www.pudn.com > 使用 Java 读取条形码代码文件.rar > BarCodeScanner.java

package com.jmart.barcode; 
 
import java.io.*; 
import javax.comm.*; 
import java.util.*; 
import com.jmart.event.*; 
 
/** 
 * The implementation of the BarCodeScanner.  It opens the port specified to listen for data through 
 * the InputStream.  Events are thrown when data is available in the InputStream. 
 * 
BarCodeScanner wraps these basic SerialPortEvents into a BarCodeScanner listener/event interface, 
 * which more closely matches the java.awt.event listener/event model. 
 * 
 The settings are currently set for the common barcode scanners found on the market.  To find settings 
 * for a specific barcode scanner, see the manufacturer settings of your particular gun and adjust the code 
 * accordingly. 
 */ 
  
public class BarCodeScanner implements SerialPortEventListener { 
 
	 // The portname that the barcode scanner is connected to (customize for your machine) 
	private final static java.lang.String BARCODE_SCANNER_PORTNAME = "COM4"; 
	 
	//	The timeout waiting for the serial port to respond 
	private final static int TIMEOUT_TIME = 3000; 
 
	//	The baud rate of the bar code scanner  
	private final static int BAUD_RATE = 38400; 
 
	// The buffer size to read in data 
	private final static int BUFFER_SIZE = 200; 
 
	private int length; 
	private javax.comm.SerialPort serialPort; 
	private java.io.BufferedInputStream inputStream; 
	private java.util.Vector listeners; 
	private java.lang.String barCodeString; 
	private BarCodeThread barcodeThread; 
 
/** 
 * Creates the BarCodeScanner object 
 */ 
public BarCodeScanner(int length) throws Exception 
{ 
	listeners = new java.util.Vector(); 
	this.length = length; 
	 
	try 
	{ 
		// Set up the barcode scanner 
		CommPortIdentifier commPort = CommPortIdentifier.getPortIdentifier(BARCODE_SCANNER_PORTNAME); 
		serialPort = (SerialPort)commPort.open("Barcode Scanner", TIMEOUT_TIME); 
		inputStream = new BufferedInputStream(serialPort.getInputStream()); 
		serialPort.setInputBufferSize(BUFFER_SIZE); 
		serialPort.addEventListener(this); 
		serialPort.notifyOnDataAvailable(true); 
		// Each barcode scanner will have its own settings - see manufacturer specifics for settings of each gun 
        serialPort.setSerialPortParams(BAUD_RATE, SerialPort.DATABITS_8, SerialPort.STOPBITS_1, SerialPort.PARITY_NONE); 
	} 
	catch (NoSuchPortException e)  
	{  
		throw e; 
	} 
	catch (PortInUseException e)  
	{ 
		throw e; 
	} 
	catch (IOException e) 
	{  
		throw e; 
	} 
	catch (java.util.TooManyListenersException e)  
	{  
		throw e; 
	} 
	catch (UnsupportedCommOperationException e) 
	{  
		throw e; 
	} 
} 
 
public synchronized void addBarCodeListener(BarCodeListener b)  
{ 
	if ( ! listeners.contains(b))	 
		listeners.add(b);	 
} 
 
public void close()  
{ 
	try 
	{ 
		inputStream.close(); 
		serialPort.close();	 
	} 
	catch (IOException e) {} 
} 
 
public synchronized void removeBarCodeListener(BarCodeListener b)  
{ 
	listeners.remove(b);	 
} 
/** 
 * Captures input from the Serial Port. 
 * @param javax.comm.SerialPortEvent the input data 
 */ 
public void serialEvent(javax.comm.SerialPortEvent e)  
{ 
		if (e.getEventType() == SerialPortEvent.DATA_AVAILABLE) 
		{ 
			try 
			{ 
				// Create a buffer to read in the data 
				byte[] buffer = new byte[BUFFER_SIZE]; 
 
				// If a partial barcode was read, return so the buffer will be filled with the entire barcode information 
				// (longer barcode strings will sometimes fire 2 events with partial data in each) 
				if (inputStream.available() < length) 
					return; 
					 
				// read in the barcode information 
				while (inputStream.available() > 0) 
				{ 
						inputStream.read(buffer); 
						break; 
				} 
				 
				barCodeString = new String(buffer, 0, length); 
 
				BarCodeThread b = new BarCodeThread(listeners, barCodeString); 
				Thread t = new Thread(b); 
				t.start(); 
			} 
			catch (IOException ex)  
			{ 
				System.err.println("Error in barcode"); 
			} 
		} 
 
} 
}