table.addKeyListener(new KeyListener() {
public void keyPressed(KeyEvent e) {
if (e.getKeyCode()==KeyEvent.VK_ENTER) {
model.addRow(new Object[]{"", "","",""}); } }
public void keyReleased(KeyEvent e) { }
public void keyTyped(KeyEvent e) { } } );
I've added JTable to JPanel and used DefaultTableModel. I have to add a new empty Row to table after i press enter key. But somehow I've not been successful so far.
I am learning Java on my own, and I am creating little programs to do so.The program below asks the user to input text and hit enter. When user does that, it asks if that is correct. If the user enters "y," the program ends. That's good.If the users enters "n," the strGrategul is set to empty which triggers the while statement to start over again. That's good. However, when the program asks the user to "Tell me one thing you are grateful for..." it doesn't wait for user input. Instead it skips to "You said ''? Enter 'y' or 'n'" It thinks the user enter an empty line.
When i run my program i see a JTable with data in it. The first 3 columns are filled with data, the next one is empty. Other columns that come afther the empty one are also filled.
So my 4th column is empty. But it only apears empty, cause when i move the 4th column to the left. The same column that was at 4th place is now at 3th place and filled up with data.
So the 4th column apears empty but it contains data when i move it to the left or the right.
Why does it show an empty column at the 4th place?
Some printscreens to get it clear:
In attachment:
attachment1 = 4th Column is empty attachement2 = 4th column is moved to 3th place and is filled with data.
I am designing a advanced search option in a java project with sqlite in NetBeans. there are 5 different JTextfields and 5 columns, I want to populate JTable with corresponding matching criteria. If a JTextfield is empty then it should select all items of that column.
query i was using is: String val1=txt_billing2.getText(); //five input fields String val2=txt_station2.getText(); String val3=txt_invoice2.getText(); String val4=txt_amonth2.getText(); String val5=txt_umonth2.getText();
[code]....
but when i leave a JTextfield empty it shows no data in JTable. only method i know is to use if else conditions but that generates 5!= 120 conditions!!!
I have an empty string and I want to add to it crosses and naughts. I want to simulate a board of TicTacToe game. My goal is print out 5 strings like this : "xox xxx oxo". There are 3 groups of symbols separated with a space. The crosses and naughts are filled randomly.
Random rand = new Random(); char[] characters = new char[] { 'x', 'o' }; int numOfTimes = 0; while (numOfTimes < 5) { String board = ""; String space = " "; for (int group = 0; group < 3 ; group++)
I have a JTable that is being used to display, and edit data from a database. When the user presses the Enter key on the keyboard I want a carriage return to occur in the cell they are typing in. I do not want the cursor to go to the next row which is the default behavior.
I have a 30 X 10 JTable which i would like to put a border around some cells and change Background colors on others.For example i would like to put a border around cells 1,1 to 15,1 I would like to change background colours on several individual total cells.What the shortest way to color individual cells and add a border?
I'm trying to fill my jtable with an arraylist. The problem is the jtable is in an extended class and the arraylist in the mainGUI. Now how can I fill the jtable with the arraylist?
That's the arraylist in my MainGUI
BufferedReader in = null; ArrayList<String> data = new ArrayList<String>(); try { in = new BufferedReader(new FileReader("1.dat.txt")); String str; while ((str = in.readLine()) != null) { data.add(str);
I want to use JTable in which the user can enter the obtained marks of students and automatically add (total) the obtained marks in the total column. The structure of the table is given below.
How to improve my code. I finally was able to create a program that gives you the corresponding letter grade, when you enter in a numeric grade without using an array. The only issue left is that I have to be able to enter 5 grades at a time, and it give me the letter grade for all 5. I have the programming working, but only am able to enter 1 at a time. I am not sure what kind of loop or if I am supposed to use a loop.
public static void main(String[] args){ { int grade = 0; Scanner input = new Scanner(System.in); System.out.println("Enter : "); grade = input.nextInt(); if (grade >= 90)
I am having some troubles with a program fileviewer where you must be able to change font style and size when pressing JButton "Set font". I have solved the most of the program and every menu button is working but I don't know how to set in FileListener class method to change the font when running in main class. Anyway, this is my FileListener class
Java Code:
import java.awt.*; import javax.swing.*; import java.awt.event.*; import java.io.*; import java.util.*; import java.awt.Font; public class FileListener implements ActionListener
import java.util.Scanner; public class Program08 { public static void main(String []args) { char q; int quit = 0;
[code].....
I'm trying to get the code to repeat after the do part and before the while statement. Then press 'q' to quit the program. I had it right earlier by getting the program to repeat if you did a binary number, but I keep messing it up more and more.
