JPA binding classes are not found when added at runtime

Question

Hi,
I have my jpa binding classes in a jar file, which acts as a plugin for my application. I add this jar at runtime using a custom URL class loader. But I am getting exception that my tables are not mapped, when i try to use them.
Here is the exception :-
java.lang.IllegalArgumentException: org.hibernate.hql.ast.QuerySyntaxException: data_source_tab is not mapped [select d from data_source_tab d where d.url = ?1]
at org.hibernate.ejb.AbstractEntityManagerImpl.throwPersistenceException(AbstractEntityManagerImpl.java:601)
at org.hibernate.ejb.AbstractEntityManagerImpl.createQuery(AbstractEntityManagerImpl.java:96)
... 6 more
Caused by: org.hibernate.hql.ast.QuerySyntaxException: data_source_tab is not mapped [select d from data_source_tab d where d.url = ?1]
at org.hibernate.hql.ast.util.SessionFactoryHelper.requireClassPersister(SessionFactoryHelper.java:181)
at org.hibernate.hql.ast.tree.FromElementFactory.addFromElement(FromElementFactory.java:110)
at org.hibernate.hql.ast.tree.FromClause.addFromElement(FromClause.java:94)
at org.hibernate.hql.ast.HqlSqlWalker.createFromElement(HqlSqlWalker.java:316)
at org.hibernate.hql.antlr.HqlSqlBaseWalker.fromElement(HqlSqlBaseWalker.java:3228)
at org.hibernate.hql.antlr.HqlSqlBaseWalker.fromElementList(HqlSqlBaseWalker.java:3112)
at org.hibernate.hql.antlr.HqlSqlBaseWalker.fromClause(HqlSqlBaseWalker.java:720)
at org.hibernate.hql.antlr.HqlSqlBaseWalker.query(HqlSqlBaseWalker.java:571)
at org.hibernate.hql.antlr.HqlSqlBaseWalker.selectStatement(HqlSqlBaseWalker.java:288)
at org.hibernate.hql.antlr.HqlSqlBaseWalker.statement(HqlSqlBaseWalker.java:231)
at org.hibernate.hql.ast.QueryTranslatorImpl.analyze(QueryTranslatorImpl.java:254)
at org.hibernate.hql.ast.QueryTranslatorImpl.doCompile(QueryTranslatorImpl.java:185)
at org.hibernate.hql.ast.QueryTranslatorImpl.compile(QueryTranslatorImpl.java:136)
at org.hibernate.engine.query.HQLQueryPlan.<init>(HQLQueryPlan.java:101)
at org.hibernate.engine.query.HQLQueryPlan.<init>(HQLQueryPlan.java:80)
at org.hibernate.engine.query.QueryPlanCache.getHQLQueryPlan(QueryPlanCache.java:94)
at org.hibernate.impl.AbstractSessionImpl.getHQLQueryPlan(AbstractSessionImpl.java:156)
at org.hibernate.impl.AbstractSessionImpl.createQuery(AbstractSessionImpl.java:135)
at org.hibernate.impl.SessionImpl.createQuery(SessionImpl.java:1651)
at org.hibernate.ejb.AbstractEntityManagerImpl.createQuery(AbstractEntityManagerImpl.java:93)
If i directly add the jar in my build path, then it is working fine and it is creating the required tables. But the problem is, I get the hold on jar file at runtime.
Please help me with this.
Here is my classloader class :-
public class CustomURLClassLoader extends URLClassLoader
private static CustomURLClassLoader URLCLASSLOADER = null;
public CustomURLClassLoader(ClassLoader parent)
super(new URL[0], parent);
this.addAllJarsToClassPath();
* This method adds all the jars in the specified dirs and sub dirs
* recursively to the classpath. NOTE : Even though we use the term
* 'classpath' technically URLs are added to a list of URLs to search for
* classes and resources.
* @param dirContainingJars
* The directory containing jars
* @throws Exception
public void addJarsToClassPath() throws Exception
super.addURL("URL of jar file");
}

Answer 1

I don't know about hibernate, but EclipseLink allows passing in the classloader to the factory when it gets created as Shaun describes at:
JPA & Class Loaders
Best Regards,
Chris