与Ehcache一起使用的java.lang.NullPointerException Hibernate

我将Hibernate 4.1.2与Ehcache 2.4.3一起使用（加载Hibernate时与Hibernate一起提供）

My 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.microsoft.sqlserver.jdbc.SQLServerDriver </property>
          <property name="hibernate.connection.url"> jdbc:sqlserver://localhost:1433;databaseName=Stock_indices</property>
          <property name="hibernate.connection.username">xxx</property>
          <property name="hibernate.connection.password">xxx</property>
          <property name="hibernate.show_sql">true</property>
          <property name="hibernate.dialect">org.hibernate.dialect.SQLServerDialect</property>
          <property name="hibernate.hbm2ddl.auto">update</property>
          <property name="hibernate.c3p0.min_size">5</property>
          <property name="hibernate.c3p0.max_size">20</property>
          <property name="hibernate.c3p0.timeout">300</property>
          <property name="hibernate.c3p0.max_statements">50</property>
          <property name="hibernate.c3p0.idle_test_period">30</property> 


          <property name="hibernate.cache.use_second_level_cache">true</property>
          <property name="hibernate.cache.use_query_cache">true</property>
          <property  name="hibernate.cache.region.factory_class">org.hibernate.cache.ehcache.SingletonEhCacheRegionFactory              </property>
          <property name="net.sf.ehcache.configurationResourceName">ehcache-entity.xml</property>

          <mapping resource="mapping.xml"/>

      </session-factory>
</hibernate-configuration>

}

---

我终于找到了代码不起作用的原因。谢谢Vinodn的建议

config.getDefaultCacheConfiguration().isTerracottaClustered() 

实际上，我没有在我的ehcache-entity.xml中配置defaultCache标记，因此

config.getDefaultCacheConfiguration()

---

返回null。因此，添加defaultCache解决了问题。

将

ehcache entity.xml

放在类路径中，由hibernate配置加载。

没问题。 如果资源名为ehcache.xml并放置在类路径中，则不必显式指定属性“net.sf.ehcache.configurationResourceName”的值。当您有多个缓存管理器时，可以选择此选项

或者，您可以将所有资源文件从lib移动到一个类似WEB-INF/resources的目录中，以便在类路径下更容易地引用它

Ehcache在类路径的顶层查找名为Ehcache.xml的文件。如果失败，它将在类路径中查找ehcache-failsafe.xml。ehcache-failsafe.xml打包在ehcache jar中，应该始终可以找到

---

在ehcache.xml中添加defaultCache配置对我也有帮助。

请发布实际初始化Hibernate配置的代码或配置。@yair:已经编辑了我的问题。假设这是导致空指针的代码。Configuration config=ConfigurationFactory.parseConfiguration（url）；如果（config.getDefaultCacheConfiguration（）。我想在类路径中找不到它。@vinodn:它已添加到与hibernate.cfg.xml相同的文件夹中，请参见我的图片。.您是否尝试了lib/ehcache-entity.xml？我认为应该有更方便用户的异常：）@ctapobep:不确定您的意思：（我的意思是，我不希望抛出NPE，而是希望出现一些IvalidConfigurationException或类似的smthng。

     java.lang.NullPointerException at   org.hibernate.cache.ehcache.internal.util.HibernateUtil.loadAndCorrectConfiguration(HibernateUtil.java:64)
  at  org.hibernate.cache.ehcache.SingletonEhCacheRegionFactory.start(SingletonEhCacheRegionFactory.java:91)
 at org.hibernate.internal.SessionFactoryImpl.<init>(SessionFactoryImpl.java:281)
 at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1741)
          ............

package stockdataservlet;

import java.io.IOException;
import java.math.BigDecimal;
import java.util.Iterator;
import java.util.List;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;
import org.hibernate.service.ServiceRegistry;
import org.hibernate.service.ServiceRegistryBuilder;

import com.google.gson.Gson;
import com.microsoft.sqlserver.jdbc.*;


 public class DataServlet extends HttpServlet {
     private static final long serialVersionUID = 1L;

     public static SessionFactory sessionfactory = null;
     public void init() {
         try {
             Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver"); 
             Configuration conf = new Configuration();
             conf.configure();
             ServiceRegistry serviceRegistry = new ServiceRegistryBuilder().applySettings(conf.getProperties()).buildServiceRegistry();   
             sessionfactory = conf.buildSessionFactory(serviceRegistry);

               }
       catch(Exception e){

        e.printStackTrace();
               }
               }

     protected void doGet(HttpServletRequest request, HttpServletResponse response) {
          Session session = null;
       try{
           session = sessionfactory.openSession();
           Transaction transaction = session.beginTransaction();
           Query query = session.createSQLQuery("SELECT * FROM STOCKINDEX WHERE TICKER = :index ").addScalar("CLOSEPRICE");
           query.setParameter("index", "AAA");
           List list = query.list();
           transaction.commit();
           String json = new Gson().toJson(list);
           /*response.setContentType("application/json");
           response.setCharacterEncoding("UTF-8");
           response.getWriter().write(json);*/
         }
       catch(Exception e){
        e.printStackTrace();

       }
         finally{

        session.close();
       }    
}

config.getDefaultCacheConfiguration().isTerracottaClustered() 

config.getDefaultCacheConfiguration()