Java

Need to Confirm Creation of a Array List of Entry Objects

25-Oct-09 0:01

If you understand this then you can code it:

In mathematics, and in particular number theory, a practical number or panarithmic number is a positive integer n such that all smaller positive integers can be represented as sums of distinct divisors of n. For example, 12 is a practical number because all the numbers from 1 to 11 can be expressed as sums of its divisors 1, 2, 3, 4, and 6: as well as these divisors themselves, we have 5=3+2, 7=6+1, 8=6+2, 9=6+3, 10=6+3+1, and 11=6+3+2.
Source: Wiki[^]

Re: Practical numbers

yohoprashant7-Nov-09 5:37

yohoprashant

7-Nov-09 5:37

This link might help you.

http://wowjava.wordpress.com/2009/11/07/practical-number-in-range/[^]

srbruno24-Oct-09 15:57

srbruno

24-Oct-09 15:57

I need to know if I have successfully created a Square Matrix List of Entry Objects. The detail desciption and my java code solution follows:

A) Description
1) The List ADT will export its services to the Matrix ADT.
2) The List ADT will defines a List of Objects. The Objects referred to by these List elements will be defined in the Matrix ADT
3) The Matrix ADT, in file Matrix.java, defines the Matrix class. This class will contain a private inner class that encapsulates the column and value information corresponding to a matrix entry.

B) Code

List.java

class List
{
private class Node
{ Object obj;
Node next, prev;

// Node Constructor
Node (Object o) { this.obj = o; next = prev = null; }

// toString: Overrides object's toString method.
public String toString() { return String.valueOf(obj); }
}

// List Fields
private Node front, back, current;
private int row, length;

// List Constructor
List(int r)
{ front = back = current = null;
this.row = r; this.length = 0;
}
}

Matrix.java
class Matrix
{
private class Entry
{ int col;
double val;

// Entry Constructor
Entry (int col, double val) { this.col = col; this.val = val; }

// toString: Overrides Object's toString() method.
public String toString() { return " (" + col + ", " + val + ")"; }
}

// Matrix Fields
private List[] Entry;
private int size, nnz;

// Matrix Constructor
Matrix(int n) { Entry = new List[n]; this.size = n; nnz = 0; }
}

Re: Need to Confirm Creation of a Array List of Entry Objects

427748025-Oct-09 0:03

Adding Objects to ArrayList[^]

25-Oct-09 0:03

Beginner to java

ammu2324-Oct-09 5:05

ammu23

24-Oct-09 5:05

I am beginner to java.so please bring me any small applet programs to do.
Just give me the concept.I will try coding myself...

Re: Beginner to java

Nuri Ismail24-Oct-09 5:51

Nuri Ismail

24-Oct-09 5:51

Here[^] is a good java applet tutorial for beginners. You will find 4 chapters with examples. The code is well commented, but only the basics of applet programming are covered. Anyway, I think that this is a good "learn by examples" tutorial for Java applets.

I hope this helps you. Smile | :)

Nuri Ismail

Re: Beginner to java

ammu2326-Oct-09 19:59

ammu23

26-Oct-09 19:59

Thank you its realy helpful

5 drawings in 5 rectangular regions within one window

WebMaster23-Oct-09 20:19

Re: 5 drawings in 5 rectangular regions within one window

23-Oct-09 20:19

can someone help! I am working with graphics primitives and I am having a problem in creating 5 drawings in 5 rectangular regions within one window.The following is what i have managed to come up with.

import java.applet.*;
import java.awt.*;
import javax.swing.*;

public class Circleline extends JApplet{

int x=300,y=100,r=50;
int xPoints[] = {50,80,80,50,50}; //Sets x coordinates to draw to/from
int yPoints[] = {50,50,80,80,50}; //Sets y coordinates to draw to/from

public void paint(Graphics Obj,Graphics g) //paint function (essential for graphics)
{
Obj.setColor(Color.black); //Sets the color to green
Obj.fillPolygon(xPoints,yPoints,xPoints.length); //Uses the x,y coordinates declared earlier to draw a filled square
for(int i = 0; i < xPoints.length;i++) //for loop to add to x values to move it across screen
xPoints[i] += 200;
Obj.drawPolyline(xPoints,yPoints,xPoints.length); //draws an empty square at the new x values and same y values
}

