Skip to main content

Java - Difference between StringUtils.EMPTY and StringUtils.isEmpty()






StringUtils.EMPTY vs StringUtils.isEmpty()

StringUtils.EMPTY is a final static member of StringUtil class that equates to "" i.e empty String.

whereas 

StringUtils.isEmpty() Checks if a String is empty ("") or null.


How does StringUtils.EMPTY.equals(string) different from StringUtils.isEmpty(string)  


public class ParentTest {

         public static void main(String[] args){
               String str = "";
               String str2 = null;
    
               if(StringUtils.EMPTY.equals(str)){
                    System.out.println("str1.1 is empty");
               }
    
               if(StringUtils.isEmpty(str)){
                    System.out.println("str1.2 is empty");
               }
   
               if(StringUtils.EMPTY.equals(str2)){
                    System.out.println("str2.1 is empty");
               }
    
               if(StringUtils.isEmpty(str2)){
                    System.out.println("str2.2 is empty");
               }
         }
}

results in 

str1.1 is empty

str1.2 is empty

str2.2 is empty


Though StringUtils.isEmpty(str2) is saying that its checking for empty str2 but its actually checking both null as well as blank string for str2.

Comments

Post a Comment

Popular posts from this blog

Mockito interview Questions

1.       Question 1. What Is Mockito? Answer : Mockito allows creation of mock object for the purpose of Test Driven Development and Behavior Driven development. Unlike creating actual object, Mockito allows creation of fake object (external dependencies) which allows it to give consistent results to a given invocation. 2.       Question 2. Why Do We Need Mockito? What Are The Advantages? Answer : Mockito differentiates itself from the other testing framework by removing the expectation beforehand. So, by doing this, it reduces the coupling. Most of the testing framework works on the "expect-run-verify". Mockito allows it to make it "run-verify" framework. Mockito also provides annotation which allows to reduce the boilerplate code. 3.       Question 3. Can You Explain A Mockito Framework? Answer : In Mockito, you always check a particular class. The dependency in that class is injected using m...
2 comments
Read more

JAVA Expert Interview Questions Answers 2017

Java Basics ::  Interview Questions and Answers Home  »  Interview Questions  »  Technical Interview  »  Java Basics  » Interview Questions 1.     What is the difference between a constructor and a method? A constructor is a member function of a class that is used to create objects of that class. It has the same name as the class itself, has no return type, and is invoked using the new operator. A method is an ordinary member function of a class. It has its own name, a return type (which may be void), and is invoked using the dot operator. 2.     What is the purpose of garbage collection in Java, and when is it used? The purpose of garbage collection is to identify and discard objects that are no longer needed by a program so that their resources can be reclaimed and reused. A Java object is subject to garbage collection when it becomes unreachable to the program in which it is used. 3.  ...
3 comments
Read more

Java Example Program to Convert List to Set

import java.util.ArrayList; import java.util.HashSet; import java.util.Set; public class ListToSet {  /**   * @author Amarjit Kumar   * @category interview questions   *   * Description: Convert List to set in java with example program   *   */  public static void main(String[] args) {   ArrayList<String> arrList= new ArrayList<>();   arrList.add("Java");   arrList.add("Java");   arrList.add("List to String");   arrList.add("Example Program");   Set<String> strSet = new HashSet<String>(arrList);   System.out.println(strSet);   System.out.println(arrList);  } } /*  * Java program to convert list to set. Convert ArrayList of string to HashSet  * in java example program How to convert List to Set in java Set<String> strSet  * = new HashSet<String>(arrList); HashSet having a constructor which will take  * list as an ar...
Post a Comment
Read more