问当我尝试使用Eclipse用Java读取文件时，它总是说找不到它？

EN

import java.util.*;
import java.io.*;

public class prob1 {
    public static void main(String[] args)
    {

        try
        {
            FileReader in = new FileReader("practice.in");
            Scanner scanner = new Scanner(in);

            while(scanner.hasNext())
            {
                int number = scanner.nextInt();
                if(number==0)break;
                int sum = 0;

                for (int i=0; i<number; i++)
                {
                    int x = scanner.nextInt();
                    sum += x;                
                }
                System.out.println("Sum = "+sum);
            }
        }
        catch(Exception e)
        {
            e.printStackTrace();
        }


    }
}