Question

我正在尝试从文件中读取数据并加载到二维数组中，然后将其打印到屏幕上，但输出错误：

输出：

Analysis report of the temperatre reading for the past 10 days 
The code throws an exception
The code throws an exception
The code throws an exception
The code throws an exception
The code throws an exception
The code throws an exception
The code throws an exception
The code throws an exception
The code throws an exception

我创建了一个名为temperature.txt的数据文件。数据文件包含高和低。过去10天的低温格式（低）| （高）：

+-------------+-------+-------+-------+-------+-------+-------+-------+-------+-------+-------+
| Day         | 1     |  2    |  3    |   4   |   5   |   6   |   7   |   8   |   9   |  10   |
+-------------+-------+-------+-------+-------+-------+-------+-------+-------+-------+-------+
| Temperature | 30|32 | 29|30 | 25|28 | 25|29 | 27|31 | 28|32 | 26|30 | 24|32 | 24|41 | 27|32 |
+-------------+-------+-------+-------+-------+-------+-------+-------+-------+-------+-------+

以下是我的代码：

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

public class Temperature {


    public static void main(String[] args) {

        StringTokenizer tokenizer;
        String line;
        String file="temperature.txt";
        int[][] temp=new int[10][2];
        int sumHigh, sumLow;
        FileReader fr=null;
        BufferedReader br=null;

        try
        {
            fr=new FileReader(file);
            br=new BufferedReader(fr);

            line=br.readLine();
            System.out.println("Analysis report of the temperature reading for the past 10 days " + line);


            for(int row=0; row<temp.length; row++)
            {
               tokenizer=new StringTokenizer(line, "|");

               if(row != 0)
               {
                   try
                   {

                       if(row % 2 == 0)
                       {
                           sumHigh = Integer.parseInt(tokenizer.nextToken());
                           temp[row][1]=Integer.parseInt(tokenizer.nextToken());

                       }
                       else if (row % 2 != 0) 
                       {

                           sumLow = Integer.parseInt(tokenizer.nextToken());
                           temp[row][0]=Integer.parseInt(tokenizer.nextToken());

                       }
                   }
                   catch(Exception e)
                   {
                       System.out.println("The code throws an exception");
                   }
               }

            }

            br.close();

        }

        catch(FileNotFoundException e)
        {
            System.out.println("The file " + file + " was not found");
        }
        catch(IOException e)
        {
            System.out.println("Reading error");
        }
        catch(NumberFormatException e)
        {
            System.out.println("Parsing error");
        }
        finally
        {
            if(fr != null)
            {
                try
                {
                    fr.close();
                }
                catch(IOException e)
                {
                    System.out.println("Reading error");
                }
            }
        }


    }

}

Answer 1

我会将解析温度的逻辑移到一个单独的函数中。像这样：

public class Temperature {
    public static class MinMax {
        private int min;
        private int max;

        public MinMax(int min, int max) {
            this.min = min;
            this.max = max;
        }

        public int getMin() {
            return this.min;
        }

        public int getMax() {
            return this.max;
        }
    }

    private static List<MinMax> getTemperatures(String line) {
        List<MinMax> minMaxList = new ArrayList<>(10);

        StringTokenizer tokenizer = new StringTokenizer(line, "|");
        System.out.println(tokenizer.nextToken().trim());  //prints out Temperature
        while(tokenizer.hasMoreTokens()) {
            int minimum = Integer.valueOf(tokenizer.nextToken().trim());
            int maximum = Integer.valueOf(tokenizer.nextToken().trim());
            minMaxList.add(new MinMax(minimum, maximum));
            System.out.println("Day " + (minMaxList.size()) + ": Minimum: " + minimum + " Maximum: " + maximum);
        }

        return minMaxList;
    }

    public static void main(String[] args) {
        getTemperatures("| Temperature | 30|32 | 29|30 | 25|28 | 25|29 | 27|31 | 28|32 | 26|30 | 24|32 | 24|41 | 27|32 |");
    }
}

我不确定你希望如何将温度保存在二维数组中，所以要为它创建一个专用类并返回列表中的所有内容。然后，您可以获取此列表，并根据需要将其放入数组结构中。

另请注意，我使用trim()删除了数字周围的空白。这可以防止您获得NumberFormatException。

尝试将文本文件读入2D数组并打印到屏幕

1 个答案: