Utility class for validating strings.

TODO(mmendez): Is there a better place for this?

class StringValidator {
 /**
  * Returns true if the string is empty or null.
  * 
  * @param string to test if null or empty
  * 
  * @return true if the string is empty or null
  */
 static bool isEmptyOrNullString(String string) {
   return (string == null) || (0 == string.trim().length);
 }

 /**
  * Throws if <code>value</code> is <code>null</code> or empty. This method
  * ignores leading and trailing whitespace.
  * 
  * @param name the name of the value, used in error messages
  * @param value the string value that needs to be validated
  * 
  * @throws IllegalArgumentException if the string is empty, or all whitespace
  * @throws NullPointerException if the string is <code>null</code>
  */
 static void throwIfEmptyOrNull(String name, String value) {
   assert (name != null);
   assert (name.trim().length != 0);

   throwIfNull(name, value);

   if (0 == value.trim().length) {
     throw new Exception("$name cannot be empty");
   }
 }

 /**
  * Throws a {@link NullPointerException} if the value is <code>null</code>.
  * 
  * @param name the name of the value, used in error messages
  * @param value the value that needs to be validated
  * 
  * @throws NullPointerException if the value is <code>null</code>
  */
 static void throwIfNull(String name, Object value) {
   if (null == value) {
     throw new Exception("$name cannot be null");
   }
 }
}