$ perl
open PIPE, "| java -jar java_program.jar";
print PIPE "$string";
close(PIPE);
^Z
Exception in thread "main" java.util.zip.ZipException: The system cannot find the file specified
        at java.util.zip.ZipFile.open(Native Method)
        at java.util.zip.ZipFile.<init>(Unknown Source)
        at java.util.jar.JarFile.<init>(Unknown Source)
        at java.util.jar.JarFile.<init>(Unknown Source)

$