For older JVM, in linux...
private static String getPid() throws IOException {
byte[] bo = new byte[256];
InputStream is = new FileInputStream("/proc/self/stat");
is.read(bo);
for (int i = 0; i < bo.length; i++) {
if ((bo[i] < '0') || (bo[i] > '9')) {
return new String(bo, 0, i);
}
}
return "-1";
}