try {
            
    /*** Init GPIO port(s) for input ***/
    
    // Open file handles to GPIO port unexport and export controls
    FileWriter unexportFile = 
            new FileWriter("/sys/class/gpio/unexport");
    FileWriter exportFile = 
            new FileWriter("/sys/class/gpio/export");
    for (String gpioChannel : GpioChannels) {
        System.out.println(gpioChannel);
             // Reset the port
        File exportFileCheck = new 
	    File("/sys/class/gpio/gpio"+gpioChannel);
        if (exportFileCheck.exists()) {
            unexportFile.write(gpioChannel);
            unexportFile.flush();
        }
    
        // Set the port for use
        exportFile.write(gpioChannel);   
        exportFile.flush();
         // Open file handle to input/output direction control of port
        FileWriter directionFile =
            new FileWriter("/sys/class/gpio/gpio" + gpioChannel + 
                "/direction");
    
        // Set port for input
        directionFile.write(GPIO_IN);
    }
    
    /*** Read data from each GPIO port ***/
    RandomAccessFile[] raf = new RandomAccessFile[GpioChannels.length];
    
    int sleepPeriod = 10;
    final int MAXBUF = 256;
    
    byte[] inBytes = new byte[MAXBUF]; 
    String inLine;
    
    int zeroCounter = 0;
    
    // Get current timestamp with Calendar()
    Calendar cal;
    DateFormat dateFormat = 
            new SimpleDateFormat("yyyy/MM/dd HH:mm:ss.SSS");
    String dateStr;
    
    // Open RandomAccessFile handle to each GPIO port
    for (int channum=0; channum < raf.length; channum++) {
        raf[channum] = new RandomAccessFile("/sys/class/gpio/gpio"
                + GpioChannels[channum] + "/value", "r");
    }
    
    // Loop forever
    while (true) {
        
        // Get current timestamp for latest event
        cal = Calendar.getInstance();
        dateStr = dateFormat.format(cal.getTime());

        // Use RandomAccessFile handle to read in GPIO port value
        for (int channum=0; channum < raf.length; channum++) {
            
            // Reset file seek pointer to read latest value of GPIO port
            raf[channum].seek(0);
            raf[channum].read(inBytes);
            inLine = new String(inBytes);
            
            // Check if any value was read
            if (inLine != null) {
                
                // Compress 0 values so we don't see too many 
                //   unimportant lines
                if (inLine.startsWith("0")) {
                    if (zeroCounter < 1000) {
                        zeroCounter++;
                    } else {
                        System.out.print(dateStr + ": " + inLine);
                        zeroCounter = 0;
                    }
                } else {
                    // Else, specially mark value non-zero value
                    System.out.print("***" + dateStr + ": " + inLine);
                    zeroCounter = 0;
                }
            }
             // Wait for a while
            java.lang.Thread.sleep(sleepPeriod);

        }
    }
} catch (Exception exception) {
   exception.printStackTrace();
}