InputMismatchException 왜생기는걸까

[뭥미(114.207)]

public boolean add(Star aStar)

{

if(this.isFull())

return false;

else

if(!doesContain(aStar)){

this._elements[this._size] = aStar;

this._size++;

return true;}

else{

return false;

}

}

private void input() {

// 입력 처리 함수

this.showMessage(MessageID.Notice_InputStar);

this.showMessage(MessageID.Notice_InputStarXCoordinate);

int xCoordinate = this._appView.inputInt();

this.showMessage(MessageID.Notice_InputStarYCoordinate);

int yCoordinate = this._appView.inputInt();

this.showMessage(MessageID.Notice_InputStarName);

String starName = this._appView.inputString();

if (!this._starCollector.add(new Star(xCoordinate,yCoordinate,starName)))

this.showMessage(MessageID.Error_Input);

}

자료구조 set이고 add호출해서 input에 입력시키는건데

왜 InputMismatchException가 생기지?