Question

就像标题所说的那样，我可以把它写在我想要的文件的第一件事上，但之后它就不再写了。我通过调试器运行它，看到它甚至没有读下一行（我知道这是因为它没有填充数组。）我试着手动推进指针（我不是在循环结束时用＆＃34; line = in.readline;＆＃34;来知道这是否真的是你能做的事情，但它只是抛出一个＆＃34; nosuchelement＆＃34;例外。这是我的尝试块＆＃34;

try
  {
     in = new BufferedReader(new FileReader("lab7input.txt"));

     outNormal = new PrintWriter(new File("normal.txt"));
     outVegetarian = new PrintWriter(new File("vegetarian.txt"));
     outPescetarian = new PrintWriter(new File("pescetarian.txt"));
     outInvalid = new PrintWriter(new File("invalid.txt"));

     String line = in.readLine();
     StringTokenizer st = new StringTokenizer(line);

     while (line != null)
     {
        Scanner sc = new Scanner(line);
        while(sc.hasNext())
        {
            if(st.countTokens() == 3)
            {
                attendee3[0] = sc.next();
                attendee3[1] = sc.next();
                attendee3[2] = sc.next();

                if(Integer.parseInt(attendee3[2]) == 0)
                {
                    outNormal.println(attendee3[0] + " " + attendee3[1]);
                    outNormal.close();
                }
                else if(Integer.parseInt(attendee3[2]) == 1)
                {
                    outVegetarian.println(attendee3[0] + " " + attendee3[1]);
                    outVegetarian.close();
                }
                else if(Integer.parseInt(attendee3[2]) == 2)
                {
                    outPescetarian.println(attendee3[0] + " " + attendee3[1]);
                    outPescetarian.close();
                }
                else
                {
                    outInvalid.println(attendee3[0] + " " + attendee3[1]);
                    outInvalid.close();
                }
            }  
            if(st.countTokens() == 4)
            {
                attendee4[0] = sc.next();
                attendee4[1] = sc.next();
                attendee4[2] = sc.next();

                if(Integer.parseInt(attendee4[3]) == 0)
                {
                    outNormal.println(attendee4[0] + " " + attendee4[1] + " " + attendee4[2]);
                    outNormal.close();
                }
                else if(Integer.parseInt(attendee4[3]) == 1)
                {
                    outVegetarian.println(attendee4[0] + " " + attendee4[1] + " " + attendee4[2]);
                    outVegetarian.close();
                }
                else if(Integer.parseInt(attendee4[3]) == 2)
                {
                    outPescetarian.println(attendee4[0] + " " + attendee4[1] + " " + attendee4[2]);
                    outPescetarian.close();
                }
                else
                {
                    outInvalid.println(attendee4[0] + " " + attendee4[1] + " " + attendee4[2]);
                    outInvalid.close();
                }
            }
            //line = in.readLine();
        }
     }
  }

Answer 1

更简单，更清洁的方式

 String line = in.readLine();

 while (line != null)
 {
    String arr [] = line.split ();
    if(arr.length == 3)
    {
            attendee3[0] = arr[0];
            attendee3[1] = arr[1];
            attendee3[2] = arr[2];
    }
   // other count code

   line = in.readLine();
 }

Answer 2

您必须将line = in.readLine()放在下面的一个区块中，而不是放在扫描仪的一个区块中。

Answer 3

不仅如此，我还拥有Scanner只能读取UTF-8编码.txt文件的体验。所以要始终确保它们是UTF-8编码如果它们不仅仅是打开文件并使用该编码保存它。

扫描仪无法从文件中读取下一行。 JAVA

3 个答案: