Thank you Lars, unfortunately we still haven't found any actual cglib
proxies in our session. So it goes.
- Scott
On Thu, Mar 27, 2008 at 7:41 AM, lars vonk <[EMAIL PROTECTED]> wrote:
> Hi,
>
> I did some more research (since I am intrigued by the subject) with the
> following results:
>
> - If you have enhanced cglib classes in your session and they are serialized
> and later deserialized by a different jvm (for instance after restart)
> you'll get a ClassNotFoundException. Since it can't find the enhanced class.
> - Like the explanation on the cglib site you'll need to override the
> writeReplace method in the object containing the cglib enhanced classes to
> replace them with non enhanced counterparts.
>
> Here is testcode to proof it:
> ======================================
> Dummy Session object containing the cglib enhanced class
> ======================================
>
> public class Session implements Serializable {
> private static final long serialVersionUID = 7348708008236878630L;
> private TestObject testObject;
>
> public void setTestObject(TestObject testObject) {
> this.testObject = testObject;
> }
> }
> ======================================
> TestObject that will be enhanced by cglib
> ======================================
> public class TestObject implements Serializable {
> private static final long serialVersionUID = -5780038574171745351L;
> private String text = "hallo";
>
> public String getText() {
> return text;
> }
> }
>
>
> ======================================
> The serializer
> ======================================
>
> import java.io.File;
> import java.io.FileOutputStream;
> import java.io.ObjectOutputStream;
>
> import net.sf.cglib.proxy.Enhancer;
> import net.sf.cglib.proxy.MethodInterceptor;
>
> public class Serializer {
>
> static final File TEST_FILE = new File("/tmp/Session.obj");
>
> public static void main(String[] args) throws Exception {
> Enhancer enhancer = new Enhancer();
> enhancer.setSuperclass(TestObject.class);
> enhancer.setCallbackType(MethodInterceptor.class);
> Object object = enhancer.createClass().newInstance();
> TestObject testObject = TestObject.class.cast(object);
>
> System.out.println("Text: " + testObject.getText());
> if(TEST_FILE.exists()) {
> System.out.println("Deleting existing file");
> TEST_FILE.delete();
> }
> Session session = new Session();
> session.setTestObject(testObject);
>
> FileOutputStream fileOutputStream = new FileOutputStream(TEST_FILE);
> ObjectOutputStream outputStream = new
> ObjectOutputStream(fileOutputStream);
> outputStream.writeObject(session);
> outputStream.close();
>
>
> if(TEST_FILE.exists()) {
> System.out.println("File created!");
> } else {
> System.out.println("File NOT created!");
>
> }
> }
>
> }
>
> ======================================
> The deserializer
> ======================================
> public class DeSerializer {
>
> public static void main(String[] args) throws Exception {
> if(!Serializer.TEST_FILE.exists()) {
> System.out.println("Test file does not exist.");
> return;
> }
>
> FileInputStream fileInputStream = new FileInputStream(
> Serializer.TEST_FILE);
> ObjectInputStream inputStream = new
> ObjectInputStream(fileInputStream);
> Object object = inputStream.readObject();
> System.out.println("Object: "+ object.getClass() + " read from
> disk");
>
> }
>
> }
>
>
> If you'll first run the Serializer and then the DeSerializer you'll see the
> ClassNotFoundException with a mesage something like:
> TestObject$$EnhancerByCGLIB$$
>
> If you add the following method in the Session:
>
> private Object writeReplace() throws ObjectStreamException {
> System.out.println("in write replace");
> this.testObject = new TestObject();
> return this;
> }
>
> And run it again it will work smoothly. The object returned by writeReplace
> will actually be stored in the stream.
>
> This does not exactly solve your problem I guess (no
> StreamCorruptedException here...), but it does mean you can't have cglib
> enhanced classes in your session. Or was this already a known issues?
>
> Lars
>
>
>
> On Thu, Mar 27, 2008 at 12:19 PM, lars vonk <[EMAIL PROTECTED]> wrote:
>
> > Hi,
> >
> > Assuming you use CGLib:
> >
> > CGLib classes could cause this problem, it makes sense since:
> >
> > - It does not occur in a single jvm, the enhanced classes are available
> > there.
> > - It does occur when read from a different jvm *or* restarted jvm: The
> > enhanced classes are no longer available there.