public void paint(Graphics g){
g.drawLine(3,300,200,10);
g.drawString("Line",100,100);

g.drawOval(x-r,y-r,100,100);
g.setColor(Color.blue);
g.fillOval(x-r,y-r,100,100);

g.setColor(Color.magenta);
g.drawString("Circle",275,100);
g.fillRect(400,50,200,100);
g.setColor(Color.pink);

g.drawRect(400,50,200,100);
g.drawString("Rectangle",450,100);
g.setColor(Color.yellow);

g.drawRect(250,250,250,250);
g.fillRect(250,250,250,250);
g.setColor(Color.gray);
g.drawString("Square",350,350);
}

public void init() //Initialize
{
setBackground(Color.cyan); //Make window background cyan
setSize(400,400); //Set window size

}
}

Please help me so that the code can output 5 drawings in 5 rectangular regions within one window. Thank you

427748024-Oct-09 0:52

Re: 5 drawings in 5 rectangular regions within one window

24-Oct-09 0:52

First you need to specify the regions for example region one is from (0,0), (0,100), (100,0), and (100,100) then when your drawing you should assign the drawings within the range of those region. Do note that you also need to use the frame size coordinates for a better view i.e. all the drawings will be viewed when you launch the application plus when you resize the frame the drawings will also resize.

WebMaster24-Oct-09 1:10

Re: 5 drawings in 5 rectangular regions within one window

24-Oct-09 1:10

Thank you for your answer. If you don't mind can you write for the code of doing what you mentioned above, I will appreciate so much. Thank you

427748024-Oct-09 2:50

Re: 5 drawings in 5 rectangular regions within one window

24-Oct-09 2:50

The basic idea is

        Dimension d = getSize();

int x = (int)d.getWidth();
int y = (int)d.getHeight();

g.drawLine(5, 5, x/10, y/10);
g.drawRect(5, 5, x/10, y/10);

g.fillRect(5+x/10+5+3, 5+3, x/10-6, y/10-10);
g.drawRect(5+x/10+5, 5, x/10, y/10);

g.drawOval(5+x/10+5+x/10+5+1, 5+1, x/10-6, y/10-10);
g.drawRect(5+x/10+5+x/10+5, 5, x/10, y/10);

WebMaster24-Oct-09 8:10

Re: 5 drawings in 5 rectangular regions within one window

24-Oct-09 8:10

Thank you for your support i appreciate so much. This is how I am trying to arrange the code, but it's not running.

import java.applet.*;
import java.awt.*;
import javax.swing.*;

public class  Circleline extends JApplet{
    
    int x=300,y=100,r=50;
     int xPoints[] = {50,80,80,50,50};  //Sets x coordinates to draw to/from
     int yPoints[] = {50,50,80,80,50};  //Sets y coordinates to draw to/from
     
    public void paint(Graphics Obj,Graphics g)  //paint function (essential for graphics)
     {
          Obj.setColor(Color.black);  //Sets the color to green
          Obj.fillPolygon(xPoints,yPoints,xPoints.length);  //Uses the x,y coordinates declared earlier to draw a filled square
          for(int i = 0; i < xPoints.length;i++)  //for loop to add to x values to move it across screen
               xPoints[i] += 200;
          Obj.drawPolyline(xPoints,yPoints,xPoints.length); //draws an empty square at the new x values and same y values
    }
    
    
    public void paint(Graphics g){
          g.drawLine(3,300,200,10);
          g.drawString("Line",100,100);
          
          
          g.drawOval(x-r,y-r,100,100);
          g.setColor(Color.blue);
          g.fillOval(x-r,y-r,100,100);
          
          
          g.setColor(Color.magenta);
          g.drawString("Circle",275,100);
          g.fillRect(400,50,200,100);
          g.setColor(Color.pink);
          
          
          g.drawRect(400,50,200,100);
          g.drawString("Rectangle",450,100);
          g.setColor(Color.yellow);
          
          
          g.drawRect(250,250,250,250);
          g.fillRect(250,250,250,250);
          g.setColor(Color.gray);
          g.drawString("Square",350,350);
          
          d = getSize();
int x = (int)
d.getWidht();
int y=(int)
d.getHeight();
g.drawLine
(5,5,x/10,y/10);
g.drawRect
(5,5,x/10,y/10);
g.fillRect
(5+x/10+5+3,x/10-6,y/10-10);
g.drawRect
(5+x/10+5,5,x/10,y/10);
g.drawOval
(5+x/10+5+x/10+5+1,5+1,x/10-6,y/10-10);
g.drawRect
(5+x/10+5+x/10+5,5,x/10,y/10);
    }
    
     public void init()  //Initialize
     {
          setBackground(Color.cyan);  //Make window background cyan
          setSize(400,400);            //Set window size
          
     }  
}

I will appreciate so much if you help to arrange the code. Thank you

427748024-Oct-09 8:33

Re: 5 drawings in 5 rectangular regions within one window

24-Oct-09 8:33

of course it wont run if you have typo errors use Netbeans or Eclipse. Plus in your paint method I want you to copy the code in my previous post and replace from d.getsize() to the last g.drawrect(). This will run for sure.

WebMaster24-Oct-09 9:47

Re: 5 drawings in 5 rectangular regions within one window

24-Oct-09 9:47

I appreciate so much for your concern. Thank you so much.
I am using JCreator to compile my code. Still it's not running. Do I just copy the code without changing any thing? and where do I copy the code please help me I am new in java programming.

427748025-Oct-09 0:05

Re: 5 drawings in 5 rectangular regions within one window

25-Oct-09 0:05

Dude, my previous post was crystal clear, Use Eclipse or Netbeans not any other IDE.

Paste this code and run:

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

public class Circleline extends JApplet 
{
	public void paint(Graphics g) 
	{
		Dimension d = getSize();
		int x = (int) d.getWidth();
		int y = (int) d.getHeight();
		g.drawLine(5, 5, x / 10, y / 10);
		g.drawRect(5, 5, x / 10, y / 10);
		g.fillRect(5 + x / 10 + 5 + 3, 5 + 3, x / 10 - 6, y / 10 - 10);
		g.drawRect(5 + x / 10 + 5, 5, x / 10, y / 10);
		g.drawOval(5 + x / 10 + 5 + x / 10 + 5 + 1, 5 + 1, x / 10 - 6,y / 10 - 10);
		g.drawRect(5 + x / 10 + 5 + x / 10 + 5, 5, x / 10, y / 10);
	}

	public void init() 
	{
		setSize(400, 400); 
	}
}

WebMaster25-Oct-09 2:28

Re: 5 drawings in 5 rectangular regions within one window

25-Oct-09 2:28

Thank you very much now the code is working. I want to add some colors and text how do I do it? Thank you very much.

427748025-Oct-09 4:29

25-Oct-09 4:29

how about you read the code you supplied it already answers your question.

JPanel Field day issues

shawndeprey23-Oct-09 3:46

shawndeprey

23-Oct-09 3:46

I am currently writing a Dungeons & Dragons Session tool for my final project in my Java class. So far I have the GUI drawn up EXCEPT for one ridiculous problem. For three of my JPanels, named panelNorth, PanelSouth, and guiWrapper, I CANNOT seem to set the background color for them. The first block of code is my driver and the second is the gui class for my program. Can anybody see why it will not set the background color for those 3 specific panels???

p.s. the button listened is commented out because I just want to get the gui working before I continue.

Thanks

import java.awt.*;
import javax.swing.*;
import javax.swing.border.*;

public class ddSessionTool
{
   public static void main (String[] args)
   {
		JFrame frame = new JFrame("Dungeons & Dragons Session Tool");
		frame.setDefaultCloseOperation (JFrame.EXIT_ON_CLOSE);
		
		JPanel panel = new JPanel();
		panel.setLayout (new BorderLayout());
		panel.setBackground(Color.black);
		panel.setBorder (BorderFactory.createEmptyBorder (8, 8, 8, 8));
		
		Gui gui = new Gui();//the graphical user interface of this program...at least the JPanel part.
		
		panel.add(gui);//ADDS THE GUI TO THE PANEL
		
		frame.getContentPane().add(panel);//ADDS THE GUI TO THE FRAME
		
		frame.pack();
		frame.setSize(600,400);
      frame.setLocation(100,100);
		//frame.setResizable(false);
      frame.setVisible(true);
	}
}

//********************************************************************
//  Gui.java       Author: Shawn Deprey    Date: October 12, 2009
//
//  This class creates the GUI for the D&D Session Tool
//********************************************************************

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

public class Gui extends JPanel
{
   public Gui()
   {
		JPanel guiWrapper = new JPanel();//holds ALL the gui
			guiWrapper.setLayout (new BorderLayout());
			guiWrapper.setBackground(Color.red);
		
		JPanel panelNorth = new JPanel();//this is the top "north" panel.
		JPanel panelSouth = new JPanel();//this is the south panel
		
			JPanel topLeft = new JPanel();//houses enemies stuff
				JPanel topLeftNorth = new JPanel();
				JPanel topLeftCenter = new JPanel();
				JPanel topLeftSouth = new JPanel();
				
			JPanel topRight = new JPanel();//houses the players stuff
				JPanel topRightNorth = new JPanel();
				JPanel topRightCenter = new JPanel();
				JPanel topRightSouth = new JPanel();
				
			JPanel rollerSection = new JPanel();//pick rolers name and supply modifier
			JPanel rollDice = new JPanel();//buttons for rolling dice
			JPanel battleOutput = new JPanel();//list bot with battle output
		
		
		//sets up the buttons
		JButton add1 = new JButton("add");//enemies
		JButton add2 = new JButton("add");//players
		JButton remove1 = new JButton("remove");//enemies
		JButton remove2 = new JButton("remove");//players
		JButton d4 = new JButton("D4");//roll 4 sided di
		JButton d6 = new JButton("D6");//roll 6 sided di
		JButton d8 = new JButton("D8");//roll 8 sided di
		JButton d10 = new JButton("D10");//roll 10 sided di
		JButton d12 = new JButton("D12");//roll 12 sided di
		JButton d20 = new JButton("D20");//roll 20 sided di
		JButton d100 = new JButton("D100");//roll 100 sided di
		
		//sets up Labels tl = top left, tr = top right, bl = bottom label
		JLabel placeHolder = new JLabel("THIS TEST IS A PLACE HOLDER FOR SOMETHING ELSE!!!");
		JLabel tlTitle = new JLabel("Enemies");
			tlTitle.setForeground(Color.white);
		JLabel trTitle = new JLabel("Players");
			trTitle.setForeground(Color.white);
		JLabel blTitle = new JLabel("Battle Area");
			blTitle.setForeground(Color.white);
		JLabel blBattleOutput = new JLabel("Battle Output");
			blBattleOutput.setForeground(Color.white);
		
		//sets up the panel layouts.
		panelNorth.setLayout (new BorderLayout());
			panelNorth.setBackground(Color.black);
		panelSouth.setLayout (new BorderLayout());
			panelSouth.setBackground(Color.black);
		//TOP LEFT SECTION
		topLeft.setLayout (new BorderLayout());
			topLeft.setBorder (BorderFactory.createEmptyBorder (0, 0, 4, 4));
			topLeftNorth.setLayout(new FlowLayout());
				topLeftNorth.setBackground(Color.blue);
			topLeftCenter.setLayout(new FlowLayout());
				topLeftCenter.setBackground(Color.gray);
			topLeftSouth.setLayout(new FlowLayout());
				topLeftSouth.setBackground(Color.gray);
		//TOP RIGHT SECTION	
		topRight.setLayout (new BorderLayout());
			topRight.setBorder (BorderFactory.createEmptyBorder (0, 0, 4, 0));
			topRightNorth.setLayout(new FlowLayout());
				topRightNorth.setBackground(Color.blue);
			topRightCenter.setLayout(new FlowLayout());
				topRightCenter.setBackground(Color.gray);
			topRightSouth.setLayout(new FlowLayout());
				topRightSouth.setBackground(Color.gray);
		//BOTTOM SECTION
		rollerSection.setLayout(new FlowLayout());
			rollerSection.setBackground(Color.blue);
		rollDice.setLayout(new BoxLayout(rollDice, BoxLayout.Y_AXIS));
			rollDice.setBackground(Color.gray);
		battleOutput.setLayout(new BoxLayout(battleOutput, BoxLayout.Y_AXIS));
			battleOutput.setBackground(Color.gray);
			
