Java tutorial
/* Keep B and o = BoB Squeeze B and o = Borisbbbecker */ import org.apache.commons.lang.CharSetUtils; public class CharSetUtilsTrial { public static void main(String[] args) { // Keeps only the characters specified System.out.println("Keep B and o = " + CharSetUtils.keep("BorisBecker", "Bo")); // BoB // Removes specified character repetitions System.out.println("Squeeze B and o = " + CharSetUtils.squeeze("BBoooorisbbbecker", "Bo")); // Borisbbbecker } }