How Wait And Notify Works In Multithread Environment
Aug 26, 2014Flow of this program?
public class ThreadA {
public static void main(String [] args) {
ThreadB b = new ThreadB();
b.start();
synchronized(b) {
[Code] ...
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JavaFX 2.0 :: ChangeListener Don't Notify Selected Item Property Changes
May 13, 2014I made a simple test case using a ListView<String>.:
@FXML
ListView<String> listView2;
@Override
public void initialize(URL arg0, ResourceBundle arg1) {
listView2.getItems().clear();
[Code] ....
Using Java8 I see that I see this wrong behavior:
select 3 elements from the list: you'll see the log of the ChangeListener that tell you every time all items selected
remove 1 element from previous selection: you will not receive the notification!!!
remove the other two elements: only when the selection is empty you will see a new notification from changeListener...
Tell Java Method To Wait One Second?
Jul 4, 2014I want to tell my java method to wait one second while something else is happening. Why not use Thread.sleep(x)? For me it stops the whole program and does not let that some else happen. Why not use wait(x)? It crashes. I tried using timers, but that doesn't solve the problem... Isn't there a simple "Java please wait 1 sec for him to catch up"?
View Replies View RelatedMethod To Wait On Different Swing Window?
Dec 20, 2014I am trying to create a gambling POS system and having problems with a method trying to get a value right after it was set. A jbutton sets another jframe visible which contains buttons. Upon action of the button, a value is set and the jframe is disposed.
private void btnPrizeActionPerformed(java.awt.event.ActionEvent evt) {
PrizeSelling prize = new PrizeSelling();
prize.setVisible(true);//create prize selection window
bin = getButton(); //gets what button is selected to load the correct prizes for correct game
prize.DBconnect(bin);//sends bin number to prize loading method
[Code] ....
As soon as btnPrize is clicked it gets the total value of the prizes selected which of course is 0 because it is ran before it is set. How can I make it wait until the window is closed before continuing?
Command To Wait For User Input
Apr 28, 2014I am new to Java but not to programming, and I wonder what command there is available in Java to put a pause in the program sequence, for instance when you display "press any key to continue... "?
View Replies View RelatedTwo Different Buttons - Wait And Resume Function
May 5, 2014i have two different buttons. when i clicked first, the picture is shown and then when clicked second button it shown picture and both of will be closed. but i cant see second picture because immediately second button will be closed. how can i stopped second button for a 3 seconds fpr example?
View Replies View RelatedWait For External Application To Close
Jun 16, 2014I am writing a console application that is to make use of the system editor on *NIX. For that I have written a method which writes a string to a file, launches an editor to change that file, and then reads the file again. The problem is the call to run the editor doesn't wait for that application to have closed.
Java Code: Runtime.getRuntime().exec(editorcmd + " " + tmpfn); mh_sh_highlight_all('java'); I need the program to wait for the editor to have finished.
Swing/AWT/SWT :: What Makes Java Wait On JFrame
Mar 8, 2014With a simple "Hello World" application, once the println is executed the application exits and the process goes away.
If a simple Frame application is executed, the Frame is displayed, the println is executed but the application does not exit.
public class Frame3 extends JFrame
{
Frame3() {
setBounds(100,100,300,100);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setVisible(true);
}
public static void main(String args[]) {
new Frame3();
System.out.println("You are here");
}
}
It isn't that Java is aware an object exists because if I create a basic non-swing, non-gui object it will exit right after the println.
Q1. What is it that causes Java NOT to exit after creating the JFrame?
Q2. What type of object(s) when created will cause the application to continue running?
Q3. What would I do if I wanted the println statement to be executed only after the JFrame was closed?
