问题
When trying to initialize hibernate from configuration file, I get NullPointerException .. Root cause is shown as
Caused by: org.apache.commons.logging.LogConfigurationException: org.apache.commons.logging.LogConfigurationException: java.lang.NullPointerException (Caused by java.lang.NullPointerException) (Caused by org.apache.commons.logging.LogConfigurationException: java.lang.NullPointerException (Caused by java.lang.NullPointerException))
at org.apache.commons.logging.impl.LogFactoryImpl.newInstance(LogFactoryImpl.java:543)
I have all the logging related jars and properties files in class path.
My hibernate initialization code is :
private static final SessionFactory sessionFactory;
private static final ThreadLocal<Session> hibernateSession=new ThreadLocal<Session>();
static{
try{
sessionFactory=new Configuration().configure("llhs_hibernate.cfg.xml").buildSessionFactory();
System.out.println("done");
}catch (HibernateException he){
he.printStackTrace();
throw new ExceptionInInitializerError(he);
}catch (Exception e){
e.printStackTrace();
throw new ExceptionInInitializerError(e);
}
Simple java classes does not complain about log related error, for example following java class does not complain ..It properly initializes and writes to logs folder
public class MetadataService implements Serializable {
private static final Logger logger = LogManager.getLogger(MetadataService.class);
private static final long serialVersionUID = 1L;
public MetaData getMetaData(){
logger.info("Info");
try {
//some code here
} catch (Exception e1) {
logger.error("Error");
}
return metaData;
}
Since it works for stand alone Java class and not for class doing hibernate initialization --I am more perplexed ..Any pointer? Detailed trace
java.lang.ExceptionInInitializerError
at com.llhs.persistence.impl.db.hibernate.utils.HibernateUtils.<clinit>(HibernateUtils.java:17)
at com.llhs.persistence.impl.hibernate.HibernateDbImplTest.addStudentDetails(HibernateDbImplTest.java:61)
at com.llhs.persistence.impl.hibernate.HibernateDbImplTest.testAddFindStudentDetails(HibernateDbImplTest.java:128)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:44)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:15)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:41)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:20)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:263)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:69)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:48)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:231)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:60)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:229)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:50)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:222)
at org.junit.runners.ParentRunner.run(ParentRunner.java:292)
at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:49)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)
Caused by: org.apache.commons.logging.LogConfigurationException: org.apache.commons.logging.LogConfigurationException: java.lang.NullPointerException (Caused by java.lang.NullPointerException) (Caused by org.apache.commons.logging.LogConfigurationException: java.lang.NullPointerException(Caused by java.lang.NullPointerException))
at org.apache.commons.logging.impl.LogFactoryImpl.newInstance(LogFactoryImpl.java:543)
at org.apache.commons.logging.impl.LogFactoryImpl.getInstance(LogFactoryImpl.java:235)
at org.apache.commons.logging.impl.LogFactoryImpl.getInstance(LogFactoryImpl.java:209)
at org.apache.commons.logging.LogFactory.getLog(LogFactory.java:351)
at org.hibernate.cfg.Configuration.<clinit>(Configuration.java:126)
... 26 more
Caused by: org.apache.commons.logging.LogConfigurationException: java.lang.NullPointerException (Caused by java.lang.NullPointerException)
at org.apache.commons.logging.impl.LogFactoryImpl.getLogConstructor(LogFactoryImpl.java:397)
at org.apache.commons.logging.impl.LogFactoryImpl.newInstance(LogFactoryImpl.java:529)
... 30 more
Caused by: java.lang.NullPointerException
at org.apache.commons.logging.impl.LogFactoryImpl.getLogConstructor(LogFactoryImpl.java:374)
... 31 more
There is alignment issue while posting trace, sorry abt that, not able to correct that one..
回答1:
Finally, I was able to solve this. As later guessed it turned out to be an eclipse configuration. In eclipse 3.7, code name indigo, the way libs were being added to the classpath caused this issue ..
- First way: Debug Configurations->classpath->bootstarp entries, if Add libs added by selecting "Add Jars" options, THIS DOES NOT Work.
- Correct WAY: Define a classpath variable from window->preferences->java->buildpath->classpath variable, say HIBERNATE_LIBS and point it ti libs folder Now, got to Debug Configurations->classpath->bootstarp entries, select "Advanced option" and add the class path variable. This FIXED the issue.
I guess this is specific to 3.7, as I upgraded the eclipse version and started getting this issue, First way still works in eclipse 3.2
来源：https://stackoverflow.com/questions/7245401/getting-exception-in-initializing-log4j-files