5 Ways To Banking Concern Jibe If String Is Empty Inwards Coffee - Examples

String inwards Java is considered empty if its non aught too it’s length is zero. By the way earlier checking length you lot should verify that String is non aught because calling length() method on null String will effect inwards java.lang.NullPointerException. Empty String is represented past times String literal “”. definition of empty String may last extended to those String every bit good which entirely contains white infinite but its an specific requirement too inwards full general String amongst white infinite are non considered every bit empty String inwards Java. Since String is ane of the well-nigh oft used shape too normally used inwards method arguments, nosotros often needs to cheque if String is empty or not. Thankfully at that topographic point are multiple ways to notice if String is empty inwards Java or not. You tin strength out every bit good count divulge of characters inwards String, every bit String is represented every bit graphic symbol array and determine if String is empty or not. If count of characters is null than its an empty String. In this Java String tutorial nosotros going to meet 5 ways to notice if whatever String inwards Java is empty or not. Here are our 5 ways to cheque empty String :

1) Checking if String is empty past times using String.length()

2) Find  if String is empty past times using equals() method of String

3) Checking if String is empty past times using isEmpty() method String, entirely available from Java half dozen onwards.

4) Find if String is empty using Apache park StringUtils class

5) Using Spring framework’s StringUtils.hasLength() method.

Find if String is empty past times checking length

It's the well-nigh slowly too pop method to verify if String is empty or not. You tin strength out notice length of String past times calling

length() method which genuinely returns divulge of characters inwards String. Be careful to cheque if String is aught earlier calling length()to avoid NullPointerException. here is an event to check is String empty using length:

if(string != null && string.length() == 0){ return true; }

String empty using equals method

You can every bit good compare String to empty String literal "" to cheque if it’s empty or not. equals method inwards Java returns faux if other declaration is null, too thus it automatically checks for null string every bit well. Here is code event of checking emptiness of String using equals:

public static boolean isStringEmptyByEquals(String input){
        return "".equals(input);
}

Use isEmpty() method of Java 6

You tin strength out every bit good cheque if String is empty or non past times using isEmpty() method of String class added inwards Java6. This is past times far well-nigh readable way but you withdraw to cheque if String is null or non earlier calling isEmpty() method. meet code event department for purpose of isEmpty() method.

String Empty cheque using Apache Commons lang StringUtils

Apache park lang has a StringUtils shape which has static utility method isEmpty(String input), which returns truthful if input string is null or has length greater than zero. Note this is dissimilar than our get-go method because it see aught every bit empty String spell nosotros are hither only considering null length String every bit empty String.  If you lot are already using Apache park lang inwards your projection e.g. for overriding toString method, than you lot tin strength out purpose StringUtils instead of writing your ain method. Check event department to meet how to purpose StringUtils.isEmpty(), past times the way hither is output of StringUtils for only about mutual input :

StringUtils.isEmpty("")        = true

StringUtils.isEmpty(null)      = true

StringUtils.isEmpty(" ")       = false

StringUtils.isEmpty("fix")     = false

StringUtils.isEmpty("  fix  ") = false

Check if String is Empty inwards Java - Using Spring

Spring is pop Java framework too well-nigh of novel projects uses Spring to accept benefit of dependency Injection, it render StringUtils shape for performing mutual String operation. StringUtils provides method called hasLength(input String), which returns truthful if String is non aught too contains whatever character, including white space. You tin strength out every bit good purpose hasLength to determine if String is empty inwards Java or not. Next department has code examples of all 5 methods of checking empty string mentioned inwards this Java tutorial, past times the way hither is how hasLength() treats aught too empty String :

StringUtils.hasLength("") = false

StringUtils.hasLength(null) = false

StringUtils.hasLength(" ") = true

StringUtils.hasLength("Hello") = true

Code Example to verify if String is empty inwards Java

Here is consummate code event of How to cheque if String is empty inwards Java. This programme combines all approaches nosotros own got discussed too thus fart to cheque if Java String is empty or not. One interesting affair to banknote inwards this programme is How I own got used StringUtils from Spring Framework. Since at that topographic point are 2 classes amongst same hollo but from dissimilar package, i.e. StringUtils from Apache too Spring. You tin strength out entirely import ane too you lot withdraw to purpose other amongst its fully qualified hollo to avoid ambiguity.

import org.apache.commons.lang.StringUtils;

public class StringEmptyTest {

    public static void main(String args[]) {
 
        String input1 = "";
        String input2 = null;
        String input3 ="abc";
     
        //determine if String is empty using length method , every bit good checks if string is null
        System.out.println("checking if String empty using length");
        System.out.println("String " + input1 + " is empty :" +isStringEmpty(input1) );
        System.out.println("String " + input2 + " is empty :" +isStringEmpty(input2) );
        System.out.println("String " + input3 + " is empty :" +isStringEmpty(input3) );
     
        //determine if String is empty using equals method
        System.out.println("find if String empty using equals");
        System.out.println("String " + input2 + " is empty :" +isStringEmptyByEquals(input2) );
     
         //determine if String is empty using isEmpty of Java 6
        System.out.println("find if String empty using isEmpty method of Java 6");
        System.out.println("String " + input3 + " is empty :" + input3.isEmpty());
     
        //determine if String is empty past times Apache park StringUtils
        System.out.println("check if String empty past times park StringUtils");
        System.out.println("String " + input2 + " is empty :" + StringUtils.isEmpty(input2));
     
        //determine if String is empty past times Spring framework StringUtils hasLength method
        System.out.println("check if String empty past times Spring framework StringUtils");
        System.out.println("String " + input2 + " is empty :" + org.springframework.util.StringUtils.hasLength(input2));

     
    }
 
    public static boolean isStringEmpty(String input){
        if(input != null && input.length() == 0){
            return true;
        }
        return false;
    }
 
    public static boolean isStringEmptyByEquals(String input){
        return "".equals(input);
    }
}

Output:
checking if String empty using length
String  is empty :true
String null is empty :false
String abc is empty :false

notice if String empty using equals
String null is empty :false

notice if String empty using isEmpty method of Java 6
String abc is empty :false

cheque if String empty past times park StringUtils
String null is empty :true

cheque if String empty past times Spring framework StringUtils
String null is empty :false

That’s all on How to cheque if String is empty inwards Java. I affair Java half dozen isEmpty() method is to a greater extent than readable than whatever other alternative but it’s non aught prophylactic which way either write your ain method or purpose hasLength() from Spring Framework.  By the way last careful amongst aught String every bit only about programmer see aught string every bit empty String too fifty-fifty Apache park StringUtils.isEmpty() method render truthful for aught String.

Further Learning
Spring Framework 5: Beginner to Guru
Why graphic symbol array is improve than String for storing password inwards Java

How to supplant characters on String inwards Java

How to split upwards String inwards Java amongst example

How to convert String to appointment inwards Java

How to convert String to Integer inwards Java

10 advanced String Interview Questions inwards Java