> >
> > According to the CGLib site there is a way around this. See
> > http://cglib.sourceforge.net/howto.html
> >
> > CGLIB and JAVA Serialization
> > >
> > > JAVA objects can be serialized to binary streams, it is used to
> > > implement RMI too. Serialization needs to load class before to
> deserialize
> > > object data. It is possible there is no generated class on client or
> server
> > > for unmarshaled object, but serialization lets to replace objects in
> stream
> > > (writeReplace/readResolve contract). To add "writeReplace" method to
> proxy
> > > class declare this method in interface with exact signature specified by
> > > JAVA serialization. Implement writeReplace in interceptor. Proxy object
> can
> > > be replaced by handle, object stream invokes "readResolve" before to
> > > deserialize hanle. Generate or find proxy class in "readResolve" method
> > > before to deserialize hanle and return proxy instance.
> > >
> >
> > The description is a bit cryptic though.... But my understanding is that
> > when you implement the writeReplace and readResolve methods in your
> enhanced
> > class it should work.
> >
> > Hopes this helps.
> >
> > Lars
> >
> >
> >
> > On Wed, Mar 26, 2008 at 5:36 PM, Scott Swank <[EMAIL PROTECTED]>
> > wrote:
> >
> > > That did not take care of our problem. We are examining our session
> > > to see whether it mistakenly contains some sort of cglib proxy -- our
> > > typesafe model, or maybe something from Hibernate.
> > >
> > > Thank you again for the help.
> > >
> > > Scott
> > >
> > > On Tue, Mar 25, 2008 at 9:55 AM, Scott Swank <[EMAIL PROTECTED]>
> > > wrote:
> > > > Thank you. We'll give that a try and let you know the results.
> > > >
> > > >
> > > >
> > > > On Mon, Mar 24, 2008 at 11:43 PM, Igor Vaynberg <
> > > [EMAIL PROTECTED]> wrote:
> > > > > see WICKET-1445. upgrade wicket to trunk and try again.
> > > > >
> > > > > -igor
> > > > >
> > > > >
> > > > >
> > > > >
> > > > > On Mon, Mar 24, 2008 at 3:15 PM, Scott Swank <
> > > [EMAIL PROTECTED]> wrote:
> > > > > > We are trying to get clustering working with Wicket 1.3.2 (on
> > > JBoss
> > > > > > 4.3.0) and we get the following exception when one node fails
> > > over to
> > > > > > another node. Has anyone seen anything like this before? Any
> > > > > > suggestions/guesses?
> > > > > >
> > > > > > Thank you,
> > > > > > Scott
> > > > > >
> > > > > > 15:02:17,320 ERROR [RequestCycle] Could not deserialize object
> > > using `org.apache
> > > > > >
> > > .wicket.util.io.IObjectStreamFactory$DefaultObjectStreamFactory` object
> > > factory
> > > > > > java.lang.RuntimeException: Could not deserialize object using
> > > `org.apache.wicke
> > > > > >
> t.util.io.IObjectStreamFactory$DefaultObjectStreamFactory`object factory
> > > > > > at org.apache.wicket.util.lang.Objects.byteArrayToObject
> > > (Objects.java:40
> > > > > > 6)
> > > > > > at
> > > org.apache.wicket.protocol.http.pagestore.AbstractPageStore.deseriali
> > > > > > zePage(AbstractPageStore.java:228)
> > > > > > at
> > > org.apache.wicket.protocol.http.pagestore.DiskPageStore.getPage(DiskP
> > > > > > ageStore.java:706)
> > > > > > at
> > > org.apache.wicket.protocol.http.pagestore.DiskPageStore.convertToPage
> > > > > > (DiskPageStore.java:1218)
> > > > > > at
> > > org.apache.wicket.protocol.http.SecondLevelCacheSessionStore$SecondLe
> > > > > > velCachePageMap.getLastPage(SecondLevelCacheSessionStore.java
> > > :228)
> > > > > > at
> > > org.apache.wicket.protocol.http.SecondLevelCacheSessionStore$SecondLe
> > > > > > velCachePageMap.get(SecondLevelCacheSessionStore.java:296)
> > > > > > at org.apache.wicket.Session.getPage(Session.java:751)
> > > > > > at
> > > org.apache.wicket.request.AbstractRequestCycleProcessor.resolveRender
> > > > > > edPage(AbstractRequestCycleProcessor.java:448)
> > > > > > at
> > > org.apache.wicket.protocol.http.WebRequestCycleProcessor.resolve(WebR
> > > > > > equestCycleProcessor.java:139)
> > > > > > at org.apache.wicket.RequestCycle.step(RequestCycle.java
> > > :1224)
> > > > > > at org.apache.wicket.RequestCycle.steps(
> > > RequestCycle.java:1330)
> > > > > > at org.apache.wicket.RequestCycle.request(
