How do I redirect System.err output in iPlanet 4.1?

All,
I've been trying for days to redirect System.err output from a Java program
to a log file. I followed the instructions here:
http://knowledgebase.iplanet.com/ikb/kb/articles/4790.html
Unfortunately, nothing has been written to any of the log files (even though
I have plenty of System.err.println()'s in my code).
Anyone else get this to work correctly?
Thanks in advance,
--Bill

Hi,
What is the product web server or application server ? If it is application
server then I'm very sure that this output will be seen in the kjs log file in
Unix and in the command window in Windows NT/2K, only if you have allowed the
process to interact with desktop. Please let me know if this answers your
question for me to help you further on this.
Regards
Raj
"news.uswest.net" wrote:
All,
I've been trying for days to redirect System.err output from a Java program
to a log file. I followed the instructions here:
http://knowledgebase.iplanet.com/ikb/kb/articles/4790.html
Unfortunately, nothing has been written to any of the log files (even though
I have plenty of System.err.println()'s in my code).
Anyone else get this to work correctly?
Thanks in advance,
--Bill

Similar Messages

How do I redirect System.err msg on NT

As you probably already know, when running a standard alone java program, say myapp.class, if one wants to redirect the System.out.println message, one might do this on NT dos prompt:
java myapp > myout.txt
In this case, all messages from System.out.println that suppose to print on the screen are redirected to be written into myout.txt.
If your error messages are displayed using System.err.println, the same command does not save your message to the file redirected as above. Does anyone know how can I do some similar thing in the command line to redirect my error messages into a file?
Thanks for help.
Stan

to redirect standard error on nt:
java myapp 2> myout.txt

How redirect System.err ?

Hi,
I'm debbuging on device and I would like to change the System.err value to redirect its outputs.
I have some log methods to write common outputs in a text file on the device, and I need to check the output of the mehtod Exception.printStackTrace().
How can I redirect System.err ??
Thanks in advance,

Well, as a matter of fact, CLDC/MIDP specifications (this is CLDC and MIDP forum JFYI) do not provide means for application to get printStackTrace output anyhere else but System.err.
You can not change that fact, no matter how you try. Oh and this is a verifiable fact - anyone can get mentioned specifications and check if it's true.
I would also add that per my reading of above specifications, compliant device even "has a right" to simply swallow anything that goes to System.err - including the output of printStackTrace.
I mean, specs allow devices where trying to get output of printStackTrace is the same as trying to get something from [ /dev/null|http://en.wikipedia.org/wiki//dev/null]. Oh and by the way my conclusion is, again, verifiable - that is, anyone can get the specs and check if there's a requirement for devices not to behave that way.
Does that answer your question?

Redirecting System.err on a mobile phone?

Hi,
Is there a way of redirecting System.err? Unfortunately, System.setErr does not exist in MIDP, so I haven't been able to write my own PrintStream to replace err.
I need to know what the output of Exception.printStackTrace() is at a certain point. There is certainly a way of accessing System.err, otherwise it wouldn't be present in MIDP ... .
Thanks!
Stefan

Hi
J2ME Polish provides a logging framework, which offers different logging levels and the ability to view logging messages on real devices.
Mihai

Exceptions .. redirecting System.err

I've redirected System.err to a custom class that extends OutputStream.
I have a couple of questions which someone in here might know the answer to:
1. When I receive an exception write(byte b[], int off, int len) is called. The array of bytes is always 8192 long - padded with \x0000 at the end. Why?
2. How do I know an exception has ended? I want to notify the user when it has ended (with a popup). But write() is called for each line, and flush() doesn't seem to be called at all.
Best regards,
Bjorn

Depends what kind of a program you are writing. If you are doing a standalone application, you can always have a master try-catch block in the main() method that will catch Throwable. Nothing should make it past that.
Now, if you are doing a servlet or EJB, you don't want to trap every exception because the container is supposed to receive and handle them for you (thread death, out of memory, etc.) If you have a front-controller pattern implemented, you can put a master try-catch block there and do something like the following:
try {
// implement cool functionality here
catch (RuntimeException e) {
// use code to retrieve stack trace
throw e;
catch (Exception e) {
// use code to retrieve stack trace
// handle exception in application-specific manner
catch (Error e) {
// use code to retrieve stack trace
throw e;
The cool "feature" about exceptions is that they propogate. So, if you don't have the appropriate catch block, it will move to the previous caller. Hence, you can have a master exception processor if either a) you re-throw exceptions on to be procsesed by the master exception processor or b) you don't handle the exception at all and let it propogate naturally.
You also have a number of options so you don't have to rewrite 300 exception try-catch blocks. Subclass Exception, and for all your custom exceptions, put the functionality to dump or store the stack trace there. It will happen anytime your custom exception is instantiated.
Lots of ways to skin a digital cat. However, the argument that you will have to change code to get new functionality is part and parcel of the beast. If you want to capture the stack trace and do something with it, code somewhere will have to change. Either use inheritance, delegation or the exception propogation mechanism inherent to Java to minimize your work.
- Saish
"My karma ran over your dogma." - Anon

