Mascaras

class FormataField extends PlainDocument {

		private int tamanhoMaximo;

		public TamanhoMaximo(int tamanhoMaximo) {
			super();
			this.tamanhoMaximo = tamanhoMaximo;
		}

		public void insertString(int offset, String string,
				AttributeSet attributteSet) throws BadLocationException {

			if (string == null) {
				return;
			}

                        String upperString = string.toUpperCase();
			if (tamanhoMaximo <= 0) {
				super.insertString(offset, upperString, attributteSet);
				return;
			}

			if ((getLength() + string.length()) <= tamanhoMaximo) {
				super.insertString(offset, upperString, attributteSet);
			}
		}
	}