Swing/AWT/SWT :: Restricting Data Entry In TextFields
Mar 4, 2015
I'd like to know is there a way to restrict a user from inputting certain characters into a TextField? Is there something like isNumeric() available?
In Visual Basic, I was able to prevent the user entering certain characters of my choice into each textbox, however I've looked and I haven't been able to find a solution. I've tried using the following else if as part of an if statement:
else if (txtEmployeeName.getText().contains("[0-9]+"){ }
I have a bunch of textboxes in a panel and I wanted to perform the same code when the user clicks into a textbox (select all the text in it). Right now I've started adding a focusgained listener to each textbox like this:
Is there a way I can have one focusgained listener that all the textfields can point to but have it pick the right textfield in the textFieldx.selectAll();?
As stated in the subject I'm a newbie when it comes to Java Programming (I'm in my second week of class). I'm trying to create a Retail Calculator for a class and need to multiply two values together (Price, Discount) in order to get the sale's price when the user hits a Calculate button. The price and discount are user input values from textfields in the beginning of the code.
public void actionPerformed(ActionEvent e) { String price; String discount; float salePrice; //Get the original price from price textfield price = priceValueField.getText();
I have an env-entry defined in my web.xml and when I attempt to print it from a simple servlet all I get is null. And of course if I attempt to invoke any methods on the object I get a NullPointerException.I read somewhere that this can happen if you're using version 2.4 instead of 2.5, so I changed to 2.5 and I still have the same issue. Here's the web.xml:
I'm using Ubuntu. After unpacking the tar file for JSE 1.7 version 45, in the the bin directory for adding an entry to PATH variable, I typed
javac
and I get the message
The program 'javac' can be found in the following packages: * default-jdk * ecj * gcj-4.6-jdk * gcj-4.7-jdk * openjdk-7-jdk * openjdk-6-jdk Try: sudo apt-get install <selected package>
If I get the bytecode with javap it seems to work:
Java Code:
Exception Table from to target type 26 30 40 any mh_sh_highlight_all('java');
But the problem is that I can't run the file anymore. Simply running it with the java command results in "java.lang.VerifyError: Expecting a stackmap frame at branch target 40". After some research this seems to be a problem with java 7 and a stricter verifier. I read several times that java -XX:-UseSplitVerifier should be used instead.
This really fixed the stackmap error, but then another error appeared: "java.lang.VerifyError: (class: AClass, method: signature: ()V) Inconsistent stack height 2 != 1". Are there any further steps required to insert a new exception in the exception table?
Additional info: Later I want to remove gotos (in this case the goto at line 27) and add a function call instead. When this function finishes it will throw a exception and propagate it back to the caller (which will be at line 27). Then the program should go on as if nothing happend, that is also the reason why the target of the exception is the same as the target of the goto (40)
and the corresponding snippets of the Java code are:
// Class member variables // ... private String product; private ArrayList<String> productValues; private ArrayList<String> productLabels; private SelectItem[] products; // ... Various properties etc. public String getLocation() { // Displayed on a page
[code]....
Most of this works correctly using only ArrayList SelectItem products without the two ArrayList and the separate SelectItem[], and the values and labels are put directly into products here. The menu works and I can select an item. However, I am unable to find the correct method for finding the index in the submit method,namely:
public void submit(ActionEvent e) { showProduct = true; prodNum = products.indexOf(product); // --- Here is the problem! updateProduct(); }
which has not been changed here. In spite of trying out various ideas, prodNum always returns with -1, which means it cannot find the index of the selected product, where product is a String. Everything else seems to work correctly, and products.get(prodNum).getLabel() works if I manually give prodNum a valid index, but because it's -1 it fails.
Is it possible to launch windows, specifically 8.1, directly into a java based program which would serve as the password entry screen? That is to say, instead of using the standard windows screen, could a java based alternative be used?
I have the source code used on jurassicsystems.com. I would absolutely kill to have a tweaked version of this system act as my password entry screen. It is literally something Ive wanted to have done for ages, and this emulation finally means it may be possible.
I have a list of 100,000 + names and I need to append to that list another 100,000 names. Each name must be unique. Currently I iterate through the entire list to be sure the name does not exist. As you can imagine this is very slow. I am new to Java and I am maintaining a 15+ year old product. Is there a better way to check for an existing name?
I am trying to get the data entered in a JTextField into a JTable but not clear on how. The LeftPanel is where the button is located and the RightPanel is where the JTable is. I want the actionPerformed to update the row of the JTable but I can't figure out how. There is another class that controls the GUI but did not think it was necessary to include. Also, I am aware that I am getting an error at the addRow line, can't seem to alleviate it.
public class LeftPanel extends JPanel {
private static final long serialVersionUID = -2311952438693382407L; private RightPanel rPanel; public LeftPanel(){ Dimension size = getPreferredSize(); size.width = 250; setPreferredSize(size);
I have been trying to learn a bit about JTables for a project I want to undertake. I have created a new JFrame in netbeans and added a button. Onclicking the button I want add some data to a JTable model and then output the JTable with the data. When I click the button again I want the same process to happen again and overwrite the previous table being displayed.
