Inside a While Loop (While Loop begins if a condition is True) I have an If Statement, the else part of the statement assigns False to the condition I mentioned earlier.
But I've tried de-bugging and even when the code goes through the else part of the statement, firstly it returns False but then it returns to the beginning of the loop as True again.
I have a swing application that gets football scores from a website using Jsoup.
When the "Get Scores" button is pressed, the scores are printed to a JTextArea with a JScrollPane.
I have also used a SwingWorker to update the scores every couple of seconds.
My problem is that every time the JTextArea updates, the JScrollPane scrolls back to the top of the text area. I wan the scroll bar to stay where the user left it.
Here is my code (The update is currently set to update every 1 second so you can see what the scroll bar is like).
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import org.jsoup.Jsoup;
import org.jsoup.nodes.Document;
import org.jsoup.select.Elements;
public class frame extends JFrame {
[Code] ....
I am trying to remove a line based on user input. myFile.txt looks like:
Matt
Brian
John
However when I enter "Brian" (to remove this line), It is deleted on the temp file (myTempFile.txt), but not renamed back to the original file (myFile).
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.util.Scanner;
[code]....
In the code that I am currently trying to do, I want to make it so that the program loops until the randomly generated number is 1, to a maximum of 4 loops.I have figured out how to make it stop at a randomly generated 1, but I can't quite figure out how to make it stop at four loops if it doesn't reach the 1 before the maximum number of loops.
View Replies View RelatedI am developing application called java compiler... It takes java program as input and compiles and run it, gives output. but if input program has infinite loop then how can identify and stop process execution.
View Replies View RelatedI am making a project that should play, stop, and loop three different songs (not at the same time). I am calling this SoundPlayer class from my main class:
import javax.sound.sampled.*;
import java.util.*;
public class SoundPlayer {
List<AudioInputStream> songs = new ArrayList<AudioInputStream>();
int currentSong, currentPlayType;
[Code] ....
When my class calls setPlayType(2), which should make it play, I get the following runtime error:
java.lang.NullPointerException
at SoundPlayer.playSong(SoundPlayer.java:32)
at SoundPlayer.setPlayType(SoundPlayer.java:64)
at MainPanel$AListener.actionPerformed(MainPanel.java:60)
(...)
Line 32 is if(clip.isOpen()), but I'm pretty sure I instantiated clip properly in the constructor.
I'm having trouble understanding how this loop is broken, I can't understand how the boolean finished is set to false and breaks the While loop.
public void run()
{
char answer;
boolean finished = false;
while(!finished)// when false loop is broken
[Code] ....
In attempting to find the greatest common divisor (gcd) of two integers, n1 and n2, whereas k is a possible gcd and gcd is initialized to 1, the following code has been entered:
for (int k = 2; k <= n1 && k <= n2; k++) {
if ( n1 % 2 == 0 && n2 % 2 == 0)
gcd= k;
}
When asked to change the previous line of code to this:
for (int k = 2; k <= n1 / 2 && k < n2 / 2; k++){
the questions states this revision is wrong and to find the reason.....well, I've changed it, entered "3" (per the answer key) for n1 and n2....
now I can see logically where k (2 in this example) is not <= n1/2, which is 3/2 or 1, since we're dealing w/integers, yet when I compile and run, my answer is indeed, gcd = 1. However, since this is a Boolean expression where && is being used, since the first portion evaluates to "false", the 2nd portion isn't executed and thus my result of 1?...... loops are throwing me for one, for sure....
Why when I do this:
System.out.println((byte) 99);
I still get: 99 ... not the hex representation of the byte!!
Why is that?
So In my program I have a String called original and I am supposed to prompt the user for a sentence and then Make a StringBuilder instance called “originalReversed” based off of original. Then I have to do is to "Manipulate originalReversed so that it contains the value of original in reverse. This is done with a single statement."
import java.util.Scanner;
public class StringBuilderPractice {
public static void main(String [] args)
{
Scanner input = new Scanner(System.in);
String original;
System.out.println("Please enter a sentence: ");
original = input.nextLine();
}
how to create the instance but not the second part where it says manipulate the value for the first part I think it might be
StringBuilder originalReversed = new StringBuilder(original);
I'm doing a software Java GUI - JFrame form like this:
1. The user wants to click on a button that opens a bunch of images that will be displayed as thumbnail in the bottom of the JFrame .
