How to fix java.lang.NoClassDefFoundError: net/sf/ehcache/CacheException when configuring EhCache for Hibernate 5.2.5

Question

I am new to Hibernate and I started learning caching in Hibernate, I want to configure EhCache in my hibernate configuration file. I have added hibernate-ehcache-5.2.5.Final.jar to my build path and here is 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>

    <!-- Database connection settings -->
    <property name="connection.driver_class">com.mysql.jdbc.Driver</property>
    <property name="connection.url">jdbc:mysql://localhost:3306/test</property>
    <property name="connection.username">root</property>
    <property name="connection.password"></property>

    <!-- JDBC connection pool -->
    <property name="connection.pool_size">1</property>

    <!-- SQL dialect -->
    <property name="dialect">org.hibernate.dialect.MySQLDialect</property>

    <!-- Enable the second level cache -->
    <property name="hibernate.cache.use_second_level_cache">true</property> 
    <property name="hibernate.cache.region.factory_class">org.hibernate.cache.ehcache.EhCacheRegionFactory</property>

    <!-- Echo all executed SQL to stdout -->
    <property name="show_sql">true</property>

    <!-- Drop and recrete the database schema on startup -->
    <property name="hbm2ddl.auto">update</property>

</session-factory>

</hibernate-configuration>

Here is the main class from where I configure the session factory:

package hibernate;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;

public class Main { 
    public static void main(String[] args) {
        SessionFactory sessionFactory = new Configuration().configure().buildSessionFactory();
}

After I run this code I receive the error message:

Exception in thread "main" java.lang.NoClassDefFoundError: net/sf/ehcache/CacheException
at java.lang.Class.getDeclaredConstructors0(Native Method)
at java.lang.Class.privateGetDeclaredConstructors(Unknown Source)
at java.lang.Class.getConstructor0(Unknown Source)
at java.lang.Class.getConstructor(Unknown Source)
at org.hibernate.cache.internal.StrategyCreatorRegionFactoryImpl.create(StrategyCreatorRegionFactoryImpl.java:38)
at org.hibernate.cache.internal.StrategyCreatorRegionFactoryImpl.create(StrategyCreatorRegionFactoryImpl.java:23)
at org.hibernate.boot.registry.selector.internal.StrategySelectorImpl.resolveStrategy(StrategySelectorImpl.java:198)
at org.hibernate.boot.registry.selector.internal.StrategySelectorImpl.resolveStrategy(StrategySelectorImpl.java:161)
at org.hibernate.cache.internal.RegionFactoryInitiator.initiateService(RegionFactoryInitiator.java:67)
at org.hibernate.cache.internal.RegionFactoryInitiator.initiateService(RegionFactoryInitiator.java:28)
at org.hibernate.boot.registry.internal.StandardServiceRegistryImpl.initiateService(StandardServiceRegistryImpl.java:88)
at org.hibernate.service.internal.AbstractServiceRegistryImpl.createService(AbstractServiceRegistryImpl.java:257)
at org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:231)
at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:210)
at org.hibernate.boot.internal.MetadataBuilderImpl$MetadataBuildingOptionsImpl.<init>(MetadataBuilderImpl.java:663)
at org.hibernate.boot.internal.MetadataBuilderImpl.<init>(MetadataBuilderImpl.java:127)
at org.hibernate.boot.MetadataSources.getMetadataBuilder(MetadataSources.java:135)
at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:654)
at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:726)
at hibernate.Main.main(Main.java:31)
Caused by: java.lang.ClassNotFoundException: net.sf.ehcache.CacheException
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
... 20 more

Can you please help me to fix this or tell me what I did wrong? I am using Hibernate 5.2.5, MySQL DBMS and simple java project in Eclipse IDE. As I already stated I have added "hibernate-ehcache-5.2.5.Final.jar" to my build path and this jar contains org.hibernate.cache.ehcache.EhCacheRegionFactory class. I also tried to use some earlier versions of ehcache jar like "hibernate-ehcache-5.0.2.Final.jar" or "ehcache-3.2.0.jar" but I was getting the same error.

Answer 1

You seem to have a class loader issue. Hibernate is probably loaded in a class loader that doesn't see Ehcache. Assuming that the Ehcache jar is indeed in the classpath. Because you need both hibernate-ehcache and ehcache in the classpath.

Answer 2

hibernate-ehcache (5.x) references ehcache-2.x and supposedly does not work correctly with ehcache-3.x.

You may want to use hibernate-jcache as ehcache-3.x is jcache compliant. See this question

Answer 3

Add to the classpath the ehcache.jar and hibernate-ehcache.jar archives that you find in:

hibernate-release-5.2.9.Final\lib\optional\ehcache

Adding the lastest ehcache.jar from www.ehcache.org will not do the trick.