The problem I have is that when I click the button for a second time the table stays on the screen exactly as it did following the first click. I can see that the data in the model is changing so I am not sure why a new JTable is not drawn.
Trying to make a swing box where you can type in string data to the text field and a button. I want the string data to be added to a list everytime you press the addbutton.
I have a client server application. The UI for the server contains a JTable and in each row, details of the connected client are shown. Say if I have 5 connections and the 3rd connection disconnects, I need the 4th and 5th connection details to be displayed in 3rd and 4th row respectively. Can this be done?
I'm doing a project in which I must display prices of computer accessories in a Scroll Pane viewer. The if statements are all checkboxes. I am completely lost with how to print to the viewer if a checkbox is selected. Furthermore, I am also lost with how to add up all of the checkboxes.
private void USBCheckActionPerformed(java.awt.event.ActionEvent evt) { // TODO add your handling code here: double area = 0; double computerprice = 500.0; if (printerCheck.isSelected()){ double printer = 100.0;
i need to display the data from an xml file in a DefaultTableModel using the addRow method. in my table there are three columns named "symbol", "info" and "value", so i must create arrays of string objects from nodelists and insert them in the model with something like - addRow(new Object[] { getSymbolData, getInfoData, getValueData } ); but im stuck and cant seem to get it right.
I am trying to make a program where a user can enter guests name for a hotel, the JTable includes rows for the name of the tenant, the room number, month etc.
I've made the table, however I am having some trouble in saving the data that I put into the table. I used jtextfield and a jbutton to but data into the jtable. I am trying to save the data, and load it just buy clicking a button.
table.setModel(new DefaultTableModel( new Object[][] { }, new String[] { "Room", "Name", "Month", "Payment"//table rows } ));
This is my basic table. And what I'm trying to do to save the data is:
DefaultTableModel model = new DefaultTableModel(); private JFileChooser myJFileChooser = new JFileChooser(new File(".")); private void saveTable() { if (myJFileChooser.showSaveDialog(null) == JFileChooser.APPROVE_OPTION ) { saveTable(myJFileChooser.getSelectedFile());
[Code] ....
When I run my program, I'm able to click on a button, and the dialog box will appear, I'm also able to save the data to a file. However when I click on the retieve data button I made the dialog box opens, the file is there, however when I click it, nothing happens.
Java/Swing dialog box appears on the user's screenIt allows the user to enter 2 values into labelled text fields (fname/sname)They select a "Click Me" push button which I hope will write the data into the table. But the table does not get refreshed.
If I minimise the dialog box and then open it again, the data still does not appear.
The code I originally built using eclipse/WindowBuilder. I've cut it back and tried to isolate the issue. But I still cannot figure it out.
I've added some diagnostic log messages to ensure that I am seeing the various events I think I need to see and have put code in the action callbacks etc.
I am getting datas from user and checking it with database (MS SQL ) if it fits it is sweatching to new window. In new window I need to use again my database so I need to add connecting datas again. I would like to get them from login window. How to do that? I know theory but when I am writting code nothing works. Here is working code for login panel :
/*import java.awt.BorderLayout; import javax.swing.*; public class Login extends JFrame { public String url; public static void main(String[] args) { Log frameTabel = new Log();
I was trying to run an sql query to display onto my jtable. However, i got this as a result:
oracle.sql.CLOB@11876a2
When I run the same SQL query on Toad i get the field hugeclob and one is then able to see whats inside the field. I want to basically either have a hugeclob on my jtable or perhaps to display on a textarea the data
i am relatively new to Swing. learning swing concepts for my new project. how can we construct a Hierarchical JTable structure using Swing. Something like a Master-Child table structure with a drill down from Master table to Child Table. Something similar to the image Telerik.
I have seen some examples like TreeTable. But that is not what i am looking for. The Column headings for Master table and child table might differ.
how a JTable and respective DB table would be updated via directly editing a JTable: After table cell is updated, the setValueAt method of my custom TableModel is called to change the value of the data vector (assume I'm using vectors to store data). setValueAt then calls fireTableCellUpdated which updates the table view, and calls my custom TableModelListener.tableChanged method. Here is where I would write code to update the database.
This means an Update statement is fired each time a cell changes. Sometimes I would like to only send the Update after the entire record has been updated (and a user clicks a Save button).
But is not working. I was thinking may be API is not work with java 7 because i got the following warning (AudioStream is internal proprietary API and may be removed in a future release);
I have a tree-based data structure that looks somewhat like this:image1.png..Every tree always has a height of no more then 3, and each of these classes has a very specific use, generalization is not possible between them.Now, I want to display my data structure with a JTree in a Swing application. A JTree needs a TreeModel and so I created a custom TreeModel for my classes, it looks like this:
public class CustomTreeModel implements TreeModel { private Root root; public Object getRoot() { return root;
[code]....
But then I would introduce this interface to my Model classes just for the purpose of writing the View. So my data model has to be altered to make the View work, this sounds completely against MVC to me and also like something I dont really like.On the other hand, the CustomTreeModel would be much simpler, easier to understand, easier to maintain and just in general more pleasing to the eye.Should I change my Model to improve the View? Is instanceof okay to be used in View classes?
