I made UpdateInmateDisplayer a Singleton so that I could access it from the private class ButtonHandler. It works to display the first inmate's number on the screen but when I close out the window and click the Book Inmate button in CurInmatesDisplayer again, it only shows a blank window. I've tried adding the components again from the ButtonHandler in CurInmatesDisplayer but it doesn't work.
View RepliesI have a simple method in Java through which I send commands to a machine over TCP. The problem is:
Machine can't accept more than two connections in 20 seconds.
I need to send 15-20 commands to the machine in 3 minutes.
This is my current method which is not working as it should, 2 commands get transmited but third command hangs because of the machine.
void sendCommand(String command) throws IOException {
String ipaddress = "192.168.0.2";
Socket commandSocket = null;
BufferedWriter out = null;
BufferedReader in = null;
BufferedWriter outToDetailFile = null;
[Code] .....
Basically what i need is:
1st: I need to open the connection by calling method
public void openConnection(String ipaddress, String port){
//Code to start the connection
}
2nd: I need to be able to send commands to the connection I have already opened (i will send multiple messages in time period of 5-10 minutes):
public void sendCommand(String message){
}
3rd: Close that connection
public void closeConnection(){
}
Following is the code on the click of a button, id like to know how do i close the current jframe on which the jButton4 is currently placed. I know how to send it to the next Jframe i.e JobCard. But need to close the current one. I tried using this.setVisible(true); But it does not work.
private void jButton4ActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
this.setVisible(false);
JobCard jobCard = new JobCard();
jobCard.setVisible(true);
}
I didn't know about right method for correct close operation for JFrame component or kill the object. I found out few, which of them you are using usually???
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setVisible(false);
JFrame.DO_NOTHING_ON_CLOSE.
System.exit(0);
How to make a Jframe close without closing the whole operation, I started off using exit on close and changed it to hide on close and i also tried dispose on close for some reason it wont work. Here is what I have.
import java.awt.*;
import javax.swing.*;
public class GUILauncheralt{
public static void main(String[] args){
RetrieveWindow gui = new RetrieveWindow();
gui.setDefaultCloseOperation(JFrame.HIDE_ON_CLOSE);
gui.setSize(400, 200);
[Code] .....
I have JFrame and when I click a button which is in frame JDialog is opened. Now,how can I refresh JFrame when close JDoalog?
View Replies View RelatedI am making a simple battleship program, you have the menu and click Start to get the board with the bombs (4 buttons as of now) Each button has either a bomb or a defualtbutton. I created my button so it can't be unselected. The problem is I have the button in a Class.java and I want that to close in a period of time. What do you recommend using?
/*
* 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.
*/
package battleship;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.GridBagLayout;
[code]....
I can call the clas in my main jFrame but I want to close the class after a certain time.
I have the following project:
Java Code:
package boxmatrics;
import java.awt.BorderLayout;
import java.awt.FlowLayout;
import javax.swing.JFrame;
public class BoxMatrics {
public static void main(String[] args) {
[code]....
Why I have to resize the window(JFrame window) manually, with the mouse, in order to see the components?Where do I need to call repaint(); ?
I trying to replace original (and empty) JPanel in JFrame with my own made one, components does no appear right, when I pass the mouse first button appears:
MainViewClass:
...
private void initComponents() {
...
MenujPanel = new MenuSuperior();
MenujPanel.setBorder(
BorderFactory.createTitledBorder("Dados Pessoais"));
[Code] .....
Here is the video:
my JFrame is not showing anything, (Perhaps test it in your own IDE on your own PCs/laptop)
// Project: RestaurantBillCalculator.java Calculates a table's bill.
// Import statements for different classes
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.JButton;
import javax.swing.JComboBox;
[code]....
I am trying to add scrollbars to my frame containing many different components and appearing when user resizes the window with the mouse adds pictures and admin of this online application adds labels or other components.
I want scrollbars to appear when the frame is resized and has components you don't see under so you can scroll down.
If I have for example this code, how i add the scrollbars when i make frame smaller ?
public class Test extends JFrame {
private JPanel contentPane;
/**
* Launch the application.
*/
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
[Code] ....
I am trying to use a JFrame to open up extra windows that will prompt the user the Log In or Out, but I am getting an error with one of my variables that writes to Excel. There is something wrong with the variable "sheet" contained in the "while(i <= 4)"
private void createLabel(WritableSheet sheet) throws WriteException
{
WritableFont times10pt = new WritableFont(WritableFont.TIMES, 10);
times = new WritableCellFormat(times10pt);
times.setWrap(true);
WritableFont times10ptBoldUnderline = new WritableFont(WritableFont.TIMES, 10, WritableFont.BOLD, false, UnderlineStyle.SINGLE);
[Code] .....
