MIDP1.0 System out

I�m new at developing applications aming palm Vx (palm os 3.5.0)handheld.
I use the JavaTM 2 Platform Micro Edition Wireless Toolkit version 1.0.4_01 for Windows.
If I hotsync a complete example .prc file, it runs ok on my palm with MIDP for PalmOS v1.0.
When I compile .java source code myself and then convert the JAR/JAD files into a .prc file and runs it on my palm only a blank screen appears for aprox. 1 second.
What am I doing wrong?!?
My first goal is to create some output on screen so I have a basic understanding, i.e a System.out.println("Hello world"); is enough :-)
Can anyone give a simple sample source code for this?
Thanx, Andreas Larsson
[email protected]

HI Andreas!
I have not yet used Palm O.S. but i have designed some midlets for given devices, what i experienced is when u use:
a) System.out.pirntln() or
b) double or float operations;
it my emulator gives me "INVALID CONSTANT POOL ERROR".
I alternatively used
new Form("My Form").append(""); statement

Similar Messages

Is there a way to make system.out.println() scroll down as it goes?

I am writing a program where I want to be able to read what's printed out in the console of my IDE through System.out.println() as the program runs/after the program runs. However, right now I run the program, the message prints out, and then when I go to read it the scroll bar is all the way up so I can see only the top of the print-out (the first thing printed out). Is there any way I can get the console to scroll along with the text, kind of like floating boxes you see on various websites for various reasons? In other words, can I get it so that when I look in the console at any given moment of the program running, I am looking at the newest text printed out (the text at the bottom of the "page")? Thank you!

That would be an IDE problem and not a Java one. You could redirect output into a text file so you can read at your leisure and scroll up and down as much as you like.

Is there a way to force System.out.println to run when called

I working on my first threaded program and having a hard time debugging. I've used System.out.println to let me know what's going on but due (I assume) to the nature of threads the output is not sequential. Is there a way to force println to execute immediatly so that they show up in the order they were called?
Thanks --- Mike

mjs1138 wrote:
endasil, Thanks for the reply. I'm currenlty running the program from within the NetBeans IDE. It is the output displayed by in NetBeans "output" that I'm looking at.
--- MikeI don't use Netbeans, but I would guess that it too pipes Standard Out and Standard Error to the same console. You didn't address my comment. Are you printing to System.err as well? This happens implicitly if you use Exception.printStackTrace(), for example.

System.out not working on eclipse

Greetings...
I am no longer a newbie on Java, but I have been facing an issue lately that I have been unable to resolve myself, even though it seems to be something so silly.
I have been using eclipse for development, and by developing a simple "Just to practice" code I have found myself unable to use System class or any of its methods at a certain point. See the code below:
package one;
import java.util.Scanner;
public ClassOne {
public static void main (String args[]){
Scanner reader = new Scanner(System.in); /*Works just fine here*/
int x = 0;
System.out.println("Type in the number of objects expected"); /*Does not work at all, like if System was something I could not use at all. Not an identifier */
Scanner readertwo = new Scanner(System.in); /*System does not work here either*/
}Even if I rewrite the code after that, by erasing the import statement and all other System references in the code, System does not work again.
If anybody has ever faced the same issue and knows what I am doing wrong and what I can do to fix it, I'd really be grateful.
Thanks to all, and happy 2009.
Santana T

Santana_Thiago wrote:
It works on NetBeans.
On eclipse I get the following error:
ERROR: JDWP Unable to get JNI 1.2 Environment, jvm->GetEnv() return code = -2+
*JDWP exit error AGENT_ERROR_NO_JNI_ENV(183): [../../../src/share/back/util.c:820]*+
The funniest thing is that if copy and paste the code from somewhere else into eclipse it works. What a drag!!!!
Thank you.
Santana TNever seen that error but it sounds to me that your Eclipse installation is screwed up!

