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https://issues.apache.org/jira/browse/WICKET-6845?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17217911#comment-17217911
]
Martin Tzvetanov Grigorov commented on WICKET-6845:
---------------------------------------------------
Adding
{code:java}
if (usesDevelopmentConfig())
{
JavaSerializer serializer = new JavaSerializer(getName())
{
@Override
protected ObjectOutputStream newObjectOutputStream(OutputStream out)
throws IOException
{
IObjectChecker checker = new SessionChecker();
return new CheckingObjectOutputStream(out, checker);
}
};
getFrameworkSettings().setSerializer(serializer);
}
{code}
to MyApplication#init() produces this:
{code:java}
[qtp385242642-17] ERROR org.apache.wicket.serialize.java.JavaSerializer - Error
serializing object class com.test.HomePage [object=[Page class =
com.test.HomePage, id = 0, render count = 1]]
org.apache.wicket.core.util.objects.checker.CheckingObjectOutputStream$ObjectCheckException:
Trying to serialize the Wicket Session!
A problem occurred while checking object with type:
org.apache.wicket.protocol.http.WebSession
Field hierarchy is:
[class=com.test.HomePage, path=0]
private final com.test.TestBean com.test.HomePage.testBean
[class=com.test.TestBean]
private final org.apache.wicket.Session com.test.TestBean.session
[class=org.apache.wicket.protocol.http.WebSession] <----- field that is causing
the problem
at
org.apache.wicket.core.util.objects.checker.CheckingObjectOutputStream.internalCheck(CheckingObjectOutputStream.java:371)
at
org.apache.wicket.core.util.objects.checker.CheckingObjectOutputStream.check(CheckingObjectOutputStream.java:354)
... {code}
but I am not sure whether we want to enable this checker for everyone.
At the moment Wicket first serializes the page without checking and if it fails
with NotSerializableException then it uses
org.apache.wicket.core.util.objects.checker.ObjectSerializationChecker to print
which field is not Serializable. I.e. the extra cost for the checking is
executed only if there is a problem.
But in the current case one has to enable SessionChecker by default in DEV mode
to find the problem. Otherwise StackOverflowError won't allow the second run of
the serialization with the checkers.
> stackoverflow while serializing a page containing a reference to session
> ------------------------------------------------------------------------
>
> Key: WICKET-6845
> URL: https://issues.apache.org/jira/browse/WICKET-6845
> Project: Wicket
> Issue Type: Bug
> Components: wicket
> Affects Versions: 9.0.0, 9.1.0
> Reporter: Ernesto Reinaldo Barreiro
> Assignee: Martin Tzvetanov Grigorov
> Priority: Major
> Attachments: session-serialization.tar.gz
>
>
> Something has changed in the way pages are serialized in wicket 9.x thus that
> if a page has a reference to session serialization enters in a loop causing
> an stack overflow. See attached project. While there is no reasons to keep a
> reference to session, and I have fixed that in our legacy code causing this
> problem, it would be nice to avoid server crashing because of this (and log
> a huge warning for users to note).
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