Answers for "difference between isblank and isempty"

isblank vs isempty

StringUtils.isEmpty(null)      = true
 StringUtils.isEmpty("")        = true  
 StringUtils.isEmpty(" ")       = false  
 StringUtils.isEmpty("bob")     = false  
 StringUtils.isEmpty("  bob  ") = false

isblank vs isempty

public class Main 
{
    public static void main(String[] args) 
    {
        System.out.println( "ABC".isBlank() );      //false
        System.out.println( "  ".isBlank() );       //true
 
        System.out.println( "ABC".isEmpty() );      //false
        System.out.println( "  ".isEmpty() );       //false
    }
}

isblank vs isempty

StringUtils.isBlank(null)      = true
 StringUtils.isBlank("")        = true  
 StringUtils.isBlank(" ")       = true  
 StringUtils.isBlank("bob")     = false  
 StringUtils.isBlank("  bob  ") = false