32-bit JDK 7 System.out.println not working in IDE

Hi folks,
I have a 64-bit Windows 7 OS.
Due to 3rd party library/jar dependencies, i had to install the 32-bit Java JDK 1.7 and Eclipse IDE.
I also installed NetBeans.
So i have a 64-bit OS and am running 32-bit Java JDK/JRE & IDEs.
The problem I am having is that my program's System.out.println("...") statements are not outputting strings to either IDE debug console.
Executing the compiled program from a command line/prompt produces the expected string output.
The basic "Hello, World" program is enough to cause this behaviour to start occurring.
I have not manually / intentionally changed any IDE-specific Debug Console or Windows environment settings.
One caveat: This same environment has worked successfully in the past ?! Yes, this is one of those "..it worked last week & yesterday and today it isn't and i swear i didn't do anything..." issue.
Thoughts ?

Thanks for the reply.
The 64-bit versions of Java & Eclipse were installed first.
When i discovered I had to use the 32-bit versions, i un-installed the 64-bit ones & installed the 32-bits.
Even after that initial un-install 64-bit/install 32-bit process, it was working.
I have also been installing the Windows 7 64-bit OS updates when i am informed of them.
I'm not sure if any of these would affect how the Eclipse / NetBeans IDEs behave.
Behaviour has been inconsistent.
Initially it was always working.
But over the past several days, it has been working less and less.
I don't have any large data structures.
This isn't a large complicated program, couple hundred lines, so i highly doubt that i'm doing anything to the resources, but something has changed.
The main project I am working on takes command line parameters, does some initial processing, produces output using System.out.printlns [SOP] then depending on the parameters, branches into 2 different processing paths, let's call them A & B. Each of these processing paths also use SOPs. When i run the program in the IDE going thru path A, sometimes the initial SOP statements will work and the SOP statements specific to path A will also work. If i immediately change the parameters to go thru path B & re-run it, not even the initial SOP statements before the branching decision work.
I've tried doing System.flush()s too - no affect.
I haven't tried the re-direction option to a file option you mentioned yet.
It always works from a command prompt - that is telling me that the Java SOPs are working properly, correct ?
Inside an Eclipse or NetBeans IDE, SOP output to the debug console is inconsistent.
Running from a command prompt, the SOPs always work.
It'd help to know if this an IDE issue, a Java issue, a Windows 7 issue so i can narrow down where to try and correct the situation.
I have a Windows XP VM set up, i'll try running the program there and see if there's a difference.
Thanks for your reply.

How can i put a system.out.println into txt file

i want to generate a txt file instead of system.out.println. for the output How can i do that and what code can i use for that??
Edited by: crystalarun on Oct 14, 2007 11:40 AM

suppose u ant output in "Output.txt"
then code can be
PrintStream out = new PrintStream(new FileOutputStream("Output.txt"));
System.setOut(out)

System.out.println () is not working properly

Hi, Why does this happens:
Object temp=null;
System.out.println ("temp is null? "+temp==null);
just prints: true
expected: temp is null? true
Why does this happens????
If I do System.out.println ("temp is null? "+(temp==null)); it works bu it should work without the pharentesis too

MelGohan wrote:
Hi, Why does this happens:
Object temp=null;
System.out.println ("temp is null? "+temp==null);
just prints: trueThat is odd, mine prints "false".
type Test126.java
public class Test126 {
    public static void main(String[] args) {
        Object temp=null;
        System.out.println ("temp is null? "+temp);
        System.out.println ("temp is null? "+temp==null);
}javac Test126.java
java Test126
temp is null? null
false

System.out.println in Web Dynpro Java

I call System.out.println in some components in web dynpro java. But I cannot find the standard console output file of SAP J2EE Engine. Anyone know where is the location of standard output file?

Thanks Deepak. Your link blog is working.
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Edited by: Nuttakorn Boonthamtanarung on Apr 1, 2010 6:58 AM

Can you listen to System.out ?

