Java pads numbers in strings with zeros using regular rules

Sometimes you encounter this situation when sorting strings:

Water Margin Episode 1.mp4

Water Margin Episode 2.mp4

…

Water Margin Episode 10.mp4

Water Margin Episode 11.mp4

When sorting, "Water Margin Episode 10.mp4" will be ranked before "Water Margin Episode 2.mp4", and the sorted result becomes:

Water Margin Episode 1.mp4

Water Margin Episode 10.mp4

Water Margin Episode 11.mp4

Water Margin Episode 2.mp4

…

solution

You can first add 0 to the numbers in the string through regular expression, and then remove the excess 0 through regular expression.

String text = "水浒传 第11集.mp4";
text = text.replaceAll("(\\d+)", "00$1");
text = text.replaceAll("0*([0-9]{3})", "$1");
System.out.println(text);

Processed result:

Water Margin Episode 011.mp4