The promptForDragon() method is not working. When the user inters an empty line, this should get printed to the screen " Error - dragon prompt cannot be empty." but for what ever reqson, the program is not doing that

here is the code

/**

* YOUR DESCRIPTION OF THIS PROGRAM HERE

* @author YOUR NAME HERE

* @version DATE HERE

*/

import java.util.Random;

import java.util.Scanner;

public class DragonTrainers {

private static final String[] DRAGONS = { "Plant", "Water", "Fire" };

public static int getNumberOfMatches(Scanner keyboard) {

System.out.print("How many matches will we play?");

int matches=0;

int cc =0;

matches=keyboard.nextInt();

while (cc!= -1){

if(matches>0){

cc = -1;

break;

}

else{

System.out.println(" ERROR - number of matches must be positive!");

System.out.print("How many matches will we play?");

matches=keyboard.nextInt();

keyboard.nextLine();

}

}

return matches;

}

public static String promptForDragon(Scanner keyboard) {

System.out.print("Please select a dragon [Plant/Water/Fire]: ");

String s="";

while(true){

s=input.nextLine();

if(!s.equals("")){

break;

}

else{

System.out.print("ERROR - Dragon prompt cannot be empty.");

}

}

return s;

}

public static int dragonToNumber(char dragon) {

if(dragon=='P'){

return 0;

}else if(dragon=='W'){

return 1;

}else if(dragon=='F'){

return 2;

}

return -1;

}

public static int determineWinner(int player, int cpu) {

if(player==cpu){

return 0;

}else if(player==0){

if(cpu==1){

return 1;

}else{

return -1;

}

}else if(player==1){

if(cpu==2){

return 1;

}else{

return -1;

}

}else if(player==2){

if(cpu==0){

return 1;

}else{

return -1;

}

}

return -1;

}

public static void displayMatchResult(int player, int cpu, int winner) {

if(winner==1){

System.out.println(DRAGONS[player]+" defeats "+DRAGONS[cpu]+" - you win!");

}

else if(winner==-1){

System.out.println(DRAGONS[cpu]+" defeats "+DRAGONS[player]+" - you lose!");

}

else{

System.out.println("A Tie!");

}

}

public static void displayFinalResult(int wins, int losses, int ties) {

System.out.println("The tournament is over!");

System.out.println("We tied "+ties+" matches.");

System.out.println("I won "+losses+" matches.");

System.out.println("You won "+wins+" matches.");

if(losses>wins){

System.out.println("I am the winner!");

}

else if(losses

System.out.println("You are the winner!");

}

else{

System.out.println("Neither of us can claim victory here!");

}

}

public static void main(String[] args) {

// Prompt for a random number seed

Scanner keyboard = new Scanner(System.in);

System.out.print("Enter a random seed: ");

int seed = Integer.parseInt(keyboard.nextLine());

// Create a Random instance with the seed

Random rnd = new Random(seed);

// Prompt for number of matches to play

int totalMatches = getNumberOfMatches(keyboard);

// Start with wins, losses and ties at 0.

// Repeat until all matches have been played (use the sum of the

// results so we don't need another variable)

int wins = 0, losses = 0, ties = 0;

while ((wins + losses + ties) < totalMatches) {

// Ask the user for a dragon to use

String input = promptForDragon(keyboard);

// Get the first character of the user's input as an uppercase

// value.

char dChar = input.toUpperCase().charAt(0);