Java

8-Jan-10 0:13

Hello Friends
I am reading a file using BufferedReader.But I am not able to find end of file in that.Whenever If blank line appears the code that i m using
bufferedReader.readLine() returns "".and for end of file also same.how do I find End Of File.

Any Ideas??

Thanks & Regards
Yogesh Sikri

David Skelly8-Jan-10 1:40

David Skelly

8-Jan-10 1:40

BufferedReader should return null when you reach the end of the file. It sounds very odd that you are getting an empty String. Can you post a snippet of code to show how you are using the BufferedReader.

Richard MacCutchan8-Jan-10 5:12

8-Jan-10 5:12

I just tried this:

BufferedReader in = new BufferedReader(new FileReader("test.txt"));
String str;
while ((str = in.readLine()) != null)
{
	System.out.format("%s%n", str);
}
in.close();

and it works correctly, returns empty string for blank line, and null for EOF. Can you show your code?

002comp10-Jan-10 19:32

10-Jan-10 19:32

I am using like this:

temp = bufferedReader.readLine();
if(temp==null)

The only difference is that u are directly using in while loop amd i assigning variable.

When I did like u did then its working for me.Thx for ur Help.

Regards
Yogesh

Richard MacCutchan10-Jan-10 23:20

10-Jan-10 23:20

yogeshs wrote:
The only difference is that u are directly using in while loop amd i assigning variable.

This makes no difference; I tried it with assigning to a variable and it works just the same. There must be something else wrong with your code.

002comp10-Jan-10 23:58

[Solved]Fatal Exception occured when running jar file [modified]

10-Jan-10 23:58

May b or not.But now it is working.
Anyway,thx for ur help.

Jordanwb7-Jan-10 3:17

7-Jan-10 3:17

I'm writing a program using BlueJ. I created a jar file and set the Main class to the desired class. When I run the jar in Explorer I get an error window saying "Java Virtual Machine Launcher. Fatal Exception occured. Program will exit." I have a Main method which instantiates a class which extends JFrame. I wrapped that in a try-catch block to see if there was an error on my code. The message still appears. Is there a way to get a more verbose error?

*Edit*

Okay I ran it on my linux machine and this is the error:

jordanwb@jordanwb-laptop:/media/DEFB-0C36/PhpDesigner$ java PhpDesigner.jar
Exception in thread "main" java.lang.NoClassDefFoundError: PhpDesigner/jar
Caused by: java.lang.ClassNotFoundException: PhpDesigner.jar
	at java.net.URLClassLoader$1.run(URLClassLoader.java:200)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.net.URLClassLoader.findClass(URLClassLoader.java:188)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:307)
	at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:252)
	at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:320)
Could not find the main class: PhpDesigner.jar.  Program will exit.

So it can't fine the class, but how do I go about fixing that? Apparently the compiler and BlueJ can find the MainWindow class but the virtual machine can't.

modified on Thursday, January 7, 2010 4:16 PM

Richard MacCutchan7-Jan-10 4:52

7-Jan-10 4:52

Jordanwb wrote:
jordanwb@jordanwb-laptop:/media/DEFB-0C36/PhpDesigner$ java PhpDesigner.jar

I think that should be:

java -jar PhpDesigner.jar

Jordanwb7-Jan-10 7:16

7-Jan-10 7:16

jordanwb@jordanwb-laptop:/media/DEFB-0C36/PhpDesigner$ java -jar PhpDesigner.jar 
Exception in thread "main" java.lang.NoSuchMethodError: main

The main method does exist in the startup class. Confused | :confused:

import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
import java.util.*;

public class MainWindow extends JFrame implements ActionListener
{
    private JMenuBar main_menu;
    
    private JMenu file_menu;
    private JMenuItem new_project, open_project, save_project, save_project_as, quit;
    
    private JMenu objects_menu;
    private JMenuItem add_folder, add_file, add_class, add_interface, add_function, add_parameter, add_field;
    
    private JPanel php_object_manager;
    
    public MainWindow()
    {
        super ("PhpDesigner");
        
        this.setSize (800, 600);
        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        
        /* Set up main menu */
        /* Set up file menu */
        this.new_project = new JMenuItem("New Project", new ImageIcon ("./Images/document-new.png"));
        this.new_project.addActionListener (this);
        
        this.open_project = new JMenuItem("Open Project", new ImageIcon ("./Images/document-open.png"));
        this.open_project.addActionListener (this);
        
        this.save_project = new JMenuItem("Save Project", new ImageIcon ("./Images/document-save.png"));
        this.save_project.addActionListener (this);
        
        this.save_project_as = new JMenuItem("Save Project As", new ImageIcon ("./Images/document-save-as.png"));
        this.save_project_as.addActionListener (this);
        
        this.quit = new JMenuItem("Quit", new ImageIcon ("./Images/system-log-out.png"));
        this.quit.addActionListener (this);
        
        this.file_menu = new JMenu ("File");
        this.file_menu.add (this.new_project);
        this.file_menu.addSeparator();
        this.file_menu.add (this.open_project);
        this.file_menu.add (this.save_project);
        this.file_menu.add (this.save_project_as);
        this.file_menu.addSeparator();
        this.file_menu.add (this.quit);
        
        this.main_menu = new JMenuBar ();
        this.main_menu.add (this.file_menu);
        
        this.getContentPane().add (this.main_menu, BorderLayout.NORTH);
        /* End of setting up file menu */
        /* Set up Objects menu */
        
        this.add_folder = new JMenuItem ("Add Folder");
        this.add_file = new JMenuItem ("Add File");
        this.add_class = new JMenuItem ("Add Class");
        this.add_interface = new JMenuItem ("Add Interface");
        this.add_function = new JMenuItem ("Add Function");
        this.add_parameter = new JMenuItem ("Add Parameter");
        this.add_field = new JMenuItem ("Add Field");
        
        this.objects_menu = new JMenu ("Objects");
        this.objects_menu.add (this.add_folder);
        this.objects_menu.add (this.add_file);
        this.objects_menu.add (this.add_class);
        this.objects_menu.add (this.add_interface);
        this.objects_menu.add (this.add_function);
        this.objects_menu.add (this.add_parameter);
        
        this.main_menu.add (this.objects_menu);
        /* End of setting up objects menu */
        /* End of setting up main menu */
                
        this.setVisible (true);
    }
    
    public void actionPerformed(ActionEvent e)
    {
        Object source = e.getSource ();
        
        if (source == this.new_project) {  }
        else if (source == this.save_project) {  }
        else if (source == this.save_project_as) {  }
        else if (source == this.quit)
        {
            System.exit(0);
        }
    }
    
    public static void main ()
    {
        new MainWindow ();
    }
}

Richard MacCutchan7-Jan-10 9:01

7-Jan-10 9:01

How did you create your 'jar'; did you use a correct manifest file to identify the class containing the main() method?

Jordanwb7-Jan-10 9:32

7-Jan-10 9:32

I used BlueJ to create the jar which I believe creates the manifest file for me.

Richard MacCutchan7-Jan-10 9:40

7-Jan-10 9:40

Jordanwb wrote:
I used BlueJ

I'm afraid I know nothing about BlueJ so you need to go to the documentation to check it out. Alternatively you could deconstruct the jar file and check the files yourself.

Jordanwb7-Jan-10 9:53

7-Jan-10 9:53

This is the content of the manifest file:

Main-Class:MainWindow

Richard MacCutchan7-Jan-10 10:03

7-Jan-10 10:03

Sorry, that looks OK, I'm not sure what else to suggest.

Jordanwb7-Jan-10 10:11

7-Jan-10 10:11

I added String[] args to the args of main () and it works.

Richard MacCutchan7-Jan-10 23:33

7-Jan-10 23:33

Interesting; I actually wondered about that yesterday, but did not bother to test it out.

To paraphrase Sherlock Holmes: "When you have eliminated the impossible, whatever remains, however improbable, must be the answer".

Jordanwb8-Jan-10 2:49

8-Jan-10 2:49

It sortof makes sense. Java apps are capable of processing arguments, altough they're infrequently used on Windows. Another thing I forgot was that the first letter of a method is always lowercase. I had to rename Main (String[]) to main (String[]).

Richard MacCutchan8-Jan-10 4:31

8-Jan-10 4:31

Jordanwb wrote:
It sortof makes sense.

As with most things in IT. Wink | ;)

Jordanwb8-Jan-10 4:34

8-Jan-10 4:34

I had upgraded QuickBooks 2009 to 2010 edition for my dad. The conversion started off at taking four hours, then down t 2 and a half hours, down to twelve minutes then down to 3. The whole process took around 2 minutes.

Richard MacCutchan8-Jan-10 4:56

8-Jan-10 4:56

Umm, I think maybe this belongs to an alternative thread. Confused | :confused:

MouseZoom

002comp6-Jan-10 19:13

6-Jan-10 19:13

Hello Friends
I m using MouseZoom in my application and it is zoooming fine but when I zoom Out with mouse wheel then after zooming up to a certain point the image becomes invisible and then I have to again zoomin then it comes in.I dont want to make that image invisible when i do zoom out.

Do u have any Ideas?
Thanks & Regards
Yogesh

req coding in java

thileebandr4-Jan-10 23:25

thileebandr

4-Jan-10 23:25

please mail the java coding for Packet Scheduler with Packetized Ordered Round Robin Scheduling

Re: req coding in java

Richard MacCutchan4-Jan-10 23:31

4-Jan-10 23:31

thileebandr wrote:
please mail the java coding ...

That's not the way it works here. Show us what you have tried and what is not working, and people will try and help. If you want someone to do your work for you then try the Jobs forum.

Some exception Problem

002comp4-Jan-10 22:27