I don't get what I missed in the code. I used the example of changing the text of a button by clicking on it, but instead I also added a JLabel and tried to make the button change its text instead, but it didn't work. What did I do wrong?
i just started java and I'm trying to change the JLabel text by clicking on the JButton however it isn't working,
import java.awt.BorderLayout; import javax.swing.JFrame; import javax.swing.JButton; import javax.swing.JLabel; public class BorderLayoutJFrame extends JFrame { public static final int WIDTH = 400; public static final int HEIGHT = 400;
Problem: On the form window, after pressing the button, it doesn't give any error and doesn't give any output. It doesn't reply and i have to stop compiling to exit. Why does the IDE do that, is it about my Java codes or Form Window codes ? ( I have two classes named Lexical.java and window.java. Working with Eclipse)
Details: I am working on a project that makes Lexical and Syntax analiysis of commands written in SQL Language. My form is in the attachment. If will be necessary i'll put my codes too.
I am learning how to program in JAVA servlet+MySQL. Decided to make a simple program where it shows who is celebrating birthday today by retrieving data from database. At the moment I managed to get it working by loading a form.html and pressing the button in it which gets to the result.jsp and shows results there.
My plan was to get a list of people who are celebrating there birthdays initially when the website is loaded/being loaded, I mean when you enter URL into your web browser and you get it instantly in browser. Is there a way to do it the way I want (JAVA+servlet+MySQL) instead of pressing a button/link?
I have a HashMap with multiple values at runtime. In that map one key has empty value , how to avoid this value to add in a list. some code sample is below:
public HashMap getLoop2Map(Map map, String xslFile , int sheetNo){ HashMap hashMap = new HashMap(); try{ ArrayList list = new ArrayList(); System.out.println("-------Map : " +map); list.add(map.values()); //System.out.println("------- boolean : " +val); System.out.println("------List : " +list); }
I do not want to add the empty value in a list ...
result in map
-------Map : {Free Text Entry={}, Mouth / Throat={Free Text Entry={Free Text Entry=<FORMFILENAME>EditChartPhysicalExamText.form </FORMFILENAME><TAG>"<MUSCULOSKELETAL.PE>"</TAG>}, Salivary Glands Condition={Salivary Glands Condition=MouthAttribute}, Examination Overview- Mouth / Throat={Examination Overview- Mouth / Throat=MouthAttribute}, Tonsils={Tonsils=MouthAttribute},
@ManagedBean @SessionScoped public class HelloBean { public void downloadFile() { File file = new File("C:datacontacts.doc"); HttpServletResponse response = (HttpServletResponse)
1) productType that have name and price of the productType and an empty consturcor. 2) superMarket that have name of supermarket and arraylist of productTypes (
private ArrayList<ProductType> products;
) and an empty constructor.
In each class I have function that get input from console and should store it into each class variables.
In productType i have function:
public void getFromUser() throws IOException { BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); System.out.println("Enter product name:"); name = br.readLine(); System.out.println("Enter price:"); price = Integer.parseInt(br.readLine());
[Code] ....
The main is something like:
public static void main(String[] args) throws IOException{ SuperMarket s1 = new SuperMarket(); SuperMarket s2 = new SuperMarket(); s1.getFromUser(); }
The problem is when i get to line "products.add(i,p)" I get java.lang.NullPointerException
In the debug mode I can see that when I get to this line the "products" is null.
why do you think this happening, when I do "new SuperMarker()" in the main it should run the empty constructor and create new arraylist...
I've been beavering away with Java for a few months. But as with all languages the String implementation looks designed to trip up even experienced programmers.
My current development gets data from various sources outside my control. When I get a string I want to test if it is empty/null/or whatever. Simple enough one thinks.
But if you search the internet you see everone seems to have a slightly different approach. So what is the best way of determining that a string is not useful to you?
I've had success with this
if(string == null || string.length() == 0)
But I've seen people using methods - not necessarily of String (e.g equals, empty) and regular expressions.
What is the best approach to this considering coding efficiency and/or processing efficiency (accepting you'd have to be processing a lot of strings for the latter to be an issue).
im trying to make a gui im trying to add a new jbutton for every empty cell in the array, and for some reason its giving me array index out of bounds error, this is what i have, im trying to to do it in an 80 by 80 array.
public JButton[][] buttons = new JButton[80][80];
public void addButtons(){ for(int i=0;i<buttons.length;i++){ for(int j=0;i<buttons[i].length;j++){ buttons[i][j]= new JButton(); } }
I'm writing basically my first program for school. I've written small ones, following instructions, but this is the most vague. I'm having issues. I can't figure out what the error means. I'm not done with the code, but I think the ArrayList is throwing me off. I'm trying to gather user input and sum the total. Here's the code:
package graduationplanner; import java.util.ArrayList; import java.util.Scanner; import java.lang.Double; public class GraduationPlanner { public static void main(String[] args) {
I am having issues with the program below everything works but I can't figure out a way to add code that if a user just hits enter without inputting anything it says "entering in nothing is not a valid choice" I am stuck on how to compare a int to a string ...
//import statements import java.util.*; //for scanner class // class beginning public class Guess { public static void main(String[] args ) { //Declare variables area
