Good sirs, I have a question. The school Java project I am currently working on requires me to have a USB Barcode Scanner as an external input to be connected to my laptop. I haven't actually bought the USB Scanner since it's quite expensive for a student. So I have to gather evidence that this Scanner would work with my program.
Would the Scanner be able to read from a barcode (presumably printed off online) and store it into a variable? If so, is it true that the action event for the press of the scanner would be read exactly like a keyboard keypress? If so, what would the line of code look like?
Also, if you could post your experiences with Barcode Scanners, or give any advice, such as which Scanner to buy, that would help alot. Cheers!
There are many reasons barcodes might not scan and most of them can be boiled down to one of three things—your equipment isn't suited to your barcodes, your scanner isn't being operated properly or your barcode labels aren't suited to your application or environment.
I recently had to implement a scanner system to interact with java.
I used Honeywell Voyager MS9540 USB barcode scanner.
As a default the scanner sent the data straight as keyboard input - no driver required.
But it was very easy to get this model to interact directly with java rather than using a keyboard hook (to use the barcodes as variables in java, as you mentioned).
This model has a setting to emulate a serial port, you can then read the scanned data using the javax.comm package. For me, this was much better than a keyboard hook to get the barcode data because the program does not need the focus before being able to interpret a scan (I would not want to create a global keyboard hook).
My java program reads all input from the specified serial port and writes the barcode to a database. I also setup the program to pass any unrecognized barcode scans to the keyboard (any barcode that my app did not create - I used a distinct signature on my barcodes) this was so it would work as a regular barcode scanner for any other apps that might read barcodes from the keyboard.
You could probably read data directly from any USB scanner (without the serial port emulation that this model has) by doing some intensive JNI coding but I wasn't prepared to take the time to work out the native code.
To configure this particular model for serial port emulation all you do is scan a specific barcode in this document with the scanner you want to configure. It is the barcode titled "Serial Emulation Mode".
This scanner does require a driver for serial port emulation. I found the implementation instructions and the needed drivers here (under the "software" tab). Download the package titled: "Honeywell Scanning and Mobility (HSM) USB Serial Driver". The PDF titled "HSM USB Serial Driver Getting Started Guide" had the instructions.
If you are not familiar with the javax.comm API. Please read the intro in this example by Rick Proctor - it tells you where to get the jar and where to put the files (javax.comm does not come standard with most java packages).
I'm sure there are other scanner models around that have serial port emulation (I don't work for Honeywell).
Here's a somewhat stripped down version of my barcode reader class:
package scanhandler; import java.awt.AWTException; import java.awt.Robot; import java.io.FileInputStream; import java.io.IOException; import java.io.InputStream; import java.sql.Connection; import java.util.Enumeration; import java.util.Properties; import java.util.TooManyListenersException; import javax.comm.CommPortIdentifier; import javax.comm.PortInUseException; import javax.comm.SerialPort; import javax.comm.SerialPortEvent; import javax.comm.SerialPortEventListener; import javax.comm.UnsupportedCommOperationException; public class ScanHandler implements Runnable, SerialPortEventListener { private static CommPortIdentifier myCommPortIdentifier; private static Enumeration portList; private static String TimeStamp; private static String driverClass; private static String connectionString; private static String comPort; private Connection myConnection; private InputStream myInputStream; private Robot myRobot; private SerialPort mySerialPort; private Thread myThread; public ScanHandler() { // open serial port try { TimeStamp = new java.util.Date().toString(); mySerialPort = (SerialPort) myCommPortIdentifier.open("ComControl", 2000); //System.out.println(TimeStamp + ": " + myCommPortIdentifier.getName() + " opened for scanner input"); } catch (PortInUseException e) { e.printStackTrace(); } // get serial input stream try { myInputStream = mySerialPort.getInputStream(); } catch (IOException e) { e.printStackTrace(); } // add an event listener on the port try { mySerialPort.addEventListener(this); } catch (TooManyListenersException e) { e.printStackTrace(); } mySerialPort.notifyOnDataAvailable(true); // set up the serial port properties try { mySerialPort.setSerialPortParams(9600, SerialPort.DATABITS_8, SerialPort.STOPBITS_1, SerialPort.PARITY_NONE); mySerialPort.setDTR(false); mySerialPort.setRTS(false); } catch (UnsupportedCommOperationException e) { e.printStackTrace(); } // make a robot to pass keyboard data try { myRobot = new Robot(); } catch (AWTException e) { e.printStackTrace(); } // create the thread myThread = new Thread(this); myThread.start(); } public void run() { try { Thread.sleep(100); } catch (InterruptedException e) {} } // on scan public void serialEvent(SerialPortEvent event) { if (event.getEventType() == SerialPortEvent.DATA_AVAILABLE) { StringBuilder myStringBuilder = new StringBuilder(); int c; try { // append the scanned data onto a string builder while ((c = myInputStream.read()) != 10){ if (c != 13) myStringBuilder.append((char) c); } // send to keyboard buffer if it the barcode doesn't start with '5' if (myStringBuilder.charAt(0) != '5') { for (int i = 0; i < myStringBuilder.length(); i++) { myRobot.keyPress((int) myStringBuilder.charAt(i)); myRobot.keyRelease((int) myStringBuilder.charAt(i)); } // here's the scanned barcode as a variable! } else { TimeStamp = new java.util.Date().toString(); System.out.println(TimeStamp + ": scanned input received:" + myStringBuilder.toString()); } // close the input stream myInputStream.close(); } catch (IOException e) { e.printStackTrace(); } } } public static void main(String[] args) { // read ScanHandler properties Properties myProperties = new Properties(); try { myProperties.load(new FileInputStream("config.properties")); comPort = myProperties.getProperty("ScanHandler.comPort"); } catch (IOException e) { e.printStackTrace(); } try { // get our pre-defined COM port myCommPortIdentifier = CommPortIdentifier.getPortIdentifier(comPort); ScanHandler reader = new ScanHandler(); } catch (Exception e) { TimeStamp = new java.util.Date().toString(); System.out.println(TimeStamp + ": " + comPort + " " + myCommPortIdentifier); System.out.println(TimeStamp + ": msg1 - " + e); } }; }
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