[Mouldy_Underwear]

I get this error message "Exception in thread "main" java.lang.StringIndexOutOfBounds Exception: String index out of range: 0
at java.lang.String.charAt(Unknown Source)
at AQAConsole.readChar(AQAConsole.j ava:37)
at AQAConsole.readChar(AQAConsole.j ava:29)
at COMP1_Summer_2012_SkelProg_Java. getMove(COMP1_Summer_2012_SkelPr og_Java.java:248)
at COMP1_Summer_2012_SkelProg_Java. playGame(COMP1_Summer_2012_SkelP rog_Java.java:367)
at COMP1_Summer_2012_SkelProg_Java. <init>(COMP1_Summer_2012_SkelPro g_Java.java:422)
at COMP1_Summer_2012_SkelProg_Java. main(COMP1_Summer_2012_SkelProg_ Java.java:444)"

My teacher says that it may be related to the coding in one of these sections:

char getMove() {
boolean charEntered = false;
char move;
move = console.readChar();
charEntered = Character.isLetter(move);
if (!charEntered){
move='x';
}
else
{
move = Character.toUpperCase(move);
}
move = Character.toUpperCase(move);
console.println();
return move;


boolean checkValidMove(CellReference playerPosition, char direction) {
boolean validMove;
validMove = true;
if (!(direction == 'N' || direction == 'S' || direction == 'W'
|| direction == 'E' || direction == 'M')) {
validMove = false;
}
return validMove;
}



void playGame(char[][] cavern, CellReference[] trapPositions, CellReference monsterPosition, CellReference playerPosition, CellReference flaskPosition, Logical monsterAwake) {
int count;
boolean eaten;
boolean flaskFound;
char moveDirection;
boolean validMove;
eaten = false;
flaskFound = false;
displayCavern(cavern, monsterAwake);
do {
do {
displayMoveOptions();
moveDirection = getMove();
validMove = checkValidMove(playerPosition, moveDirection);
} while (!validMove);
if (moveDirection != 'M') {
makeMove(cavern, moveDirection, playerPosition);
displayCavern(cavern, monsterAwake);
flaskFound = checkIfSameCell(playerPosition, flaskPosition);
if (flaskFound) {
displayWonGameMessage();
}


We have tried fixing it, the teacher says that the character isn't being read when we press enter, the problem occurs when we don't enter a letter into the program and simply press enter, how do I fix this?!?!?

[roblee]

It's a bug in the provided AQAConsole class. Obviously they're using something similar to

String line = scanner.readLine();
return line.charAt(0);

When they should be using

do {
  String line = scanner.readLine();
} while (line.length() < 1);
return line.charAt(0);

Or even better:

do {
  int c = System.in.read();
 if (c == -1) throw new EOFException();
} while (!Character.isLetter( (char) c));

return (char) c;