Hari Mohanan

hello there to fellow java developers. I have developed a simple text editor which edits ".txt" files. Now I want help from the veterans in improvising the code or adding few beneficial features. You can check it out here:

http://sourceforge.net/projects/hivemindtexted/

Its nothing to brag about, but i am really a beginner. Suggestions are welcome at:

[email protected]

Thanks!

Thanks a lot for clearing my doubt, but can you tell me how to pass the reference?

what i am trying to say it, can i use the same JFrame (frame) as common for both the classes without defining a new one..

I am a beginner in java. So I have a small doubt....compare these two classes:

Marks Analysis class

import javax.swing.* ; import java.awt.* ; import java.awt.event.*; import javax.swing.border.*; public class MarkAnalysis implements ActionListener{ JFrame frame = new JFrame("::Marks Analysis::") ; JLabel loginLabel = new JLabel("Enter the security PIN Number:: ") ; JTextField field = new JTextField(4) ; JPanel login = new JPanel() ; JPanel markan = new JPanel() ; Font f = new Font("segoi ui", Font.BOLD, 14) ; JLabel mainLabel = new JLabel("Welcome to Marks Analysis!") ; public void DoTheMagic() { frame.getContentPane().add(BorderLayout.WEST, login) ; frame.getContentPane().add(BorderLayout.NORTH, markan) ; field.addActionListener(this) ; login.add(loginLabel) ; login.add(field) ; login.setBackground(Color.gray) ; markan.setBackground(Color.white) ; markan.add(mainLabel) ; mainLabel.setFont(f) ; mainLabel.setBorder(BorderFactory.createEtchedBorder(10, Color.BLACK, Color.gray)) ; frame.setSize(400,300) ; frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE) ; frame.setVisible(true) ; field.requestFocus() ; } public void actionPerformed(ActionEvent ev) { int n = 0 ; String sn = field.getText() ; try{ n = Integer.parseInt(sn) ; } catch(Exception e){ e.printStackTrace() ; JOptionPane.showMessageDialog(null, "Please enter numerals!", "Error!", JOptionPane.ERROR_MESSAGE) ; } if(n == 6973) JOptionPane.showMessageDialog(null, "Authenticating...success!", "Loggin in...", JOptionPane.INFORMATION_MESSAGE) ; else JOptionPane.showMessageDialog(null, "Authenticating...invalid PIN!", "Logging in...", JOptionPane.INFORMATION_MESSAGE) ; } }

Marks Pages class

import javax.swing.*; import java.awt.*; import java.awt.event.*; public class MarkPages ActionListener { }


Now my doubt is, if I inherit MarkPages from MarkAnalysis, can I modify the values of the JFrame 'frame'? That is, the components in the previous class will not be used, instead I only give a new form to the existing JFrame 'frame'. According to my knowledge, 'frame' is an object of class JFrame. So can an object's state be inherited? (Sorry for using confusing sentences, i am a newbie)

Guys!!! I made a very very silly mistake!!!

The part i went wrong in was executing it as :

java Test.class

The .class part was not necessary. I just had to write java Test, and voila I got an 800*600 window!

Thanks a lot...You guys gave me the best help. I'll keep troubling you guys though, cause i am still a novice.

Thanks again.

Ulf Dittmer wrote:Try compiling both in one go: "javac *.java". That will compile all Java files in the current directory.

It worked: i compiled it together

But the trouble is at execution time now----

C:\Documents and Settings\Mohan>java Test.class
Exception in thread "main" java.lang.NoClassDefFoundError: Test/class
Caused by: java.lang.ClassNotFoundException: Test.class
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
Could not find the main class: Test.class. Program will exit.

C:\Documents and Settings\Mohan>

The files are in the same folder. I have tried this before while i was coding a calculator program. There was no problem then. The only change I made was install the newer version of java sdk.

hey guys, i am a newbie in java. While compiling this code(which i wrote to test whether swing's JFrame was working or not so as to add more components) I encountered an error:

Here's the code:
Test class code
public class Test { public static void main(String [] args) { MarkAnalysis marks = new MarkAnalysis() ; marks.DoTheMagic() ; } }

MarkAnalysis class code
import javax.swing.* ; import java.awt.* ; public class MarkAnalysis { public void DoTheMagic() { JFrame frame = new JFrame("::Marks Analysis::") ; frame.setSize(800,600) ; frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE) ; frame.setVisible(true) ; } }

The error message was :

Microsoft Windows XP [Version 5.1.2600]
(C) Copyright 1985-2001 Microsoft Corp.

C:\Documents and Settings\Mohan>javac Test.java
Test.java:5: cannot find symbol
symbol : class MarkAnalysis
location: class Test
MarkAnalysis marks = new MarkAnalysis() ;
^
Test.java:5: cannot find symbol
symbol : class MarkAnalysis
location: class Test
MarkAnalysis marks = new MarkAnalysis() ;
^
2 errors

C:\Documents and Settings\Mohan>

Please help me. I am using Windows XP.