Swing/AWT/SWT :: Wait For Mouse Click Before Running While Loop
Oct 7, 2013I've got the game working just fine, but I don't like the way it starts playing the second you hit the "Run Last Class" button in Eclipse, and would really like to have the game start, then wait for the user to click a button before running the core WHILE loop. Everything is implemented in a single class, and here is the playGame method that starts the ball moving:
private void playGame(){
while (!gameover){
moveBall();
checkForCollisions();
}
All I want to do is pause before the WHILE loop until the users clicks the mouse button, nothing fancier than that! I've done quite a bit of reading, and it looks like ActionEvent may be the way to go, but I'm not clear on how to use it correctly in this scenario.
How To Set Environment Variables
Apr 13, 2014I am new in this programming language, java. I have a problem after I set my path ";C:Program Files (x86)Javajdk1.7.0_51in". I made a simple program but an error occurred. Here's the screenshot.....
Attached image(s)
Swing/AWT/SWT :: Have Object Notify Main Object
Jan 15, 2015What I want to do is have a label that is updated whenever an object gets some new, relevant data.The way you do it in Java looks different from the way we do it in Objective-C. In Objective-C, we have what's known as a protocol. An Objective-C protocol is almost exactly like a Java "implementation." In Obj-C, if I want the user to see the address of where he is, I can have an object that gets the information and invokes a view controller's method; at that point, the view controller would then take the data passed to it and display the data in a label. However, the view controller is an instance of a subclass of the bundled view controller class.
View Replies View RelatedEJB / EE :: Use Asynchronous Annotation In Distribute Environment
Jul 18, 2014Can we use EJB @Asynchronous annotation in distribute environment. I know we can use it but I want to know its Advisable or not. Because It's not advisable to manage user thread in Distribute environment like EJB container .Earlier if we want to make Asyn call then we use JMS. But now they added @Asynchronous annotation with Future Class to achieve the same result.
View Replies View RelatedEnvironment Independent Single WAR Generation
Oct 8, 2014I have a project which has a set of configuration files, where each configuration file represents an environment specific configurations. In other words, I have 3 environments, development, staging, and production. The configuration for each environment is different, e.g. DB name, url etc.
Whenever I want to deploy the same code, on each environment, I have to manually generate environment specific .war file, so that it has environment specific configuration file in it.
What I am looking for is a kind of solution where i have to compile only once in maven and it generates only one .war file, which I can use on every environment. In other words, i want the environment specifi application server/tomcat to identify which configuration to pick.
That way, I'll be sure that we are deploying and testing the same .war file on every environment/application server.
How can i restructure the application to achieve this functionality?
Unable To Run Tshark Command Using Runtime Environment On Ubuntu
Sep 19, 2014I am trying to run tshark command using runtime environment in java on ubuntu . My code is as follows :-
try {
String destip = map1.get((String) innObj.get("value"));
Runtime run = Runtime.getRuntime();
String tshk = "/usr/bin/tshark -r /home/pratibha/Desktop/vox.pcap -Y "ip.dst == "
+ destip
+ " && http" -T fields -e tcp.port -e col.Info";
Process pr = run.exec(tshk);
[Code]...
map1 is hashmap which contains the destination ip adress When i run the above code the exit code for process (pr) is 1 and hence the tshark command is not executing properly.
Fatal Error Has Been Detected By Java Runtime Environment
Jul 8, 2014While executing my application i came across with this unexpected error which i don't know why?
#
# A fatal error has been detected by the Java Runtime Environment:
#
# EXCEPTION_ACCESS_VIOLATION (0xc0000005) at pc=0x000007fdcacd79a9, pid=4980, tid=7724
#
# JRE version: Java(TM) SE Runtime Environment (7.0_45-b18) (build 1.7.0_45-b18)
# Java VM: Java HotSpot(TM) 64-Bit Server VM (24.45-b08 mixed mode windows-amd64 compressed oops)
# Problematic frame:
# C [ntdll.dll+0x79a9]
#
# Failed to write core dump. Minidumps are not enabled by default on client versions of Windows
#
# If you would like to submit a bug report, please visit: [URL} .....
# The crash happened outside the Java Virtual Machine in native code.
# See problematic frame for where to report the bug.
#
Input Ten Words And Output Them Backwards In MSDOS Environment
Sep 4, 2014how would a program code look like, input ten words and output them backwards in a msdos environment. My code this far is:
package baktext;
import java.util.*;
import java.io.*;
import java.awt.*;
//public static String baklänges(String s) {
//}
public class Baktext {
[Code] ....