> > > RequestCycle.java:493)
> > > > > > at org.apache.wicket.protocol.http.WicketFilter.doGet(
> > > WicketFilter.java:
> > > > > > 358)
> > > > > > at org.apache.wicket.protocol.http.WicketServlet.doGet(
> > > WicketServlet.jav
> > > > > > a:124)
> > > > > > at javax.servlet.http.HttpServlet.service(
> > > HttpServlet.java:690)
> > > > > > at javax.servlet.http.HttpServlet.service(
> > > HttpServlet.java:803)
> > > > > > at
> > > org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Appl
> > > > > > icationFilterChain.java:290)
> > > > > > at
> > > org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationF
> > > > > > ilterChain.java:206)
> > > > > > at
> > > com.vegas.ui.filter.CustomerFacingClientContextFilter.doFilter(Custom
> > > > > > erFacingClientContextFilter.java:42)
> > > > > > at
> > > org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Appl
> > > > > > icationFilterChain.java:235)
> > > > > > at
> > > org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationF
> > > > > > ilterChain.java:206)
> > > > > > at com.vegas.ui.filter.HibernateFilter.doFilter(
> > > HibernateFilter.java:37)
> > > > > >
> > > > > > at
> > > org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Appl
> > > > > > icationFilterChain.java:235)
> > > > > > at
> > > org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationF
> > > > > > ilterChain.java:206)
> > > > > > at
> > > org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFi
> > > > > > lter.java:96)
> > > > > > at
> > > org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Appl
> > > > > > icationFilterChain.java:235)
> > > > > > at
> > > org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationF
> > > > > > ilterChain.java:206)
> > > > > > at org.apache.catalina.core.StandardWrapperValve.invoke
> > > (StandardWrapperV
> > > > > > alve.java:230)
> > > > > > at org.apache.catalina.core.StandardContextValve.invoke
> > > (StandardContextV
> > > > > > alve.java:175)
> > > > > > at
> > > org.jboss.web.tomcat.security.SecurityAssociationValve.invoke(Securit
> > > > > > yAssociationValve.java:179)
> > > > > > at
> > > org.jboss.web.tomcat.service.session.ClusteredSessionValve.invoke(Clu
> > > > > > steredSessionValve.java:87)
> > > > > > at
> > > org.jboss.web.tomcat.service.session.JvmRouteValve.invoke(JvmRouteVal
> > > > > > ve.java:84)
> > > > > > at org.jboss.web.tomcat.security.JaccContextValve.invoke
> > > (JaccContextValv
> > > > > > e.java:84)
> > > > > > at org.apache.catalina.core.StandardHostValve.invoke(
> > > StandardHostValve.j
> > > > > > ava:128)
> > > > > > at org.apache.catalina.valves.ErrorReportValve.invoke(
> > > ErrorReportValve.j
> > > > > > ava:104)
> > > > > > at
> > > org.jboss.web.tomcat.service.jca.CachedConnectionValve.invoke(CachedC
> > > > > > onnectionValve.java:157)
> > > > > > at org.apache.catalina.core.StandardEngineValve.invoke
> > > (StandardEngineVal
> > > > > > ve.java:109)
> > > > > > at org.apache.catalina.connector.CoyoteAdapter.service(
> > > CoyoteAdapter.jav
> > > > > > a:241)
> > > > > > at org.apache.coyote.ajp.AjpProcessor.process(
> > > AjpProcessor.java:437)
> > > > > > at
> > > org.apache.coyote.ajp.AjpProtocol$AjpConnectionHandler.process(AjpPro
> > > > > > tocol.java:381)
> > > > > > at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(
> > > JIoEndpoint.java:44
> > > > > > 7)
> > > > > > at java.lang.Thread.run(Unknown Source)
> > > > > > Caused by: java.io.StreamCorruptedException: invalid type code:
> > > B8
> > > > > > at java.io.ObjectInputStream.readObject0(Unknown Source)
> > > > > > at java.io.ObjectInputStream.defaultReadFields(Unknown
> > > Source)
> > > > > > at java.io.ObjectInputStream.readSerialData(Unknown
> > > Source)
> > > > > > at java.io.ObjectInputStream.readOrdinaryObject(Unknown
> > > Source)
> > > > > > at java.io.ObjectInputStream.readObject0(Unknown Source)
> > > > > > at java.io.ObjectInputStream.readObject(Unknown Source)
> > > > > > at org.apache.wicket.util.lang.Objects.byteArrayToObject
> > > (Objects.java:39
> > > > > > 2)
> > > > > > ... 41 more
> > > > > >
> > > > >
> > > > >
> > > > > >
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