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 JavaTM 2 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.
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.