Registry Refers To Nonexistent Java Runtime Environment Installation
Mar 13, 2015I was having trouble running some Java programs (not my own) in Windows XP, and in the process I uninstalled and installed JRE versions 6, 7, and 8, one at a time, probably in the order 7, 8, 7, 6, 7. The program that had the original problem only worked in V6, but some other programs stopped working. I went back to V7, and those other programs still didn't work. The message was "the registry refers to a nonexistent java runtime environment installation". The only advice I could find with Web searches was to reinstall the JRE. Needless to say, that didn't work.
So I looked at the registry, and I found that there were still references to V8, which had been uninstalled. The first was
HKEY_CLASSES_ROOTjarfileshellopencommand - (Default) = "C:Program FilesJavajre1.8.0_31binjavaw.exe" -jar "%1" %*
The folder re1.8.0_31 doesn't exist, so I changed it to jre7. That didn't work.
Then I found
HKEY_LOCAL_MACHINESOFTWAREJavaSoftJava Runtime Environment - CurrentVersion = 1.8
I changed this to 1.7, and deleted some following entries such as
HKEY_LOCAL_MACHINESOFTWAREJavaSoftJava Runtime Environment1.8 - JavaHome = C:Program FilesJavajre1.8.0_31
retaining entries such as
HKEY_LOCAL_MACHINESOFTWAREJavaSoftJava Runtime Environment1.7 - JavaHome = C:Program FilesJavajre7
That worked!
So, there is a bug in the installer(s): if you uninstall V8 and install V7, the 'CurrentVersion' isn't set correctly, with the result that the registry points to a non-existent folder. The V8 uninstallation should delete these entries, or the V7 installation should change them.
Error - Could Not Find Required Version Of Java(TM) 2 Runtime Environment In (null)
Jun 30, 2014I have installed and tested j2se jdk8 u5 on my Windows 7 64 bit laptop and successfully tested in Eclipse with a quick Hello World.
JAVA_HOME = C:Program FilesJavajdk1.6.0_25
When I try to install j2ee jdk7 sdk7 I get
Error: Could not find the required version of the Java(TM) 2 Runtime Environment in '(null)'
JavaFX 2.0 :: How To Create Off Screen Images By Canvas In Multi-thread Environment
Feb 25, 2015I want to create off-screen images by Canvases in multi-thread environment.
I know that I use methods of GraphicsContext2D to draw on Canvas. Can I do this on Canvas which is not added to Scene ?
How can I get an image from a canvas after I invoke GraphicsContext2D methods? Can I get images in multi-thread environment ?
Could Program Fail With Race Condition By Concurrent Threads In A Multi Thread Environment
Feb 18, 2014I have a task of returning US holiday based on the given date and this utility will be used in a multi thread environment. I have written as below, how to know if my code breaks at any given point by multiple threads
Declared Enum
public enum Holiday {
CHRISTMASDAY("Christmas Day"),
GOODFRIDAY("Good Friday"),
INDEPENDENCEDAY("Independence Day"),
LABORDAY("Labor Day"),
NONE("None");
[code]...
I tried to test this with few concurrent threads, and noticed that the DB call is made for the very first time or when the year being requested is not same as the cached year. But I wanted to see, if this is properly synchronizing and would not fail in any case. My intention is to make a singleton HolidayCalendar, and also synchronized well enough so that every thread using this class gets the required data without blocking each other.
How DrawImage Works
Jun 14, 2014I copied this right out of oracle almost. And yet it won't draw.
