How to limit JTextArea Rows and Coloums

Question

Hello
I am using JTextArea inside JScrollPane
I want to limit the maximum number of lines possible and the maximum chars in each line.
I tried to limit the lines but i don't know exactly how many lines do i have because of the line wrapping,
The line wrapping is starting new line in the screen but in the string of the component it is really the same line with no '\n' to indicate new line.
I need that the string will be exactly like on the screen, each line will end with '\n' (if there another line after it) and the user will be able to insert only X lines and Y chars in each line.
Does anyone have an idea?
Thank you in advance
Yuval

Answer 1

I wrote something similar but it is not enough
This is good only for the lines and not for the max chars in the lines
I tried something like this in class that extended the DefaultStyledDocument and :
private JTextArea textArea ;
textArea  = new JTextArea(3,19);
textArea  .setLineWrap(true);
textArea .setDocument(new LimitedStyledDocument(3));
JScrollPane scrollPane  = new JScrollPane(textArea );
public class LimitedStyledDocument extends DefaultStyledDocument {
    /** Field maxCharacters */
    int maxLines;
    public LimitedStyledDocument(int maxLines) {
        maxCharacters = maxLines;
public void insertString(int offs, String str, AttributeSet attribute) throws BadLocationException {
    Element root = this.getDefaultRootElement();
    int lineCount = getLineCount(str);
    if (lineCount + root.getElementCount() <= maxLines){
        super.insertString(offs, str, attribute);
    else {
        Toolkit.getDefaultToolkit().beep();
* get Line Count
* @param str
* @return the count of '\n' in the String
private int getLineCount(String str){
     String tempStr = new String(str);
     int index;
     int lineCount = 0;
     while (tempStr.length() > 0){
          index = tempStr.indexOf("\n");
          if(index != -1){
               lineCount++;
               tempStr = tempStr.substring(index+1);
          else{
               break;
     return lineCount;
}Thats work just fine but still not enough
I tried to set also maxCharsInLine to count the chars in similar way but it is to complicated and there is a lot of problems with it
Thank you, but still waiting for an answer