Page 47 - The Definitive Guide to Building Java Robots

Preston_5564C02.fm Page 28 Wednesday, September 14, 2005 5:42 AM

28 CHAPTER 2 ■ SERIAL COMMUNICATION

Example 2-5. SingleSerialPort.Java
package com.scottpreston.javarobot.chapter2;

import java.util.Vector;

private static Vector portsInUse = new Vector();

private SingleSerialPort() {
// prevents initialization
}

public static StandardSerialPort getInstance(int comid) throws Exception {
return getInstance(comid,9600);
}

public static StandardSerialPort getInstance(int comid, int baud) ➥
throws Exception {

StandardSerialPort instance = null;
String tmpComID = new Integer(comid).toString();

// return a port in use if it exist.
for (int i=0; i< portsInUse.size(); i++) {
StandardSerialPort aPort = (StandardSerialPort)portsInUse.get(i);
if (aPort.getName().endsWith(tmpComID)) {
return aPort;
}
}
// otherwise create the port if its in the list
if (instance == null) {
instance = new StandardSerialPort(comid,baud);
portsInUse.add(instance);
}
return instance;
}

public static void close(int comid) {

String tmpComID = new Integer(comid).toString();