[JIRA] Created: (CAY-796) Deserialization of DataContext fails when useSharedCache is false

From: bob schellink (JIRA) ("bob)
Date: Mon Jun 04 2007 - 05:55:28 EDT

  • Next message: Lachlan Deck (JIRA): "[JIRA] Created: (CAY-797) Lifecycle callbacks *CallbackInterceptor concept introduces problems for testing equality of contexts"

    Deserialization of DataContext fails when useSharedCache is false
    -----------------------------------------------------------------

                     Key: CAY-796
                     URL: https://issues.apache.org/cayenne/browse/CAY-796
                 Project: Cayenne
              Issue Type: Bug
              Components: Cayenne Core Library
        Affects Versions: 1.2 [STABLE], 2.0 [STABLE]
             Environment: JDK 1.5, Windows XP
                Reporter: bob schellink
                Assignee: Andrus Adamchik

    Sometimes while developing with Tomcat I get the exception below. This occurs when DataContext is serialized.

    Exception in thread "main" org.objectstyle.cayenne.CayenneRuntimeException: [v.1.2.3 May 6 2007] Commit Exception
    org.objectstyle.cayenne.access.DataContext.flushToParent(DataContext.java:1290)
    org.objectstyle.cayenne.access.DataContext.commitChanges(DataContext.java:1166)
    test.SerializeDCTest.main(SerializeDCTest.java:29)

    Caused by: java.lang.NullPointerException
    org.objectstyle.cayenne.access.DataRowStore.sendUpdateNotification(DataRowStore.java:709)
    org.objectstyle.cayenne.access.DataRowStore.processSnapshotChanges(DataRowStore.java:574)
    org.objectstyle.cayenne.access.DataDomainFlushAction.postprocess(DataDomainFlushAction.java:278)
    org.objectstyle.cayenne.access.DataDomainFlushAction.flush(DataDomainFlushAction.java:178)
    org.objectstyle.cayenne.access.DataDomain.onSyncFlush(DataDomain.java:846)
    org.objectstyle.cayenne.access.DataDomain$2.transform(DataDomain.java:817)
    org.objectstyle.cayenne.access.DataDomain.runInTransaction(DataDomain.java:872)
    org.objectstyle.cayenne.access.DataDomain.onSync(DataDomain.java:814)
    org.objectstyle.cayenne.access.DataContext.flushToParent(DataContext.java:1262)

    Here is a little test to reproduce the error:

    package test;

    import test.cayenne.Employee;
    import java.io.ByteArrayInputStream;
    import java.io.ByteArrayOutputStream;
    import java.io.ObjectInputStream;
    import java.io.ObjectOutputStream;
    import java.util.List;
    import org.objectstyle.cayenne.DataObjectUtils;
    import org.objectstyle.cayenne.access.DataContext;
    import org.objectstyle.cayenne.query.SelectQuery;

    public class SerializeDCTest {

        public SerializeDCTest() {
        }

        public static void main(String[] args) {
            //boolean useSharedCache = true; //works
            boolean useSharedCache = false;
            DataContext context = DataContext.createDataContext(useSharedCache);
            context = serializeDC(context);
            Employee emp = (Employee) DataObjectUtils.objectForPK(context, Employee.class, 740);
            emp.setFirstname("test" + Math.random());
            context.commitChanges();
        }

        public static DataContext serializeDC(DataContext dc) {
            try {
                ByteArrayOutputStream bos = new ByteArrayOutputStream();
                ObjectOutputStream oos = new ObjectOutputStream(bos);
                oos.writeObject(dc);

                ByteArrayInputStream is = new ByteArrayInputStream(bos.toByteArray());
                ObjectInputStream ois = new ObjectInputStream(is);
                DataContext result = (DataContext) ois.readObject();
                return result;

            } catch (Exception ex) {
                throw new RuntimeException("DataContext serialization failed", ex);
            }
        }
    }

    Note that if useSharedCache = true, then it works fine. 

    -- 
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.

    This archive was generated by hypermail 2.0.0 : Mon Jun 04 2007 - 05:55:53 EDT