import javax.swing.JTextField;
import javax.swing.text.AbstractDocument;
import javax.swing.text.AttributeSet;
import javax.swing.text.BadLocationException;
import javax.swing.text.DocumentFilter;
import javax.swing.text.JTextComponent;
public class Main {
public static void main(String[] argv) {
JTextComponent textComponent = new JTextField();
AbstractDocument doc = (AbstractDocument) textComponent.getDocument();
doc.setDocumentFilter(new FixedSizeFilter(10));
}
}
class FixedSizeFilter extends DocumentFilter {
int maxSize;
public FixedSizeFilter(int limit) {
maxSize = limit;
}
public void insertString(DocumentFilter.FilterBypass fb, int offset, String str, AttributeSet attr)
throws BadLocationException {
replace(fb, offset, 0, str, attr);
}
public void replace(DocumentFilter.FilterBypass fb, int offset, int length, String str,
AttributeSet attrs) throws BadLocationException {
int newLength = fb.getDocument().getLength() - length + str.length();
if (newLength <= maxSize) {
fb.replace(offset, length, str, attrs);
} else {
throw new BadLocationException("New characters exceeds max size of document", offset);
}
}
}