To validate and limit the number of lines in a text using regular expressions in Java, you can use the following regular expression pattern:

String textPattern = "^([^\n]*\n){1,3}[^\n]*$";

This regular expression pattern matches texts with up to three lines. The pattern first matches zero or more non-newline characters, followed by a newline character, up to three times. Then it matches any remaining non-newline characters, ensuring that the text ends with a newline or the end of the string.

To use this regular expression to validate a text and limit the number of lines, you can use the following code:

String text = "This is the first line.\nThis is the second line.\nThis is the third line.\nThis is the fourth line.";
if (text.matches(textPattern)) {
    System.out.println("Valid text: " + text);
} else {
    System.out.println("Invalid text: " + text);
}

In the example above, the "text" string is checked if it matches the "textPattern" regular expression. If it does, it is considered a valid text with up to three lines.

Note that while this regular expression pattern is a good starting point for limiting the number of lines in a text, it may not work for all cases. For example, it does not account for the possibility of empty lines or lines with only whitespace characters. It's always a good idea to test your regular expression pattern against various inputs and to use additional validation methods (such as counting the number of newline characters in the input) to ensure the input is valid.