Write code to swap Case
import java.util.ArrayList; import java.util.List; public class Main{ public static void main(String[] argv){ String str = "book2s.com"; System.out.println(swapCase(str)); }/*from ww w .j av a 2 s. c o m*/ public static String swapCase(String str) { if (isEmpty(str)) { return str; } char[] buffer = str.toCharArray(); boolean whitespace = true; for (int i = 0; i < buffer.length; i++) { char ch = buffer[i]; if (Character.isUpperCase(ch)) { buffer[i] = Character.toLowerCase(ch); whitespace = false; } else if (Character.isTitleCase(ch)) { buffer[i] = Character.toLowerCase(ch); whitespace = false; } else if (Character.isLowerCase(ch)) { if (whitespace) { buffer[i] = Character.toTitleCase(ch); whitespace = false; } else { buffer[i] = Character.toUpperCase(ch); } } else { whitespace = Character.isWhitespace(ch); } } return new String(buffer); } public static boolean isEmpty(String chkStr) { if (chkStr == null) { return true; } else { return "".equals(chkStr.trim()) ? true : false; } } }