Brian Pianczk

Make sure you let everyone know about the cross threads.

http://forums.sun.com/thread.jspa?threadID=5375236&tstart=15

David Ausman wrote:Well, now I feel dumb. In my own defense that download button looks like it is associated with the item above it. I kept clicking on the "docs" button because that is associated with the correct item.

Thanks very much!

I had that same problem.

Campbell Ritchie wrote:If it is a private static field in the Card class, how can you access it from the Deck class?

Oops

public final static int DIAMONDS = 1;

But you haven't actually changed the functionality of the code? It is still taking Player.number and creating a random number in the Player.guess method. It doesn't matter if the instance variable is public and you use a void method, or the instance variable is private and you use a return method. You still get the same result, just your second example protects the instance variable.

I went through this chapter last week, and didn't experience your initial problem.

Thanks to both of you. I understand now, and yes the Card class contains a private static variable for each suit, and rank.

import java.util.*; public class Deck { public static int numSuits = 4; public static int numRanks = 13; public static int numCards = numSuits * numRanks; private Card[][] cards; public Deck() { cards = new Card[numSuits][numRanks]; for (int suit = Card.DIAMONDS; suit <= Card.SPADES; suit++) { for (int rank = Card.ACE; rank <= Card.KING; rank++) { cards[suit-1][rank-1] = new Card(rank, suit); } } } public Card getCard(int suit, int rank) { return cards[suit-1][rank-1]; } }


Having just gone through the section on Arrays, again is this how this bit of code is working?

[numSuits] [numRanks] going down? going across? DIAMONDS ACE TWO THREE FOUR . . . SPADES ACE TWO THREE FOUR . . . HEARTS ACE TWO THREE FOUR . . . CLUBS ACE TWO THREE FOUR . . .

does this loop first make the DIAMONDS column then add the 13 cards to it, then create SPADES then add cards etc...?

amitabh mehra wrote:
the try-catch I suggested was never meant as an "exit" route. It was for that "dirty" exception stack trace which you would not want the user to see.
For exit purpose, perhaps you can prompt the user to enter something like 'quit' and change your code a bit in the way like:
public void getNum(){ Scanner sc = new Scanner(System.in); String num; System.out.print("Enter an integer: "); num = sc.nextLine(); while (!num.equals("quit")) { try { calculate(Integer.parseInt(num)); } catch(NumberFormatException e) { System.out.println("Not a number"); } System.out.println("Enter another integer or type \'quit\' to exit"); num = sc.nextLine(); }; }

Now this will still give "Not a number" message to user in case non-number is entered and allow the user to continue. else 'quit' the application.

Thanks, I am trying to learn java, and all these suggestions help. It is amazing how many solutions there are to one problem, and each one I learn something new.

Jeanne Boyarsky wrote:Brian,
How about using a boolean?

Still thinking about how I can apply this. Are you saying make the whole method a boolean?

amitabh mehra wrote:or use a try-catch block:
do { System.out.print("Enter an integer: "); num = sc.nextLine(); try { calculate(Integer.parseInt(num)); } catch(NumberFormatException e) { System.out.println("Not a number"); } } while (!num.isEmpty());

Thanks for the quick responses!

I like this idea, but I am guessing it would be bad programming to use an exception to exit a program?

Like if I were to say "Enter an integer, or just return to exit: " then use the exception to exit? and display "goodbye" in the exception.


Edit: never mind this idea, doesn't solve the issue if someone enters a non integer.

Hi all, I am trying to figure out a way to exit this do-while. I am wondering how it can be done w/out using a number.
I originally did it with a while num > 0 and used an int num variable, but a neg number can be even or odd.
My new approach gives me an error (unknown source) when it reads a blank entry.


import java.util.Scanner; public class Test { public static void main (String [] args) { Test even = new Test(); even.getNum(); } public void getNum(){ Scanner sc = new Scanner(System.in); String num; do { System.out.print("Enter an integer: "); num = sc.nextLine(); calculate(Integer.parseInt(num)); } while (!num.isEmpty()); } private void calculate(int calcNum) { boolean isEven = (calcNum % 2 == 0); String even; if (isEven){ even = "Yes"; } else { even = "No"; } System.out.println("Is " + calcNum + " even? " + even); } }


Error when I just use a space or enter.
c:\Program Files\Java>java Test
Enter an integer:
Exception in thread "main" java.lang.NumberFormatException: For input string: ""

at java.lang.NumberFormatException.forInputString(Unknown Source)
at java.lang.Integer.parseInt(Unknown Source)
at java.lang.Integer.parseInt(Unknown Source)
at Test.getNum(Test.java:17)
at Test.main(Test.java:7)

c:\Program Files\Java>

Thank you! I looked over this code again and again. Even line by line and did not notice. Even when I pinpointed it to that bit of code.

Thanks again!

OK I have two sets of code here both, to me, look to be the same except for style differences. One I wrote from doing the section in the book MiniMusicPlayer. The other was a direct copy and paste MiniMusicPlayer3.
Mine doesn't work, it plays the track, but doesn't display the random rectangles. The copied and pasted code works.
I can't recognize the difference in the two codes,(myDrawPanel is named different in the two, but referenced the same way) I am curious if anyone else can see something I am not seeing?


