import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
 public class Test {
 
     private static boolean matches(String pattern, String input){
 	if(input == null) return false;
 	
 	Pattern p = Pattern.compile(pattern);
 	Matcher m = p.matcher(input);
 	
 	return m.matches();
     }
     
     public static void main(String[] args) {
 	String pattern = "[a-z]{1}";
 	
 	String input0 = null;
 	String input1 = "";
 	String input2 = "a";
 	String input3 = "ab";
 	
 	System.out.println("used pattern: <" + pattern + ">");
 	System.out.println("<" + input0 + "> => " + Test.matches(pattern, input0));
 	System.out.println("<" + input1 + "> => " + Test.matches(pattern, input1));
 	System.out.println("<" + input2 + "> => " + Test.matches(pattern, input2));
 	System.out.println("<" + input3 + "> => " + Test.matches(pattern, input3));
     }
 
 }