Discovering available comm ports

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Revision as of 15:03, 10 July 2007 (view source) 203.140.182.1 (Talk) (x8aba60) ← Older edit		Latest revision as of 01:23, 10 July 2009 (view source) TrbocCacel (Talk | contribs)
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-	<a href="http://e46ea4.com">1025f3</a> | [url=http://cb4c8b.com]cc97f3[/url] | [link=http://3c8010.com]31f652[/link] | http://1f0341.com | 5d8eb3 | [http://cf85b8.com 03d710]	+	http://www.textraccale.com
		+	This code snippet shows how to retrieve the available comms ports on your computer. A CommPort is available if it is not being used by another application. Note the difference between the two examples is that the version for JDK 5.0 up uses [http://java.sun.com/j2se/1.5.0/docs/guide/language/generics.html generics]:
		+
		+	<b>JDK <= 1.4</b>
		+	<pre>
		+	/**
		+	* @return    A HashSet containing the CommPortIdentifier for all serial ports that are not currently being used.
		+	*/
		+	public static HashSet getAvailableSerialPorts() {
		+	HashSet h = new HashSet();
		+	Enumeration thePorts = CommPortIdentifier.getPortIdentifiers();
		+	while (thePorts.hasMoreElements()) {
		+	CommPortIdentifier com = (CommPortIdentifier) thePorts.nextElement();
		+	switch (com.getPortType()) {
		+	case CommPortIdentifier.PORT_SERIAL:
		+	try {
		+	CommPort thePort = com.open("CommUtil", 50);
		+	thePort.close();
		+	h.add(com);
		+	} catch (PortInUseException e) {
		+	System.out.println("Port, "  + com.getName() +  ", is in use.");
		+	} catch (Exception e) {
		+	System.err.println("Failed to open port " + com.getName());
		+	e.printStackTrace();
		+	}
		+	}
		+	}
		+	return h;
		+	}
		+	</pre>
		+
		+	<b>JDK >= 5.0</b>
		+	<pre>
		+	/**
		+	* @return    A HashSet containing the CommPortIdentifier for all serial ports that are not currently being used.
		+	*/
		+	public static HashSet<CommPortIdentifier> getAvailableSerialPorts() {
		+	HashSet<CommPortIdentifier> h = new HashSet<CommPortIdentifier>();
		+	Enumeration thePorts = CommPortIdentifier.getPortIdentifiers();
		+	while (thePorts.hasMoreElements()) {
		+	CommPortIdentifier com = (CommPortIdentifier) thePorts.nextElement();
		+	switch (com.getPortType()) {
		+	case CommPortIdentifier.PORT_SERIAL:
		+	try {
		+	CommPort thePort = com.open("CommUtil", 50);
		+	thePort.close();
		+	h.add(com);
		+	} catch (PortInUseException e) {
		+	System.out.println("Port, "  + com.getName() + ", is in use.");
		+	} catch (Exception e) {
		+	System.err.println("Failed to open port " +  com.getName());
		+	e.printStackTrace();
		+	}
		+	}
		+	}
		+	return h;
		+	}
		+	</pre>

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Latest revision as of 01:23, 10 July 2009

http://www.textraccale.com This code snippet shows how to retrieve the available comms ports on your computer. A CommPort is available if it is not being used by another application. Note the difference between the two examples is that the version for JDK 5.0 up uses generics:

JDK <= 1.4

   /**
     * @return    A HashSet containing the CommPortIdentifier for all serial ports that are not currently being used.
     */
    public static HashSet getAvailableSerialPorts() {
        HashSet h = new HashSet();
        Enumeration thePorts = CommPortIdentifier.getPortIdentifiers();
        while (thePorts.hasMoreElements()) {
            CommPortIdentifier com = (CommPortIdentifier) thePorts.nextElement();
            switch (com.getPortType()) {
            case CommPortIdentifier.PORT_SERIAL:
                try {
                    CommPort thePort = com.open("CommUtil", 50);
                    thePort.close();
                    h.add(com);
                } catch (PortInUseException e) {
                    System.out.println("Port, "  + com.getName() +  ", is in use.");
                } catch (Exception e) {
                    System.err.println("Failed to open port " + com.getName());
                    e.printStackTrace();
                }
            }
        }
        return h;
    }

JDK >= 5.0

   /**
     * @return    A HashSet containing the CommPortIdentifier for all serial ports that are not currently being used.
     */
    public static HashSet<CommPortIdentifier> getAvailableSerialPorts() {
        HashSet<CommPortIdentifier> h = new HashSet<CommPortIdentifier>();
        Enumeration thePorts = CommPortIdentifier.getPortIdentifiers();
        while (thePorts.hasMoreElements()) {
            CommPortIdentifier com = (CommPortIdentifier) thePorts.nextElement();
            switch (com.getPortType()) {
            case CommPortIdentifier.PORT_SERIAL:
                try {
                    CommPort thePort = com.open("CommUtil", 50);
                    thePort.close();
                    h.add(com);
                } catch (PortInUseException e) {
                    System.out.println("Port, "  + com.getName() + ", is in use.");
                } catch (Exception e) {
                    System.err.println("Failed to open port " +  com.getName());
                    e.printStackTrace();
                }
            }
        }
        return h;
    }