		//adds elements to the top right and left sections
		topLeftNorth.add(tlTitle);
		topLeftCenter.add(placeHolder);
		topLeftSouth.add(add1);
		topLeftSouth.add(remove1);
		
		topRightNorth.add(trTitle);
		topRightCenter.add(placeHolder);
		topRightSouth.add(add2);
		topRightSouth.add(remove2);
		
		//ads elements to the bottom section
		rollerSection.add(blTitle);
		rollDice.add(d4);
		rollDice.add(d6);
		rollDice.add(d8);
		rollDice.add(d10);
		rollDice.add(d12);
		rollDice.add(d20);
		rollDice.add(d100);
		battleOutput.add(blBattleOutput);
		
		//adds components of the top left and top right section to their respective parent panels
		topLeft.add(topLeftNorth, BorderLayout.NORTH);
		topLeft.add(topLeftCenter, BorderLayout.CENTER);
		topLeft.add(topLeftSouth, BorderLayout.SOUTH);
		topRight.add(topRightNorth, BorderLayout.NORTH);
		topRight.add(topRightCenter, BorderLayout.CENTER);
		topRight.add(topRightSouth, BorderLayout.SOUTH);
		
		//adds sub panels to panelNorth and panelSouth
		panelNorth.add(topLeft, BorderLayout.WEST);
		panelNorth.add(topRight, BorderLayout.EAST);
		panelSouth.add(rollerSection, BorderLayout.NORTH);
		panelSouth.add(rollDice, BorderLayout.WEST);
		panelSouth.add(battleOutput, BorderLayout.CENTER);
		
		guiWrapper.add(panelNorth, BorderLayout.NORTH);
		guiWrapper.add(panelSouth, BorderLayout.SOUTH);
		
		add(guiWrapper, BorderLayout.WEST);
		
	}
	//this button listener will wait for a button to be pressed, and will do certain things if they are pressed.
	/*private class ButtonListener implements ActionListener
	{
   	public void actionPerformed (ActionEvent event)
   	{
      	if(event.getSource() == bRed)
      	{
				setBackground (Color.red);
			}
     		else if(event.getSource() == bWhite)
			{
				setBackground (Color.white);
			}
			else if(event.getSource() == bBlue)
			{
				setBackground (Color.blue);
			}
 	 	}
	}*/
}

427748024-Oct-09 0:55

24-Oct-09 0:55

First even if you specify the back color of the parent panel the children panel are already overwriting it for example change the topLeftCenter.setBackground(Color.gray); to any color to see what I mean

shawndeprey24-Oct-09 19:52

shawndeprey

24-Oct-09 19:52

if it is overwriting it for the children then why does the layout work except for those 3 panels? I am not quite certain as to exactly what you are trying to explain to me. Can you please elaborate?

427748025-Oct-09 0:10

25-Oct-09 0:10

ok let me brake it down.

1. In the gui class constructor to change the big gray box add setBackground(Color.yellow);
2. For the three panels you need to add topLeft.setBackground(Color.red); and topRight.setBackground(Color.green);

see it now?

view page source (of a webpage)

shawndeprey25-Oct-09 4:18

shawndeprey

25-Oct-09 4:18

Ok I think I am starting to understand what you are trying to explain to me. Since guiWrapper is the outermost JPanel, I set its background by setBackground(Color.yellow); And borders on my topLeft and topRight JPanels do not actually bleed through to the Panel behind them; since I set no background initially, they were that weird beige color and I needed to define them with topLeft.setBackground(Color.red); and topRight.setBackground(Color.green);.

I added the lines of code and set the color to darkGray, and it worked just fine. I see where my thinking went wrong to. Thank you so much for the help!

sharkbc22-Oct-09 17:56

sharkbc

22-Oct-09 17:56

Hi all !

I want to receive page source from a hyperlink.