Good morning form. Is there a way to listen to System.out?
This could be useful in testing. You could compile a test version of the app and report all Sys out activity then turn it of in production (or not). The point would be to be able to apply this to applications after they were written. (as in not a consideration at the time the app was written).
I know if the app is run from a command line you can pipe the output to a file.
Thanks
ST

Good morning form. Is there a way to listen to
System.out?
This could be useful in testing. You could compile a
test version of the app and report all Sys out
activity then turn it of in production (or not). The
point would be to be able to apply this to
applications after they were written. (as in not a
consideration at the time the app was written).
I know if the app is run from a command line you can
pipe the output to a file.
Thanks
STHi, you should use logging instead. E.g. Log4J or java.util.logging

Parse RSS feed -System.out

Hi,
As below i have been reading RSS feeds.
When i execute the parser.parse(url) method i get a dump of the xml bones from the feed onto System.out, which in my case is a catalina log file.
Is there any way/method that im not aware of that can prevent this going to System.out?
public void readRSSDocument() throws Exception {
        //Create the parser
        RssParser parser = RssParserFactory.createDefault();
        //Parse our url
        Rss rss = parser.parse(
                new URL("http://rss.cnn.com/rss/cnn_world.rss"));
    }output:
<rss>
<channel>
<title>
</title>
<link>
</link>
<description>
</description>
<language>
</language>
<copyright>
</copyright>
<pubDate>
</pubDate>
<ttl>
</ttl>
<image>
<title>
</title>
<link>
</link>
<url>
</url>
<width>
</width>
<height>
</height>
<description>
</description>
</image>
<atom10:link>
</atom10:link>
<atom10:link>
</atom10:link>
<item>
<title>
</title>
<guid>
</guid>
<link>
</link>
<description>
</description>
<pubDate>
</pubDate>
<feedburner:origLink>
</feedburner:origLink>
</item>
<item>
<title>
</title>
<guid>
</guid>
<link>
</link>
<description>
</description>
<pubDate>
..

I am presuming that you picked up the code from [this tutorial|http://java.sun.com/developer/technicalArticles/javaserverpages/rss_utilities/]
Looks like the library was compiled with System.out.println() statements in it.
There is always the handy little method "System.setOut()" to redirect it.
Alternatively, decompile the code, delete/comment the System.out.println statements and then recompile it.
Its not that hard. Here's the offending class:
// Decompiled by Jad v1.5.8g. Copyright 2001 Pavel Kouznetsov.
// Jad home page: http://www.kpdus.com/jad.html
// Decompiler options: packimports(3)
// Source File Name:   DocumentHandler.java
package com.sun.cnpi.rss.handlers;
import com.sun.cnpi.rss.elements.Element;
import com.sun.cnpi.rss.elements.Rss;
import java.io.PrintStream;
import java.util.*;
import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;
// Referenced classes of package com.sun.cnpi.rss.handlers:
//            NullElementHandler, ElementHandler, HandlerException
public class DocumentHandler extends DefaultHandler
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        handlers = new HashMap();
        handlerStack = new Stack();
        parentStack = new Stack();
        rss = new Rss("rss");
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        parentStack.add(rss);
    public void registerHandler(String key, ElementHandler handler)
        handlers.put(key.toLowerCase(), handler);
    public void addToParentStack(Element parent)
        parentStack.add(parent);
    public Element popFromParentStack()
        return (Element)parentStack.pop();
    public Element peekParentStack()
        return (Element)parentStack.peek();
    public void startElement(String uri, String localName, String qName, Attributes attributes)
        throws SAXException
        //System.out.println("<" + qName + ">");
        try
            ElementHandler currentHandler = (ElementHandler)handlers.get(qName.toLowerCase());
            handlerStack.add(currentHandler);
            if(currentHandler != null)
                Element parent = (Element)parentStack.peek();
                currentHandler.startElement(this, parent, uri, localName, qName, attributes);
        catch(HandlerException e)
            e.printStackTrace();
        super.startElement(uri, localName, qName, attributes);
    public void characters(char ch[], int start, int length)
        throws SAXException
        StringBuffer buffer = new StringBuffer();
        Element element = (Element)parentStack.peek();
        if(element.getText() != null)
            buffer.append(element.getText());
        buffer.append(ch, start, length);
        element.setText(buffer.toString());
        super.characters(ch, start, length);
    public void endElement(String uri, String localName, String qName)
        throws SAXException
        //System.out.println("</" + qName + ">");
        if(!handlerStack.isEmpty())
            try
                ElementHandler currentHandler = (ElementHandler)handlerStack.pop();
                if(currentHandler != null)
                    Element parent = (Element)parentStack.peek();
                    currentHandler.endElement(this, parent, uri, localName, qName);
            catch(HandlerException e)
                e.printStackTrace();
        super.endElement(uri, localName, qName);
    public Rss getRss()
        return rss;
    private Map handlers;
    private Stack handlerStack;
    private Stack parentStack;
    private Rss rss;
}

