JtextField input value

[daina]

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

[sjalle]

One way is to use try/catch

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.

[daina]

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);
}
}

[Norm]

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) {

[sjalle]

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.

[Norm]

Why wasn't the try{ }catch(){} catching the error?

[daina]

Hi Friends,

it worked. thanks for the help.

Regards
Diana