When I update a Maven project in Eclipse Juno (m2eclipse version 1.2.0) I sometimes get back an error message reporting:

“Updating Maven Project”. Unsupported IClasspathEntry kind=4

There are some strategies on how to solve this. The most successful in my case is to perform the following steps:

  1. Disable the Maven Nature of the project by Right-clicking the project and selecting Maven -> Disable Maven Nature
  2. Fire up a terminal in the projects directory and run mvn eclipse:clean  (Important: the project still needs to be open in Eclipse!)
  3. Re-enable the Maven Nature of your project by Right-clicking the project and selecting Configure -> Convert to Maven Project

If you now update the project again (Right-click on project -> Maven -> Update Project), everything should run smoothly. If not, you may find additional hints in the stackoverflow question where I drew this solution from.

Alternative

Another successful solution to this problem is to open up the .classpath file of your project and remove all entries with attribute kind=”var”.

Links

I recently noted that editing multiple XML files in Eclipse Juno results in slow reaction time or even causes Eclipse to hang completely. Fortunately, I found a quick fix for this: The XML editor may easily be replaced. The suggested editor in this case is Rinzo (see here).

The only thing you need to do is install the XML editor, Eclipse will care for replacing the built in XML editor:

  1. Select Help -> Install New Software…
  2. In the field Work with: add the URL http://editorxml.sourceforge.net/updates/
  3. Select Rinzo XML Editor and continue as usual (confirm license agreement etc.)

Links

If a single file becomes too large, e.g., in order to be sent via mail, you may want to split it into parts.

The command line tool tar is perfectly suitable for this, as it stems from an era where backups were regularly performed using tape drives (which have a certain size limit, of course). We will “misuse” this capability of tar in the following.

I suppose your file is called large_file.tar and you want to split it into parts of size 5MB (= 5120KB). The following instructions are not limited to tar files, any single file will do fine as well.

Splitting up the File

You start creating the archive with the following command:

As long as there is some unprocessed portion of the original file, you will be prompted for more “volumes”, i.e., more tapes. If you’d use a tape drive, you would now switch the tape, but in our setting we give an additional file for the second part by responding as follows  (note the preceeding “n ” in front of the file name):

For a 22.5MB large file the whole procedure already becomes quite tedious:

This question-answer game will continue until the whole file has been processed. If you want to save space, you may now compress the resulting archives:

Merging the Fragments

Of course, you (or the person who receives the fragmented archive from you) need to be able to restore the original file. The “mirror-symmetric” command to tar -c is tar -x:

The following procedure is identical to the other direction. If you use the compressed fragmented archives, you still need to decompress each of them:

Afterwards the fragmented archives are merged in order to restore the original file:

You should now see large_file.tar in the same directory.

Credits

Thanks to Paul Bradly, who described this procedure on his site.