Hi,
I'm trying to use the Query by Example, but it does not work. It generates good SQL, but throws a JDBC excpetion:
java.sql.SQLException: The data flow is already closed.

Example example = Example.create(value);
result = session.createCriteria(value.getClass()).add(example).list();

Has anybody an Idea?
Simon.

Driver problem? BLOB in your example object which is from an older session? Impossible to tell with such a description.

Hi,
I'll try to be more precise. I use hibernate-2.1, with an Oracle 8i database.
I did several tests, and here is what I can say.
To open and close sessions, I use the class HibernateUtil given in the hibernate distrib.

Here is the code, in a method where I pass a parameter value of type Object.

List result = null;
try {
// this is to use find method
String request = "from " + value.getClass().getName();
// this is to use criteria
Example example = Example.create(value);

net.sf.hibernate.Session session = HibernateUtil.currentSession();
// this work properly
result = session.find(request);
HibernateUtil.closeSession();
session = HibernateUtil.currentSession();
// this work properly
result = session.find(request);
HibernateUtil.closeSession();

session = HibernateUtil.currentSession();
// this throws an exception.
result = session.createCriteria(value.getClass()).add(example).list();
HibernateUtil.closeSession();

} catch (HibernateException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

I can open and close sessions as long as I use the "find" method. I can't close a session if I want to use createCriteria: if one session has been closed, it throws an excpetion even if I get and open a new one. I can't figure out why.
The exception is this one and is thrown "after" the database has been queried.

net.sf.hibernate.JDBCException: SQLException occurred
at net.sf.hibernate.impl.SessionImpl.find(SessionImpl.java:3443)
at net.sf.hibernate.impl.CriteriaImpl.list(CriteriaImpl.java:177)

Caused by: java.sql.SQLException: Le flux de donn

maybe a connection pool problem try this

<property name="dbcp.maxActive">30</property>
<property name="dbcp.whenExhaustedAction">10</property>
<property name="dbcp.maxWait">120000</property>
<property name="dbcp.maxIdle">1</property>
<property name="dbcp.minIdle">0</property>
<property name="dbcp.ps.maxActive">10</property>
<property name="dbcp.ps.whenExhaustedAction">10</property>
<property name="dbcp.ps.maxWait">120000</property>
<property name="dbcp.ps.maxIdle">100</property>
<property name="dbcp.validationQuery">select 1 from dual</property>
<property name="dbcp.testOnBorrow">true</property>
<property name="dbcp.testOnReturn">false</property>

Maybe, my test application now work with this parameters
<property name="dbcp.maxActive">30</property>
<property name="dbcp.whenExhaustedAction">0</property>
<property name="dbcp.maxWait">120000</property>
<property name="dbcp.maxIdle">1</property>
<property name="dbcp.testOnBorrow">true</property>
<property name="dbcp.testOnReturn">false</property>
<property name="dbcp.ps.maxActive">10</property>
<property name="dbcp.ps.whenExhaustedAction">0</property>
<property name="dbcp.ps.maxWait">120000</property>
<property name="dbcp.ps.maxIdle">100</property>
(whenExhaustedAction can't take 10 for value), but I don't exactly understand why. The problem is that I did put the parameters on the data source used by my real application which is a struts application, but it still does not work. In fact it works for some classes but not for others. This behavior is very strange. I think I'll soon surrender and use the HQL even if was not my first choice.
Simon.