2. Then the user wants to select/click one of the thumbnail and make appear the corresponding image in it's original size on above(center) of the JFrame.
For doing this I used 3 JPanel.
One contains a JButton that opens the jfilechoser dialog window,
the second "panelPreview" is for putting the thumbnails created,
and the third "panelGrande" is for the image in it's original size.
The firs part "1." is ok.
But in the second part : I got one error when I want to put the ImageIcon in to the JLabel with the further intent of displaying it.
lblBig(imgIcoVett[i]);
In this project I'm dealing with arrays of ImageIcons and JLabels, so it's a bit advanced level for me, so I'm not sure that I wrote right the part of the MouseListener too.
The error displayed by netbeans says "cannot find symbol symbol: method lbl (ImageIcon) local variables referenced from an inner class must be final or effectively final"
Here I attach the project I did with netbeans"AAAD Unlayout 2.zip", but if you just need the highlight of the code, here it is too:
private javax.swing.JButton btnOpenfile;
private javax.swing.JFileChooser jFileChooser1;
private javax.swing.JPanel jPanel1;
private javax.swing.JLabel lblBig;
private javax.swing.JPanel panelGrande;
private javax.swing.JPanel panelPreview;
[Code] ....
I am working on a program that simulates a bug moving along a horizontal line, My code works correctly when I test it in it's own class but when I tried testing my constructor and methods in a test class I received an error saying, "package stinkBug does not exist" on lines with my methods. However, stinkbug is not a package.
Java Code:
/*
* To change this license header, choose License Headers in Project Properties.
* To change this template file, choose Tools | Templates
* and open the template in the editor.
*/
[code]....
The problem is the result of encoded message can't not restore to the original message by the decoder. Here are my three class's code
SecureMsgMain:
package securemsg.core;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Scanner;
import securemsg.database.*;
public class SecureMsgMain {
[Code] .....
how many integers the user wants to use. The user will enter for example a 4. The user inputs a 2, 4, 6, and 10. So then we get our outputs...Then the code will ask if you want to run this program again. My question is, if the user inputs a -1 for example 2, 4, 6, -1....the code will not continue. I wanted to use a while loop, such as while (scores != -1) but it doesn't work.
Enter the amount of integers you want to use4
Intenger # 1 2
Intenger # 2 4
Intenger # 3 6
Intenger # 4 10
You entered 2.0 4.0 6.0 10.0
Average = 5.5
Variance = 8.75
Standard Deviation = 2.96
Do you have another set of numbers?
[code]....
I made a check4 application with Java.It correctly works but sometimes the application just stop itself during the execution.I never had a problem like this. The application just stop itself and i can't even quit using the closing button..
View Replies View RelatedWhat I mean is, I have this set and it is supposed to take out all the duplicates. If I enter aaabbbcccd the output should be abcd, but instead my code just outputs the last word, or in this case letter entered.
import java.util.*;
public class setdemo
{
public static void main(String[] args)
[Code]....
I am making a WebCrawler, and I am trying to work out a way to stop duplicate links from getting put in however ArrayList.contains() doesnt seem to be working for me can someone look at my code and see if I am doing something wrong? I have also tried variations of it such as
!link.contains(newLink)
and
!link.contains(newLink.getLinkUrl())
with no luck. The Problem area is
for(Element lnks: link){
linkSrc = lnks.absUrl("href");
WebPage newLink = new WebPage(linkSrc);
if(!link.contains(linkSrc)){
links.add(newLink);
[Code] .....
I am trying to program a slot machine and as of now, I am trying to make my slots spin and randomly stop on one of the graphics. Right now, I am having difficultly making the animation/slot stop randomly.
Previously, I tried using a randomly set timer that would cancel the execution, but the image did not appear/stop on the screen.Right now, I am using a random generator and a while to say that if it is a certain number, then stop the image.Here's what I tried:
import java.applet.*;
import java.awt.*;
import hsa.*;
import java.util.Random;
public class SlotGraphics
{
Console c;
int x = 200;
int y = -100;
[code]....