Redirecting System.out() output to a JTextArea control

I want to be able to redirect System.out() and System.err() messages to a JTextArea control:
I know how to redirect output to a file as follows:
FileOutputStream fos =
new FileOutputStream(filename, true);
PrintStream ps = new PrintStream(fos, true);
System.setOut(ps);
System.setErr(ps);
How can I set it up so that I can recognise when messages have been to System.out() with a view to displaying the message within the JTextArea?
I guess I need to set it up so that the JTextArea control acts as an Observer. The bit I'm having difficulty with is figuring out how I can automatically determine when information has been written to System.out()?
Hopefully I'm explaining my issue in enough detail and clarity.
thanks
- Garry

I would suggest you set up a separate thread to monitor System.out. Use a PipedOutputStream and redirect System.out to that, then connect that to a PipedInputStream that your other thread is continually waiting to read. Each time that thread reads a line, it should append the line to the JTextArea, using SwingUtilities.invokeLater.
This is just a rough outline of something that might work. Hope it helps.

Redirecting System.err to a JOptionPane

Hello,
I tried to write a piece of code which shows all exceptions in a JOptionPane instead of the console. But I meet two difficulties:
1. I don't know how to detect the line count of the error message (so that currently I have to display the optionPane for each error line, which is unacceptable).
2. I receive more error messages than expected. The produced parse error gives 5 lines on a console, but here I receive 60.
What's wrong?
import java.awt.*;
import java.awt.event.*;
import java.io.*;
import javax.swing.*;
class Redirecting extends JFrame {
public Redirecting() {
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    setSize(300,300);
    JTextAreaOutputStream err= new JTextAreaOutputStream();
    System.setErr(new PrintStream(err));
    JButton b= new JButton("Produce error");
    b.addActionListener(new ActionListener() {
      public void actionPerformed(ActionEvent evt) {
     System.out.println(Integer.parseInt("1"));
     System.out.println(Integer.parseInt("2"));
     System.out.println(Integer.parseInt("Error"));
    add(b, BorderLayout.SOUTH);
    setVisible(true);
public static void main(String[] args) throws Exception {
    EventQueue.invokeLater(new Runnable() {
      public void run() {
     new Redirecting();
class JTextAreaOutputStream extends OutputStream {
    int icnt=0;
    private JTextArea area;
    public JTextAreaOutputStream() {
      area= new JTextArea();
    public void flush() throws IOException {
      JOptionPane.showMessageDialog(Redirecting.this, area, "Error",
                              JOptionPane.ERROR_MESSAGE);
//      area.setText("");
    public void write(byte b[]) throws IOException {
      area.append(new String(b));
    public void write(byte b[], int off, int len) throws IOException {
      System.out.println(icnt++);
      String s = new String(b , off , len);
      area.append(s);
      flush(); // to make error lines visible
    public void write(int b) throws IOException {
      area.append(String.valueOf(b));
}

maybe this ?
      * recieving error for testing
      * @param e
     protected void bt_generateError_actionPerformed(ActionEvent e) {
          DateFormat fo = new SimpleDateFormat("mm.dd.yyyy");
          try {
               // Here reciev parsing error
               fo.parse("sacascsa");
          } catch (ParseException e1) {
               String exception = Util.formateException(e1.getStackTrace());
               // show error
               Util.showException(frame, exception);
      * utilita
      * @author Dima
     public static class Util {
           * formateException formating error in way you want
           * @param stack
           * @return
          public static String formateException(StackTraceElement[] stack) {
               String formatedException = "";
               for (int i = 0; i < stack.length; i++) {
                    System.err.println(stack.getClassName() + ""
                              + stack[i].getMethodName() + "" + stack[i].getClass()
                              + " Line" + stack[i].getLineNumber());
                    formatedException = formatedException.concat(
                              stack[i].getClassName()
                              + "."
                              + stack[i].getMethodName()
                              + " "
                              + stack[i].getClass()
                              /** + " Line" + stack[i].getLineNumber() */
                              + "\n"); // remove comment and recieve errors line
                                             // numbers
               return formatedException;
          * showException return JOptionPane with formatted error
          * @param com
          * @param exceptionText
          public static void showException(Component com, String exceptionText) {
               JPanel canva = new JPanel();
               canva.setMinimumSize(new Dimension(300, 200));
               canva.setPreferredSize(new Dimension(300, 200));
               JTextArea area = new JTextArea();
               area.setText(exceptionText);
               JScrollPane pan = new JScrollPane();
               pan.getViewport().setView(area);
               canva.setLayout(new BorderLayout());
               canva.add(pan);
               JOptionPane.showMessageDialog(com, canva, "Error Title",
                         JOptionPane.ERROR_MESSAGE);

