COM port printer writing java example

PosPrinter.java

package app.posmachine.machine;

import java.io.IOException;
import java.io.OutputStream;
import java.util.Enumeration;

import javax.comm.CommPortIdentifier;
import javax.comm.SerialPort;

public class PosPrinter {
	public static Enumeration printport = CommPortIdentifier
			.getPortIdentifiers();

	/**
	 * This method is used to create the stream to the printer.
	 */
	public static OutputStream getStream(String port) throws Exception {
		while (printport.hasMoreElements()) {
			CommPortIdentifier portid = (CommPortIdentifier) printport
					.nextElement();
			if (portid.getPortType() == CommPortIdentifier.PORT_SERIAL) {
				if (portid.getName().equals(port)) {
					SerialPort com = (SerialPort) portid.open("ListPortClass",
							300);
					com.setSerialPortParams(9600, SerialPort.DATABITS_8,
							SerialPort.STOPBITS_1, SerialPort.PARITY_NONE);
					OutputStream output = com.getOutputStream();
					return output;
				}
			}
		}
		return null;
	}

	/**
	 * This method can be used to create a line
	 */
	public void printLine(String line, OutputStream outputStream)
			throws IOException {
		final byte[] bytes = line.getBytes("UTF-8");
		outputStream.write(bytes);
		newLine(outputStream);
	}

	/**
	 * Writes a new line in the printer
	 */
	public void newLine(OutputStream outputStream) throws IOException {
		outputStream.write(new byte[] { 10, 13 });
	}

	private static final byte PRINTER = 1;
	private static final byte DRAWER = 1;
	private static final byte DISPLAY = 2;

	/**
	 * Since the printer is connected to the customer display we need to switch
	 * between. below code is necessary for that purpose.
	 */
	public void prepareResource(OutputStream outputStream) {
		try {
			outputStream.write(new byte[] { 27, 61, PRINTER });
			outputStream.flush();
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
}