Question

How i can do a simple pattern matching in blackberry OS 6.0. The purpose is to check whether the user name entered to the UserName edit field contains special characters…. plz help me
thanks jibysthomas

Answer 1

A better solution would be to control the user input by adding an appropriate TextFilter to your edit field. That has the added benefit of modifying the on-screen keyboard to match your filter on those devices so equipped.

Here is an example combining the action of two built in text filters to make one that only allows upper letters and numbers:

import net.rim.device.api.ui.text.TextFilter;
import net.rim.device.api.system.Characters;

/**
* A TextFilter class to filter for station identifiers
*/
private static class StationFilter extends TextFilter {

 // Order of the supporting filters is important, NUMERIC will convert
 // letters to numbers if it gets them first.
 private static TextFilter[]      _tf = {
  TextFilter.get(TextFilter.NUMERIC),
  TextFilter.get(TextFilter.UPPERCASE)
 };

// Convert using the first supporting filter that has a conversion
 public char convert( char character, int status) {
  char c = 0;

  for (int i = _tf.length - 1; i >= 0; i--) {
   c = _tf[i].convert(character, status);
   if (c != 0) {
    return c;
   }
  }

  return 0;
 }

// Validate a space for separator, then by supporting filter
 public boolean validate(char character) {
  if (character == Characters.SPACE) {
   return true;
  }

  for (int i = _tf.length - 1; i >= 0; i--) {
   boolean b = _tf[i].validate(character);
   if (b) {
    return true;
   }
  }

  return false;
 }
}