In one jframe i have insert one jfilechooser but when i open in second time jfilechooser when i want close...don't close.
When I close jframe i want destroy memory of jfilechooser... How to do???
For to close jframe i write:
jframe.dispose();
but don't to do nothing....
What is serialization in Java ?how to use serialization in Singleton?
View Replies View RelatedIf i am correct, a singleton class is the one for which only one object is allowed to create right. so why can't i just use everything in that as static and access them using the class name ? what is the need to create a single object ?
View Replies View RelatedI have heard about using patterns in core java.Is it possible?If yes, how?
View Replies View RelatedI've found following code for Singleton Implementation from this forum, I am having a difficulty of understanding following,
1. When Singleton instance will be created, ( From which call ) ?
2. What feature of Static Inner class allow object to be singleton ?
3. How Inner Class implementation is thread safe ?
4. What will happen if variable "instance" mark as non-static, Will it still grantee singleton implementation ?
Java Code:
public class Singleton {
// Note private constructor
private Singleton() {}
private static class SingletonInner {
private final static Singleton instance = new Singleton();
}
public static Singleton getInstance() {
return SingletonInner.instance;
}
} mh_sh_highlight_all('java');
I want to create a singleton for DirContext for LDAP configuration, hence i have used the initialize on demandclass holder idiom as shown below
public class SlmApplicationContext {
/**
* inner class to hold the instance.
*/
private static class Holder {
private static DirContext instance = new InitialDirContext();
}
/**
* Method to get the singleton instance of this class.
* @return SlmApplicationContext
*/
public static SlmApplicationContext getInstance() {
return Holder.instance; }
...
}
Now the problem is if i close the DirContext.close(), when the next request comes the singleton wont work as the dir context is already closed, hence it will create a new dir context for each requests. Which breaks the singleton concept, hence how we can ensure the singleton works fine even with DirContext.close()?
When I browsed I came to know two ways of implementing singleton.. I dont know which is best.. I am implementing this to load resource bundle only once for my jvm using constructor to getBundle.
public class bundle {
private final static Logger LOGGER = Logger.getLogger(bundle .class.getName());
private static bundle instance;
private static ResourceBundle messages;
private bundle () {
messages = ResourceBundle.getBundle("pb", Locale.getDefault());
[Code] ....
and I am calling this as bundle.getInstance.getMessage("hi");I wanted to knw which option is better and why.. and in the second case how can i call the getMessage() method?
In singleton pattern just having a static field is not enough? Do we really need to have a private constructor?
I can have a static field and have a public constructor and still say it is singleton.
My assignment was to create a simple form that demonstrates the use of the factory and singleton design patterns. "Use the Factory pattern to ensure that each form input consists of a text label and a textfield. Use the Singleton pattern for the submit button. When the submit button is clicked, a pop-up should show all the information that was typed into all of the form fields."
I used JFrame to create the form without the design patterns and I although I get the desired result, I'm not quite sure how I can integrate the design patterns into the code I wrote. The example I have to go off uses shapes, not text fields so I think that's why I'm not quite clear on how to approach this.
Here's my code so far:
import javax.swing.event.*;
import javax.swing.*;
import java.awt.*;
[Code]....
My assignment was to create a simple form that demonstrates the use of the factory and singleton design patterns. "Use the Factory pattern to ensure that each form input consists of a text label and a textfield. Use the Singleton pattern for the submit button."
Here's what I have:
Form.java file
interface Form {
public void getFormField ();
}
Name.java file (I have a similar files just like this for Address.java, City.java, State.java, Zip.java and Phone.java)
import java.util.Scanner;
class Name implements Form
[Code] ....
It compiles at the moment but I get a null pointer exception in the main method of the FormFactoryDemo file.
i've got this code that i cant get to work as i want it to. when its exported and i run it the file i wants gets created but when i open the file there is a single number like 999998000001
import java.io.IOException;
import java.io.PrintWriter;
public class mainHej {
public static void main(String arg[]){
[code]...
For every stream that we create for java i/o we write at the end in finally block
finally
{
if(is!=null)
{
is.close();
}
}
It works
my question is as per syntax in if (is!=null) this means that if is means stream contain some value then close it(!=null)
then how it in my opnion it should be like (in logical way)
if stream contain nothing then close it
if(is==null)
{
is.close();
}
I am confuse about working this line
So I have this line of code...
ioexception11.addChoosableFileFilter(new Jframe());
And when I compile it gives me...
error: constructor Jframe in class Jframe cannot be applied to given types;
ioexception11.addChoosableFileFilter(new Jframe());
how the entire application could be close when you click on X in a JDialog Box. I have tried
System.Exit (0)
but it only close the Dialog box