Mine
import javax.sound.midi.*; import java.io.*; import javax.swing.*; import java.awt.*; public class MiniMusicPlayer { static JFrame f = new JFrame("My First Music Video"); static MyDrawPanel1 ml; public static void main (String [] args) { MiniMusicPlayer mini = new MiniMusicPlayer(); mini.go(); } public void setUpGui() { ml = new MyDrawPanel1(); f.setContentPane(ml); f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); f.setBounds(30, 30, 300, 300); f.setVisible(true); } public void go() { setUpGui(); try { Sequencer sequencer = MidiSystem.getSequencer(); sequencer.open(); sequencer.addControllerEventListener(ml, new int[] {127}); Sequence seq = new Sequence(Sequence.PPQ, 4); Track track = seq.createTrack(); int r = 0; for (int i = 0; i < 60; i += 4) { r = (int) ((Math.random() * 50) +1); track.add(makeEvent(144, 1, r, 100, i)); track.add(makeEvent(176, 1, 127, 0, i)); track.add(makeEvent(128, 1, r, 100, i + 2)); } sequencer.setSequence(seq); sequencer.start(); sequencer.setTempoInBPM(220); } catch (Exception ex) {ex.printStackTrace();} } public MidiEvent makeEvent (int comd, int chan, int one, int two, int tick) { MidiEvent event = null; try { ShortMessage a = new ShortMessage(); a.setMessage(comd, chan, one, two); event = new MidiEvent(a, tick); }catch (Exception e) {} return event; } class MyDrawPanel1 extends JPanel implements ControllerEventListener { boolean msg = false; public void controlChange(ShortMessage event) { msg = true; repaint(); } public void paintCompenent (Graphics g) { if (msg) { Graphics2D g2 = (Graphics2D) g; int r = (int) (Math.random() * 250); int gr = (int) (Math.random() * 250); int b = (int) (Math.random() * 250); g.setColor(new Color(r, gr, b)); int ht = (int) ((Math.random() * 120) + 10); int width = (int) ((Math.random() * 120) + 10); int x = (int) ((Math.random() * 40) + 10); int y = (int) ((Math.random() * 40) + 10); g.fillRect(x, y, ht, width); msg = false; } } } }

Copied version

import javax.sound.midi.*; import java.io.*; import javax.swing.*; import java.awt.*; public class MiniMusicPlayer3 { static JFrame f = new JFrame ( "My First Music Video" ); static MyDrawPanel ml; public static void main ( String[] args ) { MiniMusicPlayer3 mini = new MiniMusicPlayer3 ( ); mini.go ( ); } public void setUpGui ( ) { ml = new MyDrawPanel ( ); f.setContentPane ( ml ); f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); f.setBounds ( 30, 30, 300, 300 ); f.setVisible ( true ); } public void go ( ) { setUpGui ( ); try { Sequencer sequencer = MidiSystem.getSequencer ( ); sequencer.open ( ); sequencer.addControllerEventListener ( ml, new int[] { 127 } ); Sequence seq = new Sequence ( Sequence.PPQ, 4 ); Track track = seq.createTrack ( ); int r = 0; for ( int i = 0; i < 60; i += 4 ) { r = ( int ) ( ( Math.random ( ) * 50 ) + 1 ); track.add ( makeEvent ( 144, 1, r, 100, i ) ); track.add ( makeEvent ( 176, 1, 127, 0, i ) ); track.add ( makeEvent ( 128, 1, r, 100, i + 2 ) ); } sequencer.setSequence ( seq ); sequencer.start ( ); } catch ( Exception ex ) { ex.printStackTrace ( ); } } public MidiEvent makeEvent ( int comd, int chan, int one, int two, int tick ) { MidiEvent event = null; try { ShortMessage a = new ShortMessage ( ); a.setMessage ( comd, chan, one, two ); event = new MidiEvent ( a, tick ); } catch ( Exception e ) { } return event; } class MyDrawPanel extends JPanel implements ControllerEventListener { boolean msg = false; public void controlChange ( ShortMessage event ) { msg = true; repaint ( ); } public void paintComponent ( Graphics g ) { if ( msg ) { Graphics2D g2 = ( Graphics2D ) g; int r = ( int ) ( Math.random ( ) * 255 ); int gr = ( int ) ( Math.random ( ) * 255 ); int b = ( int ) ( Math.random ( ) * 255 ); g.setColor ( new Color ( r, gr, b ) ); int ht = ( int ) ( ( Math.random ( ) * 120 ) + 10 ); int width = ( int ) ( ( Math.random ( ) * 120 ) + 10 ); int x = ( int ) ( ( Math.random ( ) * 40 ) + 10 ); int y = ( int ) ( ( Math.random ( ) * 40 ) + 10 ); g.fillRect ( x, y, ht, width ); msg = false; } } } }

Hi all, is there any way to return a method's origin?

Besides typing in toCharArray in a Google search box; is there a way to display where a method is located, using Java?

Like a getClass() ?

Edit: Just using toCharArray as an example, I don't want to know that method specifically. I know it is in java.lang.String.

I appreciate the patience, thanks to both of you. I now understand what exactly is going on.

Maneesh Godbole wrote:Whenever you stretch, resize, move the window, the JVM repaints it. And guess where your to paint the circle sits? In the paint method!

Though the paint is the correct place to have the circle code, if you want a consistent color, irrespective of what you do, just move your color generation code outside paint. Every time the paint is called, your code comes up with a new color.

Ok if I understand corectly , my problem is in :
class MyDrawPanel extends JPanel{ public void paintComponent(Graphics g) { Graphics2D g2d = (Graphics2D) g; int red = (int) (Math.random() * 256); int green = (int) (Math.random() * 256); int blue = (int) (Math.random() * 256); Color startColor = new Color(red, green, blue); red = (int) (Math.random() * 256); green = (int) (Math.random() * 256); blue = (int) (Math.random() * 256); Color endColor = new Color(red, green, blue); GradientPaint gradient = new GradientPaint(70,70, startColor, 150,150, endColor); g2d.setPaint(gradient); g2d.fillOval(70, 70, 100, 100); } }

Before I go into the errors I have found trying to minipulate that class, could we confirm this is the source of my "trouble"?

Thanks

I am assuming by when you say paint, you are referring to lines 16 and 17?