How to capture System.out, done by another program

Hi All,
My application runs other application in back. How can I capture system.out.println() written by another application & display via dialog box.
Like :execl() or execv() function in C runtime library. Where every printf() message printed to passed buffer.
Thank you,
Avin Patel

You can create an InputStream from a started process. Then read all the bytes from the inputstream and write them to an outputstream (like System.out)
Process p = Runtime.getRuntime().exec(COMMAND);
InputStream is = p.getErrorStream(); //Or another stream
int[] buffer = new int[128];
while((read = is.read(buffer)) != -1){
System.write.out(buffer, 0, read);
}

How to capture System.err and System.out in a method?

Is there some way to capture everything that is sent to System.err or System.out and have it instead go to e.g. a method as a String?
The reason I want to do is this: I am invoking some method from a class that sends output to System.err and System.out but while that method is run, I want everything that goes to System.out or System.err to instead go to a String buffer or a Swing Scroll Pane.
What is the easiest way to do this?

I want everything that goes to System.out or System.err to instead go to a String buffer or a Swing Scroll Pane.Then maybe you should be searching (and then posting) in the Swing forum. Thats where I've seen this question asked and answered many times in the past.

JDK 1.6_07 with Windows: System.out.flush() does not work...

I wonder if this is a known issue: Since I upgrade the jdk1.6 version to the _07 pack, text IO does not work anymore with WinXP cmd.exe window. Assuming a static import of System.out, I use:
static void prompt()
out.print(pr); //pr is a prompt string...
out.flush();
}works as usual with Unix/Linux, but with windows nothing will be written to the terminal, until I make at least one input. In that case a barrage of cached prompts appear all at once.
Do we have a bug for it, can we work around somehow?
Thomas

Since this code works correctly in Java 6u10 on Windows XP
System.out.print("This is the data");
System.out.flush();You are apparently doing something unusual or wrong. What is "out"?
Show a small sample program that compiles and exhibits the problem when executed.

System.out.println not working in Tomcat-4.1.x

System.out.println not working in Tomcat-4.1.24. Any settings has to be enabled??? I am using tomcat for Solaris

I think u can use ServletContext.log() to output info instased.

Redirecting system.out to a file

I want to have the output of these threads go to a file, which it is doing now, but the program is finishing before all the data is written to the file.
I had another idea that the threads could write to a shared stringbuffer and then when they have finished, i could write the contents of that stringbuffer to a file, but when do it tell it to write to the file. how can i tell when the threads are finished.
/*      12 Nov 2002
     Class extends PThread which extends Thread.
import Concurrency.*;
import java.io.*; //added to write output to a file
public class Exercise1 extends PThread{
     private static File theOutputFile;
     private static FileWriter fileWriterStream;
     private static int counter = 0;
     public Exercise1() {
          try {
               if(theOutputFile == null) {
                    theOutputFile = new File("output.txt");
                    fileWriterStream = new FileWriter(theOutputFile);
          }catch(IOException ioe){}
     public static void main(String[] args) throws IOException {
          System.out.println("Dave Casserly\n" +
                                   "Check the source folder for a file called output.txt\n" +
                                   "This contains the programs output.\n");
          Exercise1 thread1 = new Exercise1();
          Exercise1 thread2 = new Exercise1();
          thread1.start();
          thread2.start();
     //each thread will look at counter make sure its less than 1000,
     //get the current counter value and increment it
     //print it to screen
     //then increment the static counter
     public void run(){
          try {
               while(counter <= 1000) {
                    int count = counter;
                    count++;
                    counter++;
                    System.out.println("COUNT = " + count);                    //write to screen
                    fileWriterStream.write("COUNT = " + count + "\n");      //write to file
                    counter = count;
          }catch(IOException io){}
}//end of class

You need to join the main thread with the child threads.
Something like this:
Exercise1 thread1 = new Exercise1();
Exercise1 thread2 = new Exercise1();
thread1.start();
thread2.start();
thread2.join();
thread1.join();Or something.

MIDP1.0 System out

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