JAR file

[Frank Lin]

What is the easiest way to find out if a desired class file is in a (or better in a number of) JAR file(s)?

[Madhav Lakkapragada]

hmmm.....just now I answered a similar qstn in this post.
I would use a list. Not sure if there is a better way.
The std options for the jar command are:

Usage: jar {ctxu}[vfm0M] [jar-file] [manifest-file] [-C dir] files ...
Options:
    -c  create new archive
    -t  list table of contents for archive
    -x  extract named (or all) files from archive
    -u  update existing archive
    -v  generate verbose output on standard output
    -f  specify archive file name
    -m  include manifest information from specified manifest file
    -0  store only; use no ZIP compression
    -M  Do not create a manifest file for the entries
    -C  change to the specified directory and include the following file
If any file is a directory then it is processed recursively.
The manifest file name and the archive file name needs to be specified
in the same order the 'm' and 'f' flags are specified.
Example 1: to archive two class files into an archive called classes.jar:
       jar cvf classes.jar Foo.class Bar.class
Example 2: use an existing manifest file 'mymanifest' and archive all the
           files in the foo/ directory into 'classes.jar':
       jar cvfm classes.jar mymanifest -C foo/ .

regds.
- satya

[Sandeep Jain]

I dont think So there are any options to check only if a particular file exist or not.
What u can do is list all the file in ur jar file and check it if the required file is there or not.
eg :-
jar -vtf rt.jar
------------------
Sandeep Jain

[Sandeep Jain]

I dont think So there are any options to check only if a particular file exist or not.
What u can do is list all the file in ur jar file and check it if the required file is there or not.
eg :-
jar -vtf rt.jar
------------------
Sandeep Jain

[Frank Lin]

Actually, it can be easily done with one JAR file by using the jar and piped find command in windows or grep in unix
jar -tvf rt.jar | find "ClassName"
But I was looking for some kind of utility program that searches all jar/zip files in the classpath and list them out. I guess I need to create my own.

[A raviprasad]

There is free java code "jwhich.java" which will help U locate the class file in the class path. Hope this may add to the info U have obtained.
---------------------------------
public class JWhich {
/**
* Prints the absolute pathname of the class file
* containing the specified class name, as prescribed
* by the current classpath.
*
* @param className Name of the class.
*/
public static void which(String className) {
if (!className.startsWith("/")) {
className = "/" + className;
}
className = className.replace('.', '/');
className = className + ".class";
java.net.URL classUrl =
new JWhich().getClass().getResource(className);
if (classUrl != null) {
System.out.println("\nClass '" + className +
"' found in \n'" + classUrl.getFile() + "'");
} else {
System.out.println("\nClass '" + className +
"' not found in \n'" +
System.getProperty("java.class.path") + "'");
}
}
public static void main(String args[]) {
if (args.length > 0) {
JWhich.which(args[0]);
} else {
System.err.println("Usage: java JWhich <classname>");
}
}
}

[Kalpesh Soni]

I wrote this myself a long time back to "jwhich dir"

JWhichDir

see
http://www.geocities.com/kalpeshsoni/JWhichDir.zip
[ September 22, 2008: Message edited by: Kalpesh Soni ]