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Creating JPanels with a titled border in a for loop from user input

I want to create a for loop that creates JPanel containers with titled headers. the number of iterations depends on the user input from previous interfaces.
int noofpara=Integer.parseInt(data[6]);
for(int i=1;i<=noofpara;i++){
jPanel1.add(new JPanel().setBorder(new TitledBorder("Perimeter"+i)));
}
The noofpara is the number of perimeters the user chose according to that the for loop should create panels with the titled border with the number of perimeters. the error appears at the jpanel1.add... where it says void type not allowed.

JPanel#setBorder method has void return type, which mean it doesn't return any value when that method invoked.
But JPanel#add method need a value in order to invoked, it gives compilation error since setBorder is void.
You can simply fix this by this.
JPanel childPanel = new JPanel();
childPanel.setBorder(new TitledBorder("Perimeter" + i));
jPanel1.add(childPanel);

You have to make new panel and add.
for (int i = 1; i <= noofpara; i++) {
JPanel innerPane = new JPanel();
innerPane.setBorder(new TitledBorder("Perimeter" + i));
jPanel1.add(innerPane);
}

Generate many JPanel in runtime which contain a JList and a JButton

I have made an app, that so far places a food order to the system. After placing the order, the order details (Pizzas, drinks etc.) should appear in the chef's screen. This screen will consist of 1 JFrame which contains many JPanels(each of them contains a JList and a JButton). The number of JPanels appearing on the chef's screen has to be equal to the number of orders pending at the moment.
I do not know how to display the order in chef's screen by creating a new Jpanel every time a new order is placed.
Is there any way of doing that?
Thanks for your help in advance!

Assuming the number of orders at the time is num, you can do something like this:
frame = new JFrame();
frame.setBackground(Color.white);
frame.setBounds(20, 20, 800, 800);
frame.setLayout(null);
panels = new JPanel[num];
for(int i = 0; i < num; i++) {
panels[i] = new JPanel();
panels[i].setLayout(null);
panels[i].setBackground(Color.cyan);
panels[i].setBounds(100*i + 10*i, 0, 100, 100); // this is just an example; you can change these numbers
frame.add(panels[i]);
}
frame.setVisible(true);
and then add all the add all your order details into a JTextField and add the text field to the respective panel. Hope this helps!

Guess Number Game GUI - Infinite Loop

I'm making a guess the number program and I'm having trouble with my loop. When I run the program and input a number into the textfield and hit enter it freezes. I figured out that this might be happening because of an infinite loop. Feel free to correct me if I'm wrong. Basically when I enter a number into the textfield and press enter it suppose to change a label and change background color but this doesn't happen and I think its because my loop runs until win becomes true and when I type in my number it keeps running that number instead of outputting the correct label and letting me input a different number into the textfield. P.S: I know the newGame button does not work yet
import java.util.*;
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
public class GuessingGame implements ActionListener
{
JFrame guessFrame;
JPanel guessPanel;
JTextField guessText;
JButton newGame;
JLabel rangeLbl, enterGuessLbl, winLbl;
Random rand = new Random();
int numToGuess = rand.nextInt(1000)+1;
int numOfTries = 0;
int guess;
public GuessingGame()
{
// Create the frame and container.
guessFrame = new JFrame("Guess the Number");
guessPanel = new JPanel();
guessPanel.setLayout(new GridLayout(5,0));
// Add the widgets.
addWidgets();
// Add the panel to the frame.
guessFrame.getContentPane().add(guessPanel, BorderLayout.CENTER);
// Exit when the window is closed.
guessFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
// Show the converter.
guessFrame.pack();
guessFrame.setVisible(true);
}
// Create and add the widgets for converter.
private void addWidgets()
{
// Create widgets.
guessText = new JTextField();
guessText.setHorizontalAlignment(JTextField.CENTER);
rangeLbl = new JLabel("I have a number between 1 and 1000. Can you guess my number?", SwingConstants.LEFT);
enterGuessLbl = new JLabel("Please enter your guess", SwingConstants.LEFT);
winLbl = new JLabel(" ", SwingConstants.CENTER);
newGame = new JButton("New Game");
// Listen to events from Convert textfield.
guessText.addActionListener(this);
// Add widgets to container.
guessPanel.add(rangeLbl);
guessPanel.add(enterGuessLbl);
guessPanel.add(guessText);
guessPanel.add(winLbl);
guessPanel.add(newGame);
}
// Implementation of ActionListener interface.
public void actionPerformed(ActionEvent event)
{
boolean win = false;
guess = Integer.parseInt(guessText.getText());
if ( guess == numToGuess)
{
win = true;
}
else if ( guess < numToGuess)
{
winLbl.setText("Too Low");
guessPanel.setBackground(Color.red);
guess = Integer.parseInt(guessText.getText());
}
else if ( guess > numToGuess)
{
winLbl.setText("Too High");
guessPanel.setBackground(Color.blue);
guess = Integer.parseInt(guessText.getText());
}
winLbl.setText("Correct!");
guessPanel.setBackground(Color.green);
}
public static void main(String[] args)
{
GuessingGame game = new GuessingGame();
}
}

