This page contains an archived post to the Java Answers Forum made prior to February 25, 2002. If you wish to participate in discussions, please visit the new Artima Forums.

Message:

vonStefan:Ich hab diese Seite gefunden:

Posted by Michi on January 04, 2002 at 10:41 AM

> > /* Currently, I am working on controlling IBM Parallel Port using */
> > /* Java Communication API. And i faced a few problems and wish */
> > /* can get help as soon as possible. All helps are highly appreciated. */

> > DOSone.writeByte(0x90); ------- Statement 1
> > When the LED attached with parallel port are connected with the computer, Data Pin 3,4,5,6,7,8
> > are lighted. Although i tried to change to different values, same results are obtained.
> > May I know why this happened? and any solution?

> > System.out.println("You have come here."); ------Statement 2
> > After the LED is lighted, the Java program does not return back to DOS mode and print out
> > the above sentence. Can i make hypotheses that Java are platform independent, that's why
> > there is no way to return to Windows Dos mode? Or any solution available?

> > The source code is obtained from http://www.geocrawler.com/archives/3/196/1999/8/50/2586646/ and some slight modification is done
> > /* modified by cclee */
> > /* date: 23.08.2001 */
> > /* Platform : Windows 98 & JDK1.2 */

> > import javax.comm.*;
> > import javax.comm.ParallelPort;
> > import java.util.*;
> > import java.lang.*;
> > import java.io.*;

> > public class TestApp
> > {
> > static CommPortIdentifier CPIone;
> > static Enumeration Eone;
> > static ParallelPort Pone;
> > static OutputStream OSone;
> > static DataOutputStream DOSone;
> > public static void main (String arg[])
> > {
> > Eone=CommPortIdentifier.getPortIdentifiers();
> > while(Eone.hasMoreElements())
> > {
> > CPIone=(CommPortIdentifier)Eone.nextElement();
> > if((CPIone.getPortType()==CommPortIdentifier.PORT_PARALLEL)&&((CPIone.getName()).compareTo("LPT1")==0))
> > {
> > try
> > {
> > Pone=(ParallelPort)CPIone.open("TestApp",3000);
> > }catch(PortInUseException e){}
> > System.out.println(CPIone.getCurrentOwner());
> >
> > System.out.println(Pone.getMode());
> > System.out.println(CPIone.getPortType());
> > try
> > {
> > Pone.setMode(1);
> > }catch(UnsupportedCommOperationException e)
> > {
> > System.out.println("Unsupported byte mode.");
> > }
> > System.out.println("unidirectional");
> > }
> > }
> > try
> > {
> > OSone=Pone.getOutputStream();
> > DOSone = new DataOutputStream(OSone);
> >
> > /*where to send the data to the printer port */
> > DOSone.writeByte(0x90); ------- Statement 1
> > System.out.println("You have come here."); ------Statement 2
> > }
> > catch(IOException e)
> > {
> > System.out.println("You are in IOexception");
> > e.printStackTrace();
> > }
> > }
> > }

>
> >
> > Below are the circuit that i used for my testing

> >

> >