FFmpegConvert/src/main/java/net/knarcraft/ffmpegconverter/utility/StringUtil.java

package net.knarcraft.ffmpegconverter.utility;

/**
 * A class which helps with operations on strings
 */
final class StringUtil {

    private StringUtil() {
    }

    /**
     * Finds all substrings between two substrings in a string
     *
     * @param string <p>The string containing the substrings.</p>
     * @param start  <p>The substring before the wanted substring.</p>
     * @param end    <p>The substring after the wanted substring.</p>
     * @return <p>A list of all occurrences of the substring.</p>
     */
    static String[] stringBetween(String string, String start, String end) {
        int startPosition = string.indexOf(start) + start.length();
        //Return if the string is not found
        if (!string.contains(start) || string.indexOf(end, startPosition) < startPosition) {
            return new String[]{};
        }
        int endPosition = string.indexOf(end, startPosition);
        //Get the string between the start and end string
        String outString = string.substring(startPosition, endPosition).trim();
        String nextString = string.substring(endPosition + end.length());
        //Add other occurrences recursively
        return ListUtil.concatenate(new String[]{outString}, stringBetween(nextString, start, end));
    }
}