Java basics: A simple string tool class

Empty string: either null or empty string ("");

Write a method to judge whether the string is not empty:
Haslength (string S );

Write a method to judge whether the string is null:
Isblank (string S );

/*** String tool class **/public class stringutil {/*** determines whether the string is not empty * @ Param STR string to be judged * @ return returns true if it is not empty, if it is null, false */public static Boolean haslength (string Str) {return Str! is returned! = NULL &&! "". Equals (STR);}/*** determines whether a string is null * @ Param STR the string to be judged * @ return returns true if it is null, if not empty, false */public static Boolean isblank (string Str) {return! is returned! Haslength (STR );}}