I have a Stream instace which produces values using an infinite Supplier (it supplies values taken from an electronic sensor -- so unless the battery is low, the sensor will provide "for ever").
The stream is processed by a Collector using Stream.collect() (e. g. imagine that the values from the sensor should be averaged; in fact what it does is a bit more compliacted maths).
The problem is that the collector does not produce a result but hangs up, as the supplier does never stop providing more sensor values.
So what I need is a limitation rule that stops the stream. While there is a Stream.limit(long) method, it actually does not solve my problem as in my case it is not practical to stop after a particular count, while I actually want to stop streaming when the sensor value exceeds a particular limit etc. (hence, voids an arbitrary rule).
To sum up, what I need is Stream.limit(Predicate), i. e. the stream will stopped once the predicate becomes true.
Unfortunately I did not find anything like that in JRE 8.
Is that planned for JRE 8.1 or JRE 9.0? Or is there a known (and sophisticated) workaround?
Is there any way to compile a program without calling constructor.
View Replies View RelatedI am trying to make a stopwatch using the timer class and JButtons. When I run my program and I hit start the time stays at zero. What I want my stopwatch to do is when I press start it shows the number of seconds that have passed. The start button will then become disabled and the stop button will be the only button able to be pressed. When you hit stop it should enable only the start and restart buttons. Here is my code.
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.*;
public class StopWatchPanel extends JPanel
{private final int DELAY = 1000;
[code]....
Let's say we have a matrics of coordinates:
(0,0) (0,10) (0,20)
(10,0) (10,10) (10,20)
(20,0) (20,10) (20,20)
And we have a class that draws a rectangle of 10 pixel height and 10 pixel width at 0,0 coordinates.
And we want to move with the arrows the rectangle but not to go off the frame.
The question is:
How can I do that if I draw another rectangle, it knows where is the other object and they not collapse. And so on, they move, but not collapse, just touch and stop.
I have a servlet which sends HTML5 server sent events to the jsp client. The servlet sends data to the client every one second. The jsp client instantiates a new eventsource and recieves the data. When the window is about to close, the jsp client closes eventsource at the "beforeunload" event (shown in the code below).
However, I have noticed that even after the client closes the eventsource and the browser exits, the server continues sending data. As far as the documentation on eventsource goes, using eventsource.close() is enough to stop client from reconnecting to the server and the server will stop sending any further push notifications.
Why the server does not stop sending push notifications even after eventsource.close() and the browser exit? Do I write any other piece of code to notify the server to stop sending data once client exits?
Pasted below are the servlet (server ) code and the client code.
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
[Code] .....
I've got my clear button to work on most of the stuff I want, however I cant figure out how to fix the price to stop adding up. e.g. hit a button image with a price of 599.99, hit the clear button to empty, select price of 599.99 again then it display 1199.98.
sofa method
if (source == jBSofa) {
System.out.println("Sofa"); {
dTotal = dTotal + 599.99;
jTotal.setText(Double.toString(dTotal));
jTotal.setText(String.format("%.2f", dTotal));
}
Reset method
private void Reset() {
jTTotal.setText(" ");
jTotal.setText(" "); //sub total clear
jTTotalTotal.setText(" ");
Attached image(s)
i am writing a program that would be used for ticket sales and their are 100 tickets and a person can only buy 4 at a time. i need my program to not go negative at the end and also i need to stop the user from entering a negative number.
import java.util.Scanner;
public class ticketmaster {
public static void main(String[] args) {
// Variable decoration uses strings , doubles and final doubles.
Scanner in = new Scanner(System.in);
[code]....
i am writing a program that would be used for ticket sales and their are 100 tickets and a person can only buy 4 at a time. i need my program to not go negative at the end and also i need to stop the user from entering a negative number here is the code.
import java.util.Scanner;
public class ticketmaster {
public static void main(String[] args) {
// Variable decorationuses strings , doubles and final doubles.
Scanner in = new Scanner(System.in);
[code]....