Java tutorial
//package com.java2s; //License from project: Apache License public class Main { public static String fullWidthToHalfWidth(String s) { if (isEmpty(s)) { return s; } char[] source = s.toCharArray(); for (int i = 0; i < source.length; i++) { if (source[i] == 12288) { source[i] = ' '; // } else if (source[i] == 12290) { // source[i] = '.'; } else if (source[i] >= 65281 && source[i] <= 65374) { source[i] = (char) (source[i] - 65248); } else { source[i] = source[i]; } } return new String(source); } public static boolean isEmpty(final CharSequence cs) { return cs == null || cs.length() == 0; } }