java.lang.ClassFormatError

[Andreas Bobek <an...@gmx.net>]

Hello,

I use cayenne 2.0.4, tomcat 5.5 and jdk 1.5.
I generated (cgen) a superclass (_Basket) and a subclass (Basket) with no
problem and use them in a standard servlet. I even can create instances and
commit changes to the database. It all works fine.

But in certain circumstandes I get a java.lang.ClassFormatError (at most
"Invalid SourceFile attribute at constant pool index 63") in one of the
three classes depending on where I first of all access a java.util.List via
get(...).

For example in _Basket this would crash:

getObjectId().getIdSnapshot().get("foo")

or in my servlet:

List baskets = DataContext.createDataContext().performQuery(query);
Basket basket = (Basket) baskets.get(0);

I spent the last two days on that problem and meanwhile tested it at three
different machines (win2000, xp, suse). It's always the same.

Can somebody give me a hint? What I not tested yet is instead of using
cayenne.jar using the lighter version and put the dependencies on my own.
But could that really be the problem?

Thanks for helping, Andreas Bobek.

AW: java.lang.ClassFormatError

[Andreas Bobek <an...@uni-rostock.de>]

Ok I finally found the mistake I made. It has neither something to do with
Cayenne nor with Tomcat nor whatever. When building my project I use Ant and
I had a build file with a copy statement and a filter token expression which
was also applied to the binary class files...

http://ant.apache.org/manual/CoreTypes/filterset.html

Note: When a filterset is used in an operation, the files are processed in
text mode and the filters applied line by line. This means that the copy
operations will typically corrupt binary files. When applying filters you
should ensure that the set of files being filtered are all text files.

It tooks me quite long, original file and filtered file had exactly the same
length. There was only one different byte value...

(BTW: I never intended to replace filter text in binaries ;-)

Andreas.

AW: java.lang.ClassFormatError

[Andreas Bobek <an...@uni-rostock.de>]

I really don't get it, here is how I can reproduce this error:

Shop => Servlet
_Basket => Superclass
Basket => Subclass

Basket has no additional declarations.

Shop creates a new Basket (within doGet...):

Basket basket = (Basket)
DataContext.createDataContext().createAndRegisterNewObject(Basket.class);

_Basket contains this additional method (please don't care of the sense of
this code, it is here for demonstration only, this code is even never
called):

	public String test() {
		String name = ((DbAttribute)
Configuration.getSharedConfiguration()
	
.getDomain("na-domain").getMap("Basket").getObjEntity("Basket")
			.getDbEntity().getPrimaryKey().get(0)).getName();
		return (getObjectId().getIdSnapshot().get(name).toString());
	}


Scenario 1: as described above => ClassFormatError (see below)

Scenario 2: slightly modified the test method in _Basket:

	public String test() {
		Configuration conf = Configuration.getSharedConfiguration();
		String name = ((DbAttribute) conf
	
.getDomain("na-domain").getMap("Basket").getObjEntity("Basket")
			.getDbEntity().getPrimaryKey().get(0)).getName();
		return (getObjectId().getIdSnapshot().get(name).toString());
	}

=> it works!

Scenario 3: remove the creation of the new Basket object in Shop servlet =>
it works independent of what is desclared in _Basket. I suppose this is
because the class is never loaded.


The stack trace:

java.lang.ClassFormatError: Invalid this class index 2414 in constant pool
in class file test/cayenne/_Basket
	java.lang.ClassLoader.defineClass1(Native Method)
	java.lang.ClassLoader.defineClass(Unknown Source)
	java.security.SecureClassLoader.defineClass(Unknown Source)
	
org.apache.catalina.loader.WebappClassLoader.findClassInternal(WebappClassLo
ader.java:1629)
	
org.apache.catalina.loader.WebappClassLoader.findClass(WebappClassLoader.jav
a:850)
	
org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.jav
a:1299)
	
org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.jav
a:1181)
	java.lang.ClassLoader.loadClassInternal(Unknown Source)
	java.lang.ClassLoader.defineClass1(Native Method)
	java.lang.ClassLoader.defineClass(Unknown Source)
	java.security.SecureClassLoader.defineClass(Unknown Source)
	
org.apache.catalina.loader.WebappClassLoader.findClassInternal(WebappClassLo
ader.java:1629)
	
org.apache.catalina.loader.WebappClassLoader.findClass(WebappClassLoader.jav
a:850)
	
org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.jav
a:1299)
	
org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.jav
a:1181)
	java.lang.ClassLoader.loadClassInternal(Unknown Source)
	test.Shop.serveEmptyForm(Shop.java:75)
	test.Shop.doGet(Shop.java:47)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:689)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:802)


I suppose it is a version issue.
Tested on three machines, tomcat 5.5, jdk 1.5, cayenne 2.0.4

Thanks, Andreas.

Re: java.lang.ClassFormatError

[Malcolm Edgar <ma...@gmail.com>]

I would recommend including a stracktrace of the error, to help debug this.

regards Malcolm Edgar

On Mon, Apr 14, 2008 at 1:34 PM, Andreas Bobek <an...@gmx.net>
wrote:

> Hello,
>
> I use cayenne 2.0.4, tomcat 5.5 and jdk 1.5.
> I generated (cgen) a superclass (_Basket) and a subclass (Basket) with no
> problem and use them in a standard servlet. I even can create instances
> and
> commit changes to the database. It all works fine.
>
> But in certain circumstandes I get a java.lang.ClassFormatError (at most
> "Invalid SourceFile attribute at constant pool index 63") in one of the
> three classes depending on where I first of all access a java.util.List
> via
> get(...).
>
> For example in _Basket this would crash:
>
> getObjectId().getIdSnapshot().get("foo")
>
> or in my servlet:
>
> List baskets = DataContext.createDataContext().performQuery(query);
> Basket basket = (Basket) baskets.get(0);
>
> I spent the last two days on that problem and meanwhile tested it at three
> different machines (win2000, xp, suse). It's always the same.
>
> Can somebody give me a hint? What I not tested yet is instead of using
> cayenne.jar using the lighter version and put the dependencies on my own.
> But could that really be the problem?
>
> Thanks for helping, Andreas Bobek.
>
>