question: public void executeCommand ( String shellCmd ) { if ( mThread != null && mThread . isAlive ( ) ) { mShellThread . stop ( ) ; mResults = new StringBuilder ( ) ; } mCurrentCommand = shellCmd ; mShellThread = new ShellThread ( ) ; mThread = new Thread ( mShellThread ) ; mThread . start ( ) ; }
target:  Executes a given command, if the previous command is still running, it's thread will be stopped.