【小白Java问题】为什么这个while循环达到条件了却终止不了？

Question

package CityDistance;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Scanner;


public class CityDistance {
    private ArrayList<String> city = new ArrayList<String>();
    private int answer = 0;
    HashMap<String, Integer> distance = new HashMap<String, Integer>();

    public void input()
    {
        Scanner in = new Scanner(System.in);
        String temp = null;
        while ((temp = in.next()) != "###")
        {
            city.add(temp);
        }

        int number = city.size();   
        for ( int i = 0; i < number; i++ )
        {
            for ( int j = 0; j < number; j++ )
            {
                String key = "" + city.get(i) + city.get(j);
                distance.put(key, in.nextInt());
            }
        }
        in.close();
    }   

    public int FindDistance(String A, String B)
    {
        String str = A + B;
        answer = distance.get(str);
        System.out.println(answer);
        return answer;
    }

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        CityDistance cd = new CityDistance();   
        cd.input();
        cd.FindDistance(in.next(), in.next());
        in.close();
    }
}

输入如下：
aaa bbb ccc ###
0 1 2
1 0 3
2 3 0
aaa bbb

input 函数里的第一个 while ，已经设定好了遇到 "###" 的输入就停止往 city 里加东西，但调试时发现 while 并没有停止，反而把后面的0、1、2都添到 city 里去了……

跪求大神解答！

Answer 1

 import java.util.*;

public class CityDistance {

    private List<String> city = new ArrayList<String>();
    private int answer = 0;
    private Map<String, Integer> distance = new HashMap<String, Integer>();

    public void input()
    {
        Scanner in = new Scanner(System.in);
        String temp = null;
        System.out.println("请输入城市（“###”结束输入）：");
        /*
        *   注意：字符串是一个对象，不是基本类型，不能使用==比较，要使用equals
        */
        while (!(temp = in.next()).equals("###"))
        {
            city.add(temp);
        }

        int number = city.size();   
        for ( int i = 0; i < number; i++ )
        {
            for ( int j = 0; j < number; j++ )
            {
                String key = "" + city.get(i) + city.get(j);
                System.out.print("请输入"+city.get(i) + "<-->"+city.get(j)+"的距离：");
                distance.put(key, in.nextInt());
            }
        }
        /*
        *   注意：不能关闭，否则的话之后即使在main函数里有一个scanner，也不能使用
        */
        //in.close();
    }   

    public int FindDistance(String A, String B)
    {
        String str = A + B;
        if(distance.containsKey(str)){
            answer = distance.get(str);
            return answer;
        }
        return 0;
    }

    public static void main(String[] args) {
        CityDistance cd = new CityDistance();   
        cd.input();
        Scanner in = new Scanner(System.in);
        System.out.println("查询城市间距离：");
        System.out.print("输入城市1：");
        /*
        *   注意：input()里不要调用in.close(),否则这里得不到输入，你可以测试一下，加深下印象
        */
        String A = in.next();
        System.out.print("输入城市2：");
        String B = in.next();
        System.out.println(A + "<-->"+B + "的距离：" + cd.FindDistance(A,B));
    }
}