NullPointerException when trying to integrate EHCache

mraible · **Joined:** Sun Oct 05, 2003 9:07 am **Posts:** 47

I'm trying to use integrate EHCache into my application as documented at:

http://www.hibernate.org/158.html

I get a NPE when trying to run my JUnit test. If I remove the <cache> from my mapping file, the test works (but I don't know if caching is working). My ehcache.xml file is as follows:

Code:

<ehcache>
    <cache name="org.appfuse.model.User"
        maxElementsInMemory="1000"
        eternal="false"
        timeToIdleSeconds="300"
        timeToLiveSeconds="600"
        overflowToDisk="true"/> 
</ehcache>

Hibernate version: 2.1.6

Mapping documents:

User.hbm.xml:

Code:

<hibernate-mapping>
    <class name="org.appfuse.model.User" table="app_user">
        <cache usage="read-write"/>
        <id name="id" column="id" unsaved-value="0">
            <generator class="increment"/>
        </id>
        <!-- properties -->
    </class>
</hibernate-mapping>

Code between sessionFactory.openSession() and session.close():

Using Spring - I'm assuming I don't have to configure a caching provider since EHCache is the default. Here are my hibernateProperties of my sessionFactory bean.

Code:

        <property name="hibernateProperties">
            <props>
                <prop key="hibernate.dialect">
                    net.sf.hibernate.dialect.MySQLDialect
                </prop>
                <prop key="hibernate.hbm2ddl.auto">update</prop>
            </props>
        </property>

Full stack trace of any exception that occurs:

Code:

    [junit] INFO - SettingsFactory.buildSettings(129) | cache provider: net.sf.hibernate.cache.EhCacheProvider
    [junit] INFO - Configuration.configureCaches(1116) | instantiating and configuring caches
    [junit] DEBUG - CacheManager.create(178) | Creating new CacheManager with default config
    [junit] DEBUG - CacheManager.configure(152) | Configuring ehcache from classpath.
    [junit] DEBUG - Configurator.configure(120) | Configuring ehcache from ehcache.xml found in the classpath: file:/Users/mraible/workspace/appfuse/web/WEB-INF/classes/ehcache.xml
    [junit] Testsuite: org.appfuse.dao.UserDAOTest
    [junit] Tests run: 3, Failures: 3, Errors: 0, Time elapsed: 0.034 sec

    [junit] Testcase: warning(junit.framework.TestSuite$1):     FAILED
    [junit] Exception in constructor: testGetUsers (org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sessionFactory' defined in file [/Users/mraible/workspace/appfuse/web/WEB-INF/applicationContext-hibernate.xml]: Initialization of bean failed; nested exception is java.lang.NullPointerException: null
    [junit] java.lang.NullPointerException
    [junit]     at net.sf.ehcache.config.Configuration$DefaultCache.access$100(Configuration.java:308)
    [junit]     at net.sf.ehcache.config.Configuration.getDefaultCache(Configuration.java:129)
    [junit]     at net.sf.ehcache.CacheManager.configure(CacheManager.java:159)
    [junit]     at net.sf.ehcache.CacheManager.<init>(CacheManager.java:128)
    [junit]     at net.sf.ehcache.CacheManager.create(CacheManager.java:180)
    [junit]     at net.sf.ehcache.CacheManager.getInstance(CacheManager.java:196)
    [junit]     at net.sf.hibernate.cache.EhCache.<init>(EhCache.java:91)
    [junit]     at net.sf.hibernate.cache.EhCacheProvider.buildCache(EhCacheProvider.java:84)
    [junit]     at net.sf.hibernate.cfg.Configuration.configureCaches(Configuration.java:1130)
    [junit]     at net.sf.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:790)
    [junit]     at org.springframework.orm.hibernate.LocalSessionFactoryBean.newSessionFactory(LocalSessionFactoryBean.java:436)
    [junit]     at org.springframework.orm.hibernate.LocalSessionFactoryBean.afterPropertiesSet(LocalSessionFactoryBean.java:374)
    [junit]     at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:968)
    [junit]     at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:285)
    [junit]     at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:205)
    [junit]     at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199)
    [junit]     at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:136)
    [junit]     at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:218)
    [junit]     at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:279)
    [junit]     at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:81)
    [junit]     at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:66)
    [junit]     at org.appfuse.dao.BaseDAOTestCase.<init>(BaseDAOTestCase.java:20)
    [junit]     at org.appfuse.dao.UserDAOTest.<init>(UserDAOTest.java:8)
    [junit]     at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    [junit]     at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
    [junit]     at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
    [junit]     at java.lang.reflect.Constructor.newInstance(Constructor.java:274)
    [junit]     at junit.framework.TestSuite.createTest(TestSuite.java:131)
    [junit]     at junit.framework.TestSuite.addTestMethod(TestSuite.java:114)
    [junit]     at junit.framework.TestSuite.<init>(TestSuite.java:75)
    [junit]     at org.apache.tools.ant.taskdefs.optional.junit.JUnitTestRunner.<init>(JUnitTestRunner.java:225)
    [junit]     at org.apache.tools.ant.taskdefs.optional.junit.JUnitTestRunner.<init>(JUnitTestRunner.java:177)
    [junit]     at org.apache.tools.ant.taskdefs.optional.junit.JUnitTestRunner.main(JUnitTestRunner.java:519)
    [junit] )