This is may code

public class SourceViewer{
  public static void main (String[] args) throws IOException{
	  
	  
    System.out.print("Enter url of local for viewing html source code: ");
    
    
    //BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
   // String url = br.readLine();
    //http://vdict.com/Hello,1,0,0.html
    String url = "http://vdict.com/Hello,1,0,0.html";
    try{
      URL u = new URL(url);
      HttpURLConnection uc = (HttpURLConnection) u.openConnection();
      int code = uc.getResponseCode();
      String response = uc.getResponseMessage();
      System.out.println("HTTP/1.x " + code + " " + response);
      for(int j = 1; ; j++){
        String header = uc.getHeaderField(j);
        String key = uc.getHeaderFieldKey(j);
        if(header == null || key == null)
          break;
        System.out.println(uc.getHeaderFieldKey(j) + ": " + header);
      }
      InputStream in = new BufferedInputStream(uc.getInputStream());
      Reader r = new InputStreamReader(in);
      int c;
      while((c = r.read()) != -1){
        System.out.print((char)c);
      }
    }
    catch(MalformedURLException ex){
      System.err.println(url + " is not a valid URL.");
    }
    catch(IOException ie){
      System.out.println("Input/Output Error: " + ie.getMessage());
    }
  }
}

it work well with some link.

But problem with this link:
http://vdict.com/Hello,1,0,0.html[^]

this is the result form browser and my program:

-Browser:you can see by your self.
-My program:

Date: Fri, 23 Oct 2009 03:53:22 GMT
Server: Apache/2.2.3 (Red Hat)
X-Powered-By: PHP/5.1.6
Expires: Fri, 30 Oct 2009 03:53:22 GMT
Cache-Control: max-age=360000, must-revalidate
Pragma: public
Last-Modified: Fri, 23 Oct 2009 03:53:22 GMT
Vary: Accept-Encoding
Content-Length: 2102
Content-Type: text/html; charset=UTF-8
Set-Cookie: PHPSESSID=4hgviiktc0gc38aiotd8s6jn37; path=/
Connection: Close
 <?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE html PUBLIC "-//WAPFORUM//DTD XHTML Mobile 1.0//EN" "http://www.wapforum.org/DTD/xhtml-mobile10.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
	<meta http-equiv='Content-Type' content='text/html; charset=UTF-8' />
	<meta name='description' content='Vietnamese dictionary and translation for mobile phones and PDAs'>
	<meta name='keywords' content='vietnamese, dictionary, translation, mobile phones, pda, nokia, iphone, blackberry'>
	<meta name='robots' content='index, follow' />
	<meta name='revisit-after' content='1 days' />
	<meta name='resource-type' content='document' />
	<title>Vietnamese Dictionary for Mobile phones and PDAs</title>
	<link href='libs/loadstatic/m.css' rel='stylesheet' type='text/css' />
</head>
<body>
<div class="container">
  <div class="header">VDict mobile</div>
  <div class="menu"><strong>Dictionary</strong> - <a href="t.php">Translation</a></div>  <div class="searchform">
    <form name="frmlookup" id="frmlookup" action="/" method="get" style="margin:0">
      <input name="word" type="text" class="forminput" size="30" value="" />
      <br />
      <select name="dict" class="formselect" >
        <option value="1">English - Vietnamese</option>
        <option value="2">Vietnamese - English</option>
        <option value="3">Vietnamese - Vietnamese</option>
        <option value="5">French - Vietnamese</option>
        <option value="4">Vietnamese - French</option>
        <option value="6">Computing</option>
        <option value="7">English - English</option>
        <option value="8">Chinese - Vietnamese </option>
        <option value="9">Russian - Vietnamese</option>
      </select>
      <br />
      <input name="searchaction" type="submit" value="Lookup" class="subbut" />
    </form>
<div class="result"><br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />    </div>
  </div>
  <div class="footer">&copy; Vdict mobile (<a href="http://vdict.com/?ndr=1">Switch to full version</a>) </div>
</div>
</body>
</html>

Can anybody tell me about this problem and how to fix it.

Thanks and regards !

Re: view page source (of a webpage)

427748024-Oct-09 0:58