7

这个应用程序使用Spring 4.1.5.RELEASE和Hibernate 4.2.2.Final

p>

我的问题是构建部分工厂的Heap空间的OutOfMemoryException

这是我的静态方法，它打开SessionFactory

  public class GenericDAO {
 
 public static SessionFactory sessionFactory = null; 
 public static ServiceRegistry serviceRegistry = null; 
 
交易tx = null; 
 
 public static SessionFactory createSessionFactory（）{
 Configuration configuration = new Configuration（）; 
 configuration.configure（）; 
 serviceRegistry = new ServiceRegistryBuilder（）。applySettings（
 configuration.getProperties（））。 buildServiceRegistry（）; 
 sessionFactory = configuration.buildSessionFactory（serviceRegistry）; 
 return sessionFactory; 
 
 
 
 
 $ b $这些是DAO的例子
 
 
 $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $' （）; 
尝试{
 tx = session.beginTransaction（）; 
 session.save（item）; 
 tx.commit（）; 
 return item.getId（）; 
} catch（HibernateException e）{
 if（tx！= null）tx.rollback（）; 
 e.printStackTrace（）; 
} finally {
 session.close（）; 
} 
返回-1; 
 
 
 $ / code $ / pre 
 
 
错误发生在包含
 
 
 
  sessionFactory = configuration.buildSessionFactory（serviceRegistry）;   
 
 
部署，但在使用2到3天后 
 
 
这是我的Hibernate.cfg.xml  
 
 
 <！DOCTYPE hibernate-configuration PUBLIC 
 -  // Hibernate / Hibernate Configuration DTD // EN
http://www.hibernate.org/dtd/冬眠配置-3.0.dtd> 
< hibernate-configuration> 
< session-factory> 
< property name =connection.url> jdbc：sqlserver：//192.168.XX.XXX：1433; databaseName = DatabaseName< / property> 
< property name =connection.driver_class> com.microsoft.sqlserver.jdbc.SQLServerDriver< / property> 
< property name =connection.username>用户名< / property> 
< property name =connection.password>密码< / property> 
< mapping class =it.company.client.project.hibernate.MyObject/> 
 
 <！ - 如果需要，数据库模式将被更新 - > 
<！ - < property name =hbm2ddl.auto>更新< / property> - > 
< / session-factory> 
< / hibernate-configuration> 
  
 
 
解决方案
您必须创建会话工厂一次是一个沉重的重量物体，请参阅 
 
 
以下是文档中关于如何创建应用程序的示例代码：
  import org.hibernate.SessionFactory; 
 import org.hibernate.boot.registry.StandardServiceRegistryBuilder; 
导入org.hibernate.cfg.Configuration; 
 
 public class HibernateUtil {
 
 private static final SessionFactory sessionFactory = buildSessionFactory（）; 
 
 private static SessionFactory buildSessionFactory（）{
 try {
 //从hibernate.cfg.xml创建SessionFactory 
返回新的Configuration（）.configure（）。 buildSessionFactory（
 new StandardServiceRegistryBuilder（）。build（））; 
} 
 catch（Throwable ex）{
 //确保您记录异常，因为它可能被吞噬
 System.err.println（初始化SessionFactory创建失败。 + ex）; 
抛出新的ExceptionInInitializerError（ex）; 
 
 
 
 public static SessionFactory getSessionFactory（）{
 return sessionFactory; 
} 
 
} 
  
 
I have a Java web application running on Tomcat 7 - jdk1.7


This application uses Spring 4.1.5.RELEASE and Hibernate 4.2.2.Final

My problem is a OutOfMemoryException of the Heap space on building section factory

This is my static method that opens a SessionFactory
public class GenericDAO {

    public static SessionFactory sessionFactory = null;
    public static ServiceRegistry serviceRegistry = null;

    Transaction tx = null;

    public static SessionFactory createSessionFactory() {
        Configuration configuration = new Configuration();
        configuration.configure();
        serviceRegistry = new ServiceRegistryBuilder().applySettings(
            configuration.getProperties()). buildServiceRegistry();
        sessionFactory = configuration.buildSessionFactory(serviceRegistry);
        return sessionFactory;
    }
}
And this is an example of DAO
public class SpecificDAO extends GenericDAO {
    public int save(MyObject item) {
        Session session = createSessionFactory().openSession();
        try {
            tx = session.beginTransaction();
            session.save(item);
            tx.commit();
            return item.getId();
        } catch (HibernateException e) {
            if (tx != null) tx.rollback();
                 e.printStackTrace();
        } finally {
            session.close();
        }
        return -1;
    }
}
The error occurs at the line containing 

sessionFactory = configuration.buildSessionFactory(serviceRegistry);

The problem doesn't occur immediately at the deploy, but after 2 o 3 days of usage

This is my Hibernate.cfg.xml
<!DOCTYPE hibernate-configuration PUBLIC
    "-//Hibernate/Hibernate Configuration DTD//EN"
    "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
 <hibernate-configuration>
<session-factory>
    <property name="connection.url">jdbc:sqlserver://192.168.XX.XXX:1433;databaseName=DatabaseName</property>
    <property name="connection.driver_class">com.microsoft.sqlserver.jdbc.SQLServerDriver</property>
    <property name="connection.username">username</property>
    <property name="connection.password">password</property>
    <mapping class="it.company.client.project.hibernate.MyObject"/>

    <!-- DB schema will be updated if needed -->
    <!-- <property name="hbm2ddl.auto">update</property> -->
</session-factory>
</hibernate-configuration>

解决方案
You have to create the session factory only once as it is a heavy weight object, refer to the hibernate documentation for its details.

Here is the sample code from the doc on how it should be created:
import org.hibernate.SessionFactory;
import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
import org.hibernate.cfg.Configuration;

public class HibernateUtil {

    private static final SessionFactory sessionFactory = buildSessionFactory();

    private static SessionFactory buildSessionFactory() {
        try {
            // Create the SessionFactory from hibernate.cfg.xml
            return new Configuration().configure().buildSessionFactory(
                new StandardServiceRegistryBuilder().build() );
        }
        catch (Throwable ex) {
            // Make sure you log the exception, as it might be swallowed
            System.err.println("Initial SessionFactory creation failed." + ex);
            throw new ExceptionInInitializerError(ex);
        }
    }

    public static SessionFactory getSessionFactory() {
        return sessionFactory;
    }

}


                        
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