ava.lang.ClassFormatError: Unknown constant tag 0 in class file

Posted on 2007-11-20
Last Modified: 2013-11-23

java.lang.ClassFormatError: Unknown constant tag 0 in class file
Question by:bob_hewitt
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LVL 86

Expert Comment

ID: 20323492
Try recompiling
LVL 92

Accepted Solution

objects earned 125 total points
ID: 20323563
looks like its not a class file that you are running

Author Closing Comment

ID: 31427384
Turns out I had used 'text' mode rather than 'binary' mode, when copying the class files from Windows to Unix. Thanks!
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LVL 86

Expert Comment

ID: 20324064
>>looks like its not a class file that you are running

You won't get that error message from a file that's not a class file. And if you did, why would you be trying to run something that's *not* a class file?

Author Comment

ID: 20324318
Maybe it's yet to appear, but I found (and replied) that it was due to an SCP file transfer (of a binary 'class' file) in ascii mode from Windows to Unix.  

(1)  I did a hex dump of the files on their respective computers, and the two copies of the same class file differed.

(2)  I did the transfer again in binary mode and the class file now works. (and, the two files no longer differ.)

QED  Thanks again, folks.
LVL 92

Expert Comment

ID: 20324387
that would do it, the reulting file would then no longer be as valid class file

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