Can someone help me with this code challenge?

while(who.equalsIgnoreCase("banana"))

String who;

do{
//Here is the prompting code
console.printf("Knock Knock.\n");
who = console.readLine("Who's there?  ");
console.printf("%s who?\n", who);
} while(who.equalsIgnoreCase("banana"));

/*  So the age old knock knock joke goes like this:
        Person A:  Knock Knock.
        Person B:  Who's there?
        Person A:  Banana
        Person B:  Banana who?
        ...This repeats until Person A answers Orange
        Person A:  Orange
        Person B:  Orange who?
        Person A:  Orange you glad I didn't say Banana again?
*/

//Here is the prompting code
console.printf("Knock Knock.\n");
String who = console.readLine("Who's there?  ");
console.printf("%s who?\n", who);
    boolean isInvalidWord;

      do 
        {

    who = console.readLine("Who is it? ");
    isInvalidWord = (who.equalsIgnoreCase("banana") 

      if (isInvalidWord)
      {
        console.printf("Try to input banana \n\n");
      }

     }

      while (isInvalidWord);