Name and version of the database you are using: MySQL 4.0.16

emmanuel · **Posted:** Mon Aug 16, 2004 6:11 pm

Can you give us the ehcache version you use and build a simple working testcase, I'll look at that.

mraible · **Joined:** Sun Oct 05, 2003 9:07 am **Posts:** 47

I'm using ehcache 0.9 with Spring 1.1 and Hibernate 2.1.6 on OS X. As for building a "simple working testcase" - I'm assuming you want me to trim down my app to a handful of classes and JARs that can be run with Ant? Unfortunately, that might take a while.

Are there guesses you have as to what might be causing the problem?

FYI, I tried this back in May and found that everything worked fine with ehcache.xml wasn't in my classpath.

http://sourceforge.net/forum/message.php?msg_id=2557362

Thanks,

Matt

mraible · **Joined:** Sun Oct 05, 2003 9:07 am **Posts:** 47

I figured it out. From the documentation, it appears that you only have to have a <cache> configured for your class. However, it looks like you have to have <diskStore> and <defaultCache> elements as well.

If I leave out <diskStore>, I get:

Code:

    [junit] DEBUG - MemoryStore.get(193) | org.appfuse.model.UserCache: MemoryStore miss for 47
    [junit] ERROR - DiskStore.get(236) | org.appfuse.model.UserCache: Could not read disk store element for key 47
    [junit] java.lang.Exception: org.appfuse.model.UserCache: The Disk store is not active.
    [junit]     at net.sf.ehcache.store.DiskStore.checkActive(DiskStore.java:178)
    [junit]     at net.sf.ehcache.store.DiskStore.get(DiskStore.java:210)
    [junit]     at net.sf.ehcache.Cache.searchInDiskStore(Cache.java:408)
    [junit]     at net.sf.ehcache.Cache.get(Cache.java:277)

But my tests still pass. If I remove <defaultCache>, that's when the aforementioned exception occurs. If I have them both in there, everything works.

Maybe the documentation needs to be updated?

Thanks,

Matt

emmanuel · **Posted:** Wed Aug 18, 2004 3:48 am

check the ehcache documentation.
Do you want to persist on disk?
If not use overflowToDisk="false"

nheudecker · **Posted:** Thu Aug 19, 2004 4:24 pm

Having just experienced the same error, it would be great if the EHCache docs could be improved to correct this shortcoming.

tpischke · **Posted:** Thu Oct 21, 2004 8:03 pm

I'm getting the exact same exception and stacktrace when trying to enable ehcache on a single class. Things work if I delete ehcache.xml, but they don't work if I delete the contents of ehcache.xml or if I remove all <cache> elements.

ehcache.xml

Code:

<ehcache>
    <cache name="sb.biz.model.Rob"
    maxElementsInMemory="100"
    eternal="true"
    timeToIdleSeconds="0"
    timeToLiveSeconds="0"
    overflowToDisk="false"/>
</ehcache>

Rob.hbm.xml

Code:

<class name="sb.biz.model.Rob" table="rob" mutable="true" polymorphism="implicit" dynamic-update="false" dynamic-insert="false" batch-size="1" select-before-update="false" optimistic-lock="version">
    <meta attribute="class-description" inherit="false">
       @hibernate.class
        table="rob"
    </meta>
    <cache usage="transactional"/>

     (...)
</class>

The Exception:

Code:

ERROR - Building SessionFactory failed.
java.lang.NullPointerException
   at net.sf.ehcache.config.Configuration$DefaultCache.access$100(Configuration.java:308)
   at net.sf.ehcache.config.Configuration.getDefaultCache(Configuration.java:129)
   at net.sf.ehcache.CacheManager.configure(CacheManager.java:159)
   at net.sf.ehcache.CacheManager.<init>(CacheManager.java:128)
   at net.sf.ehcache.CacheManager.create(CacheManager.java:180)
   at net.sf.ehcache.CacheManager.getInstance(CacheManager.java:196)
   at net.sf.ehcache.hibernate.Plugin.<init>(Plugin.java:92)
   at net.sf.ehcache.hibernate.Provider.buildCache(Provider.java:89)
   at net.sf.hibernate.cfg.Configuration.configureCaches(Configuration.java:1130)
   at net.sf.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:790)

citu_adrian · **Posted:** Thu Nov 24, 2005 6:10 am

Hi,

i had the same problem and i solved by adding to the ehcache.xml the line

Code:

after the

Quote:

tag