JtextField input value


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Thread: JtextField input value

  1. #1
    Join Date
    Sep 2005
    Posts
    22

    JtextField input value

    Hi Friends,

    I am new to java.Can u Plz help me.I would like to know if there is any way to check if user input into a JtextField is numeric or not. There does not seem to be a method available that is similar to VB's IsNumeric.

    Thanks
    Diana

  2. #2
    Join Date
    Nov 2004
    Location
    Norway
    Posts
    1,560
    One way is to use try/catch

    Code:
    try {
      int i=Integer.parseInt(txtF.getText().trim());
    } catch (NumberFormatException e) {
      System.err.println(txtF.getText().trim()+" is not an integer");
    }
    Note: when converting string values to numeric you must get rid of any leading/trailing
    blanks, use the trim() method of the String class for that.
    eschew obfuscation

  3. #3
    Join Date
    Sep 2005
    Posts
    22
    Hi
    it is working. but when ever i run the program in the console this is printing


    java.lang.NumberFormatException: For input string: "b"
    at java.lang.NumberFormatException.forInputString(NumberFormatException.java:48)
    at java.lang.FloatingDecimal.readJavaFormatString(FloatingDecimal.java:1213)
    at java.lang.Float.parseFloat(Float.java:204)
    at com.icope.application.ItemDetails.actionPerformed(ItemDetails.java:244)
    at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1764)
    at javax.swing.AbstractButton$ForwardActionEvents.actionPerformed(AbstractButton.java:1817)
    at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:419)
    at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:257)
    at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:245)
    at java.awt.Component.processMouseEvent(Component.java:5134)
    at java.awt.Component.processEvent(Component.java:4931)
    at java.awt.Container.processEvent(Container.java:1566)
    at java.awt.Component.dispatchEventImpl(Component.java:3639)
    at java.awt.Container.dispatchEventImpl(Container.java:1623)
    at java.awt.Component.dispatchEvent(Component.java:3480)
    at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:3450)
    at java.awt.LightweightDispatcher.processMouseEvent(Container.java:3165)
    at java.awt.LightweightDispatcher.dispatchEvent(Container.java:3095)
    at java.awt.Container.dispatchEventImpl(Container.java:1609)
    at java.awt.Window.dispatchEventImpl(Window.java:1590)
    at java.awt.Component.dispatchEvent(Component.java:3480)
    at java.awt.EventQueue.dispatchEvent(EventQueue.java:450)
    at java.awt.EventDispatchThread.pumpOneEventForHierarchy(EventDispatchThread.java:197)
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:150)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:144)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:136)
    at java.awt.EventDispatchThread.run(EventDispatchThread.java:99

    is there is any way to avoid this. My code is
    public void actionPerformed(ActionEvent event) {

    try {
    float priceItem=Float.parseFloat(price.getText().trim());

    } catch (NumberFormatException e) {
    JOptionPane.showMessageDialog(this,"Invalid Entry. Try again ", "Error Message", JOptionPane.ERROR_MESSAGE);
    price.setText("");

    }
    if(event.getSource() == Save){

    if(PriceItem.length()==0) {
    JOptionPane.showMessageDialog(this,
    "Please Enter the Price", "Error Message",
    JOptionPane.ERROR_MESSAGE);
    }
    else if(price1 <=0 ) {
    JOptionPane.showMessageDialog(this,
    "Price cannot be Less than or Equal to 0.", "Error Message",
    JOptionPane.ERROR_MESSAGE);
    price.setText("");

    }
    else if(reorderlevel.length() ==0){
    JOptionPane.showMessageDialog(this,
    "Please Enter Reorder Level", "Error Message",
    JOptionPane.ERROR_MESSAGE);
    }
    }
    Last edited by daina; 09-26-2005 at 06:06 AM.

  4. #4
    Join Date
    Jul 2005
    Location
    SW MO, USA
    Posts
    299
    Is the following code you posted at line 244 in ItemDetails? (ItemDetails.java:244)

    try {
    float priceItem=Float.parseFloat(price.getText().trim()) ;

    } catch (NumberFormatException e) {

  5. #5
    Join Date
    Nov 2004
    Location
    Norway
    Posts
    1,560
    Test for save button first, if ok then get trimmed string->number value, if exception
    then repromt for correct entry, if not then set priceItem value.
    Repeat for other numeric values or make a method for it.
    Last edited by sjalle; 09-26-2005 at 09:50 AM.
    eschew obfuscation

  6. #6
    Join Date
    Jul 2005
    Location
    SW MO, USA
    Posts
    299
    Why wasn't the try{ }catch(){} catching the error?

  7. #7
    Join Date
    Sep 2005
    Posts
    22
    Hi Friends,

    it worked. thanks for the help.

    Regards
    Diana

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