Redirecting System.err to a TextArea

Hi there !
I want to redirect the output of System.err to a TextArea.
System.err is everywhere in my project. Is there any simple way to just redirect the output of this err to some TextArea?
Thanks in Advance
Dexter

See the API java.lang.System.setErr()You will then need to start a thread to read from the PrintStream and put the
output in your text area.
- ajay

Which log file contains System.err output?

If I start weblogic using startWebLogic.cmd then output sent to System.err gets
output to the console window that opens up. However, if I instead start weblogic
as a service, nothing sent to System.err gets output to the weblogic.log file.
Where does it go?

Hi there,
My message was borne of 2 days frustration out of nearly a year of smooth operations with Oracle App Server. Unfortunately I let my mouth (or fingers) run off with those frustrations and made a post that was innappropriate and un-necessary and like every bad workman I blamed my tools.
My apologies for that. Having found where the OPMN logs are stored (and it's pretty obvious to anyone who isn't seeing through a red mist!) I have now fixed my issue pretty quickly.
Thanks for your patience glin - OAS and JDev together have in this past year have served me well and as you say are in general pretty straight forward to use. (My frustration was due to J2EE ClassLoaders, they always cause me some kind of headache somewhere!)
Best Regards,
Happy Holidays!

Capture System.err

how do i capture System.err so i can do with it as i will?

on an actual phone, you dont, you use some kind of Logger, or you can use the netbeans+bluetooth+sonyericsson tools to view the system.out/system.err outputs on a live device

[Feature Request] Seperate tab in log window for System.err

By default, the stack traces of exceptions (and throwables in general) are printed to the System.err stream. So, wouldn't it be useful to include a 2nd tab for System.err messages?
It could be optional to either include or leave out the System.err output in the System.out tab.
The whole idea of this 2nd tab is to set it up like the search output tab: a tree-like list which can be expanded to see the stack trace of each exception that occured during runtime. A small parser can parse the stack trace when an exception is printed on the System.err stream and format it.
If this option would be availble in the debugger only, that would be ok too, I guess. Although, the debugger already has some other means of jumping through code when an exception is thrown (ie, when the debugger 'pauses' runtime).

I've logged an Enhancement request to improve the handling of System.err messages (2811508). There are ways to enhance the treatment of System.err messages without introducing a new tab, through the use of color, links back to the source code, and collapsing of entire stack traces to a single line (with a button to see the entire trace).
Thanks!
-- Brian

Redirecting System.out and System.err to files

Is there a way I can configure my web-appliction (in web.xml or something) to redirect all the output (.err and .out) to specific files?

I think you could create PrinStreamS from your desired output files and then use System.setOut(<...>) and System.setErr(<...>). Place this code in a servlet that you load at startup...

How do I set upmy Imac to allow using both my computer speakers and a Bose SoundLink system as outputs at the same time. I can use one or the other, but not both.

how do I set up my Imac to allow using both my computer speakers and a Bose SoundLink system as outputs at the same time. I can use one or the other, but not both. From systems Preferences I must select one or the other. I want both to work all the time.

Hi,
I would recommend you to use 0FI_AP_4 rather using both, particularly for many reasons -
1. DS: 0FI_AP_4 replaces DataSource 0FI_AP_3 and still uses the same extraction structure. For more details refer to the OSS note 410797.
2. You can run the 0FI_AP_4 independent of any other FI datasources like 0FI_AR_4 and 0FI_GL_4 or even 0FI_GL_14. For more details refer to the OSS note: 551044.
3. Map the 0FI_AP_4 to DSO: 0FIAP_O03 (or create a Z one as per your requirement).
4. Load the same to a InfoCube (0FIAP_C03).
Hope this helps.
Thanks.
Nazeer

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.

System.out and System.err How to get to show up in log

Does anyone know if there is anyway to get System.out and System.err
messages to appear in the log?
Trying to build and debug a JSP project is a complete nightmare when the
remote developers cannot see System.out or System.err messages from helper
classes.
Platform= Windows NT 4.0
Weblogic running as a Service
Thanks in advance!

Write a wrapper class to redirect the std out to what ever stream you want.
HTH
Saman

How do I redirect System.err output in iPlanet 4.1?

Similar Messages

Maybe you are looking for