gzip --rsyncable does not zip from java using Runtime.exec() - gzip

Question

I am trying to run gzip with the --rsyncable option - it works fine when run it in a terminal window (I am on Mac OS) - but it does not work when I run it from java with the following code.
Any idea what the problem could be?
import java.io.BufferedReader;
import java.io.File;
import java.io.IOException;
import java.io.InputStreamReader;
public class RsyncIssue {
public static void printOutput(Process p) throws IOException{
String ss;
BufferedReader inReader = new BufferedReader(new InputStreamReader(p.getInputStream()));
while((ss = inReader.readLine()) != null ){
System.out.println("[IN] "+ ss);
}
}
public static void main(String[] args) throws IOException {
File f = new File("Test.ext");
if( !f.exists())
{
f.createNewFile();
}
String zipCommand = "gzip --rsyncable " + f.getCanonicalPath();
System.out.println("Zipping file : " + f.getName() );
System.out.println("Zipping command: " + zipCommand);
Process p = Runtime.getRuntime().exec(zipCommand);
printOutput(p);
File zipfile = new File(f.getCanonicalPath()+".gz");
if( !zipfile.exists())
{
throw new RuntimeException("zip file does not exist " + zipfile.getAbsolutePath());
}
}
}

Answer 1

Things you should do:
Call p.waitFor() so that execution blocks until the execution has completed.
Then call p.exitValue() and compare to 0 to see if there was an error.
In printOutput also read the process's getErrorStream() to view any errors.
Check that --rsyncable is available on your platform, it is not a universally-available gzip option.