Hi there, after I tried everything for hours, I still haven't a result. I am not capable to close the reader in time. It still needs more entries in the console. That's my code now in the run method: public void run() { //schreib hier deinen Code while (true) { if (isInterrupted()) { System.out.println("Ich bin fertig"); return; } if (!isInterrupted()) { try { String zeile = reader.readLine(); if (!zeile.isEmpty()) { result.add(zeile); readStringCount.getAndIncrement(); } } catch (IOException e) { } } } } @Override public String toString () { return result.toString(); } } } and that's my output: 4 ee r f d #1:[ee] #2:[d] #3:[r, f] Ich bin fertig Ich bin fertig Ich bin fertig Process finished with exit code 0 As you can see, there is no automatic closure of the reader or shutdown of the Thread, when it is interrupted. It needs two more entries in the console. Can anybody explain to me, why? Thanks Claudia