extcheck - A utility to detect jar conflicts
extcheck detects version conflicts between a target jar file
and currently installed extension jar files.
SYNOPSIS
extcheck [ -verbose ] targetfile.jar
DESCRIPTION
The extcheck utility checks a specified Jar file for title
and version conflicts with any extensions installed in the
Java™ SDK. Before installing an extension, you can use this
utility to see if the same or a more recent version of the
extension is already installed.
The extcheck utility compares the
Specification-title and
Specification-version headers in the manifest of
targetfile.jar file against the corresponding headers
in all Jar files currently installed in the extension directory.
(The extension directory is jre\lib\ext by default.) The
extcheck utility compares version numbers in the same way as
the method java.lang.Package.isCompatibleWith.
If no conflict is detected, the return code is 0.
If the manifest of any of the jar file in the extensions
directory has the same Specification-title and the
same or a newer Specification-version number, a
non-zero error code is returned. A non-zero error code is also
returned if targetfile.jar does not have the
Specification-title or
Specification-version attributes in its manifest.
- -verbose
- Lists Jar files in the extension directory as they are checked.
Additionally, manifest attributes of the target jar file and any
conflicting jar files are also reported.
- -Joption
- Pass option to the Java virtual machine, where
option is one of the options described on the reference page
for the java application launcher. For
example, -J-Xms48m sets the startup memory to 48
megabytes.
SEE ALSO
jar
