Use the nio package instead : import java.nio.file.Files; import java.nio.file.Path; import java.nio.file.Paths; Path p = Paths.get(“/tmp/.minecraft”); if(!Files.exists(p)){ Files.createFile(p); } if(Files.exists(p)){ Files.delete(p); } 10 solved Java: Delete a file starting with “.” [duplicate]
All the code used to initialize the table model shouldn’t be part of its constructor. Don’t create a class extending DefaultTableModel, and don’t use static variables for the data and columns: you don’t want all the instances of your model to share a unique data vecstor and a unique columns vector. Move all this code … Read more
Why are you creating new instance of JButton in roll? You just need to change the icon of the buttons which are already displayed on the screen This… public void roll() { value = nextValue() ; if (value==1){ Icon i=new ImageIcon(getClass().getResource(“1.png”)); c= new JButton(i); add(c); } else if(value==2){ Icon im=new ImageIcon(getClass().getResource(“2.png”)); c= new JButton(im); add(c); … Read more
For db Add indexes for frequently searched fields Think about table partitioning, rarely searched data should be stored in archive tables For backend Optimize queries Minimize cursor fetching For client Use pagination to avoid large data loading Use async loading (SwingWorker for swing, Service for javafx) to avoid UI hanging Don’t mix archive and working … Read more
The following is a suggested implementation, also incorporating the good guidance you got from Frakcool: import java.awt.BorderLayout; import java.awt.Color; import java.awt.Dimension; import java.awt.Graphics; import java.awt.Graphics2D; import java.awt.GridLayout; import java.awt.Point; import java.awt.event.ActionListener; import java.awt.event.MouseAdapter; import java.awt.event.MouseEvent; import java.awt.geom.Ellipse2D; import java.awt.geom.Rectangle2D; import java.util.HashMap; import java.util.Map; import javax.swing.ButtonGroup; import javax.swing.JFrame; import javax.swing.JLabel; import javax.swing.JPanel; import javax.swing.JTextArea; import javax.swing.JToggleButton; … Read more
The image I need has to move around the screen An important piece of information missing in the original question. I don’t have a problem using a null layout for this. I wanted to move around with arrow keys on the screen? And don’t use a KeyListener for this. Instead you should be using Key … Read more
Don’t make the print method static. You need to call this after the user has made a file selection, passing in the file contents… Don’t create a new instance of the PrintText in the print this is not sharing the results of the file selection with the print method. Make sure you are honoring the … Read more
Your current approach is indeed not easily generalizable. The hard-coded parts of the buttons for “blue” and “green”, and especially the special methods like blueToGreen make it impossible to extend the number of colors with reasonable effort. (You don’t want to create methods blueToYellow, blueToRed, blueToTheThirdColorFromThisListForWhichIDontKnowAName …). There are many possible ways of generalizing this. … Read more
If I don’t define dimensions, how do I ensure the whole background I’m painting is displayed? You could use a JLabel to display the ImageIcon. The size of the label will be the size of the image. You then set the layout manager of the label so you can add components to it. Edit: do … Read more
Since you edited the question and clarified that you are using a JTextField I will reorder the answer: You don’t see any output because the action command has not been set so there is nothing to display. Try using the following in your ActionListener: JTextField textField = (JTextField)e.getSource(); System.out.println( textField.getText() ); Of course this will … Read more
Use the filtering support provided by JTable. Read the section from the Swing tutorial on Sorting and Filtering for more information and examples. 4 solved How to edit Rows in an Abstract Table Model
There are two basic approaches, the both kind of follow the same basic concept… Generate a list of images and paint them… You Could… Create a custom component which is singularly responsible for painting a single card. The benefit of this is that it’s generally easy to manage and uses what is already available. The … Read more
Your problem is that you don’t use correct architecture pattern. You should separate your business logic from your presentation. Also you should store variables (like time_left) in model, not in the controller (i.e. ActionListener). Please read about: Model View Controller pattern. It’s a basic pattern and it’ll solve most of yours problems. Basic Example Editor.java … Read more
There is no generic onChange function. However there is a method you can define in a class that implements KeyListener which is public void keyPress. You would use this something like the following: public class MyClass implements KeyListener { private JTextField myField; private JLabel myLabel; public MyClass() { myLabel = new JLabel(“Enter text here”); myField … Read more
Color oldColor = myButton.getBackground(); myButton.setBackground(Color.RED); // … do stuff myButton.setBackground(oldColor); 2 solved How to get back the original look and feel color of a button after changing its color? [closed]