ImageIcon salt = createImageIcon("icons/bathsalts.jpg");
/**
* @Override
*/
public void draw(Graphics g){
Graphics2D g2d = (Graphics2D) g;
g2d.drawImage(salt, getX(), getY(), null);
}
why draw image doesnt work for me. drawRect and circle are going just fine...
protected static ImageIcon createImageIcon(String path) {
try{
java.net.URL imgURL = ButtonPanel.class.getResource(path);
return new ImageIcon(imgURL);
} catch(RuntimeException e) {
System.out.println("Invalid file path");
}
return null;
}
App Works Locally But Not From Website
Feb 9, 2014I have a Java application that was built by a third party and my task is to embed this in a web site. To do so I got an HTML snippet, a .JAR and da .DAT file that seems to be called by the app. I tested this locally on my machine and it works ok. After uploading to the web server I get an error message
NumberFormatException For input string: "i>>?<html>"(the question mark is actually upside down, the >> is really one character)
At first sight this looks like a common issue with UTF-8 file being delivered when the file itself holds only ANSI characters (or vice versa). So I made sure that the .HTM and the .DAT file are indeed stored in ANSI 8-bit (and not Unicode 16-bit) format. However, this does not solve the issue. The .HTM file itself also holds a ISO 8859-1 directive. The server is set to deliver UTF-8 by default. I cannot change this due to a huge lot of other dependencies.
So I am not sure if my suspicion is right - is it indeed a character set issue? Or is it something else?
The test file is on [URL] ....
Creating Array That Works Like A Torus
Mar 14, 2014I have create a program that takes a random array which is created by starting from 0 and adding Math.random() (double between 0 and 0.999) n times, and calculates the weighted average of each position within a certain radius. I currently have a program that does this but i was wondering how to create one using a torus. The basic principle is the last element is now equal to the first element and when the first element updates its position it takes into account the difference between the other elements including some of the last elements in the array.
Heres the code so far that works for one iteration. After one the code is incorrect and calculates the wrong values. I think using a circular list or a ring buffer may work but i have little experience with either.
import java.text.DecimalFormat;
import java.util.Scanner;
public class Torus {
public static void main(String[] args) {
DecimalFormat df = new DecimalFormat("#.###");
[Code] ....
Variable Is Set Works / But Then In Void - Returns 0
Jun 13, 2014The id variable is the problem Java Code: package com.cjburkey.games.boxee.objects;
import java.awt.Graphics;
import java.awt.Rectangle;
import com.cjburkey.games.boxee.GameState;
import com.cjburkey.games.boxee.resources.Images;
public class Block extends Rectangle {
[code]...
In the constructor, it returns corrent numbers, in the draw method, it returns 0. Why?
Netbeans Jmenu Popup Only Sometimes Works
Nov 30, 2014I am having issue with jmenu popup in netbeans. It only sometimes works. Sometimes I don't get a java popup at all. Sometimes my File and Edit options are completely missing. This is what my code looks like.
import javax.swing.*;
public class menu {
/**
* @param args the command line arguments
*/
public static void main(String[] args) {
// TODO code application logic here
JFrame f = new JFrame();
f.setVisible(true);
[Code] .....
EJB / EE :: SSL Works Only If Client And Server Are At Same Host
Jun 9, 2014I have gf 4.0.1 and swing client. I want to get EJB over SSL. I've set all certificates. However, I can get it work only when client and server are at the same host. What I see in tcpdump when they are at the same host:
10.0.17.2.48524 > 10.0.17.2.3820: Flags [P.], cksum 0x378f (incorrect -> 0xf2b6), seq 399:756, ack 1085, win 273, options [nop,nop,TS val 347297976 ecr 347297966], length 357
13:01:26.334898 IP (tos 0x0, ttl 64, id 51559, offset 0, flags [DF], proto TCP (6), length 665)
10.0.17.2.3820 > 10.0.17.2.48524: Flags [P.], cksum 0x388f (incorrect -> 0x626d), seq 1085:1698, ack 756, win 273, options [nop,nop,TS val 347297977 ecr 347297976], length 613
[code]...