Java tutorial
//package com.java2s; public class Main { public static boolean isDateYM(String str) { if (isEmpty(str)) return false; // return str.matches("^\\d{4}[0-1][0-9]$"); return str.matches("^\\d{4}(0[1-9]|1[0-2])$"); } public static boolean isEmpty(String str) { if (str == null) return true; str = str.trim(); if (str.length() == 0) return true; return false; } }