Your while-loop is inappropriate here, because you are in a actionPerformed() Method. This method is most likely to be called on a gui action (e.g. button kicked).
It should do one action corresponding to your needs and then terminate, since this method is invoked within the EDT. Your gui will not perform any updates until this method is finished.
Thus nothing will change (e.g. your win status) until the user makes some additional action, which he can't because your gui is frozen.

You don't update the value of guess. You'll need to read guess at the end of your loop, or at least in those cases that guess and numToGuess don't have the same value.
In the current case: if the values are not equal the first iteration, it will never become.
add
guess = Integer.parseInt(guessText.getText());
as last statement to each else if block
EDIT: a better way, as Marcinek points out, would be to remove the while loop, but since I don't know your requirements, I won't go as far as to claim it's the correct sollution.

Your loop keep runing because this condition if ( guess == numToGuess) never verfied
boolean win = false;
while (win == false){
if ( guess == numToGuess){
win = true;
}
.......
}
and
win still false, and while loop go a head runing.
while (win == false)
{
.....}

Error when I tried to run my Java class on another computer?

I am notdoing a school project, so please do not be alarmed. I am doing some private programming to brush up. My program, a program of type .java, creates a form that asks for the boundaries and quantities of a lottery-drawing activity and acts on the generating based on the input.
Here's my problem. On the WIndows 2000 computer where I coded the program, shows itself, perfectly. That's only half the story. When I tried to put it on another computer, the program shows a blank window; it compiles and runs, but it shows a blank window. Now, I do consider version numbers to be factors, so I will provide the versions and ask for confirmation if those are the root of the evil.
On my original computer, which is Windows 2000, the version is 1.6.0_31-b05. The other computer, which is Windows 7 dual-booted with Linux Mint 17.2, is running 1.8.0_60-b27 and 1.8.0_00 respectively.
My program is not finished yet, but I'll worry about that later. What I'm hoping to do now is to get the program, such as it is, to run on the platforms of all my computers. Since Java is known for its portability, I expect it to run on all my computers. Is that a misconception?
Anyways, here's the code:
//Import class libraries
import javax.swing.*;
import javax.swing.JOptionPane;
import java.awt.*;
import java.awt.event.*;
public class Lotterygui //Begin class
{
//VARIABLES FOR DATA COLLECTION
private JTextField lowerRange; //Lowest number
private JTextField higherRange; //Highest number
private JTextField quantity; //How many numbers to generate
private JTextArea displayArea; //What to display when the program is in use
//ADD WARNING CONSTANT FOR INVALID INPUT
private final String WARNING = "Please fill out valid data "
+ "and not leave anything out. "
+ "Also,do not enter any "
+ "zeroes.";
public Lotterygui()
{
//GUI CONFIGURATION
//Frame settings
JFrame jfrFrame = new JFrame("Lottery Program");
jfrFrame.setSize(300,400);
jfrFrame.setLocationRelativeTo (null);
jfrFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
jfrFrame.setVisible(true);
jfrFrame.setResizable(false);
//Panel to hold the user input controls in place
JPanel jplInputs = new JPanel();
jplInputs.setLayout(new GridLayout(4, 2));
//CREATE INPUT CONTROLS
//Lowest range
JLabel jlblLowerRange = new JLabel("Lowest");
lowerRange = new JTextField();
//Highest range
JLabel jlblHigherRange = new JLabel("Highest");
higherRange = new JTextField();
//Quantity
JLabel jlblQuantity = new JLabel("Quantity");
quantity = new JTextField();
//Buttons and their respective action associations
//Generate numbers button
JButton jbtnGenerate = new JButton("Generate");
ActionListener alGenerate = new listenGenerate();
jbtnGenerate.addActionListener(alGenerate);
//Reset all values button
JButton jbtnReset = new JButton("Reset");
ActionListener alReset = new listenReset();
jbtnReset.addActionListener(alReset);
//ADD CONTROLS TO FORM
jplInputs.add(jlblLowerRange);
jplInputs.add(lowerRange);
jplInputs.add(jlblHigherRange);
jplInputs.add(higherRange);
jplInputs.add(jlblQuantity);
jplInputs.add(quantity);
jplInputs.add(jbtnGenerate);
jplInputs.add(jbtnReset);
//CREATE DISPLAY AREA AND ADD
//The display area used for showing generated numbers
displayArea = new JTextArea();
displayArea.setLineWrap(true);
displayArea.setText(WARNING);
//The control that sets autoscrolling for the display area
JScrollPane jspDisplayArea = new JScrollPane(displayArea);
jfrFrame.add(jspDisplayArea);
//Add the JPanels to the window
jfrFrame.add(jplInputs, BorderLayout.NORTH);
jfrFrame.add(jspDisplayArea);
}//END lotteryGUI constructor
//MAIN Method
public static void main (String[] args)
{
//CALL UP lotteryGUI CLASS
new Lotterygui();
}//END Main method
//GENERATE BUTTONS ACTION
private class listenGenerate implements ActionListener
{
public void actionPerformed(ActionEvent e)
{
//DECLARE VARIABLES
int low; //Lowest number
int high; //Highest number
int qty; //How many numbers
try //Monitor the input of above variables in the form
{
low = Integer.parseInt(lowerRange.getText());
high = Integer.parseInt(higherRange.getText());
qty = Integer.parseInt(quantity.getText());
}
catch (NumberFormatException nfe)
{
//RESET ALL FORM VALUES
reset();
//RESET VARIABLE VALUES
low = 0;
high = 0;
qty = 0;
}//END format errors try-catch
//CHECK IF PROGRAM CAN CONTINUE
if (low != 0 || high != 0 || qty != 0) //If valid
{
//Action pending
displayArea.setText("Generate here - incomplete");
}
else //If there are more one or more errors in the input
{
//ISSUE WARNING
JOptionPane.showMessageDialog(null, WARNING);
}//END IF continue CHECK
}//END actionPerformed method
}//END listenGenerate class
I've been looking up and down at the code. Can this that I did not reference any of the layouts outlined in import? I know it's not JPanel as I did try that can still the problem existed. Anything that will help me will be appreciated. Thank you.

