运行时错误 - 程序终止

Question

我的程序由于某种原因终止.它是一个岩石纸 - scisors模拟.当我在第一个nextLine中输入内容时终止.如果有人可以请求帮助.

import java.util.*;
import java.math.*;

public class RockPapperScissors {

 /**
  * @param args
  */

 public static void main(String[] args) {
  Scanner in=new Scanner(System.in);
  String comp, user;
  comp=getComp();
  System.out.println("Enter rock, paper, or scissors");
  user=in.nextLine();
  winner(comp, user);


 }

 public static String getComp(){
  Random rand=new Random();
  String answer;
  int ran=rand.nextInt(3);
  if(ran==1)
   answer="rock";
  else if(ran==2)
   answer="paper";
  else 
   answer="scissors";
  return answer;}
 public static void winner(String com, String use){

  if(com=="rock" && use=="rock")
   System.out.println("Its a tie");
   else if(com=="rock" && use=="paper") 
    System.out.println("You win!");
   else if(com=="rock" && use=="scissors")
    System.out.println("Computer wins, you FAIL");
  else if(com=="paper" && use=="rock")
    System.out.println("Computer wins, you FAIL");
   else if(com=="paper" && use=="paper")
    System.out.println("Its a tie");
   else if(com=="paper" && use=="Scissors")
    System.out.println("You win!");
  else if(com=="scissors" && use=="rock")
    System.out.println("You win");
   else if(com=="scissors" && use=="paper")
    System.out.println("Computer wins, you FAIL");
   else if(com=="scissors" && use=="scissors")
    System.out.println("Its a tie");}


 }

Answer 1

对于字符串比较,请使用.equals()而不是==.