You're calling
jfrFrame.setVisible(true);
first and then adding a bunch of components to the JFrame, and that's backwards and can result in a GUI that does not render components until it is resized or minimized and restored. In fact try this -- run your program, then minimize the blank GUI and restore it, and I'll bet you'll see your components.
I suggest that you swap this order around -- call jfrFrame.setVisible(true); last after adding everything to the GUI.

Dynamically generated jbuttons

I'm trying to make a GUI for that simulates elevators in a building (really to test threading/c-scan), but when generating the buttons for the elevator control panel and the buttons for each individual floor, I'm kind of stuck. I thinking about trying to generate a new pair of buttons for each floor, and generating a new control panel per elevator. Also there's the difficulty of having a variable amount of floors. Anyway my question what is this best way to go about doing this? Perhaps it's not necessary to generate new buttons for everything and just use one set and change what the actions do per floor/elevator? I'm asking because I'm not very familiar with GUIs. Thanks for the help

If all the elevators, and the control panel are the same, you can use a singular method and pass in the elevator or the control panel. CustomPanel extends JPanel and has a method foo.
public void createElevatorButtons(final CustomPanel panel) {
ArrayList<JButton> buttons = new ArrayList<>(); //arraylist of buttons we can keep track of
JPanel buttonPanel = new JPanel(); //the visible component
for(int i = 1; i <= numberOfFloors;i++) {
JButton button = new JButton(String.valueOf(i)); //creates buttons for floors 1 to max
buttons.add(button);
buttonPanel.add(button);
}
panel.add(buttonPanel);
//add the action listeners
for(JButton button : buttons) {
button.addActionListener( new ActionListener() {
public void actionPerformed(ActionEvent e) {
JButton floor = (JButton) e.getSource();
int floorNumber = Integer.parseInt(floor.getText());
panel.foo(floorNumber); //we tell the elevator/panel/whatever to do something, you will have to extend JPanel to do foo
}
});
}
}

In this case that the number of floors is variable you can create an array of buttons:
JButton[] buttons = new JButton[MAX_NUMBER_OF_FLOORS];
Then when you determine the exact of number of floors at runtime, you can go to instantiate and add the buttons:
for(int i=0; i<numberOfFloors; i++) {
buttons[i] = new JButton();
controlPanel.add(buttons[i]);
}
Something like this should work.
Assign MAX_NUMBER_OF_FLOORS a big number like 100, there should be a possible limit given by the problem.