のJavaソートは

Question

電流出力ファイル。

どのようにすれば、最初に最も高いマークでソートし、次に最も低い試行にするようにしますか？例xxxxxは、6,1、xxxxは、6,1 xxxxは、6,4、.....

ヘルプ!!!!!!何時間も立ち往生！

public static void sort() { 
    BufferedReader reader = null; 
    try { 
     reader = new BufferedReader(new FileReader("data.csv")); 
    } catch (FileNotFoundException e) { 
     // TODO Auto-generated catch block 
     e.printStackTrace(); 
    } 
    Map < String, List <String>> map = new TreeMap < String, List <String>>(); 
    String line; 
    try { 
     line = reader.readLine(); 
    } catch (IOException e) { 
     // TODO Auto-generated catch block 
     e.printStackTrace(); 
    } //read header 
    try { 
     while ((line = reader.readLine()) != null) { 
      String key = getField(line); 

      List <String> l = map.get(key); 

      if (l == null) { 
       l = new LinkedList <String>(); 
       map.put(key, l); 
      } 
      l.add(line); 
     } 
    } catch (IOException e) { 
     // TODO Auto-generated catch block 
     e.printStackTrace(); 
    } 
    try { 
     reader.close(); 
    } catch (IOException e1) { 
     // TODO Auto-generated catch block 
     e1.printStackTrace(); 
    } 

    System.out.println("HALL OF FAME\nMatric, Marks, Attempt"); 
    map = ((TreeMap < String, List <String>>) map).descendingMap(); 

    for (List <String> list: map.values()) { 
     for (String val: list) { 
      System.out.println(val); 
     } 
    } 
} 


private static String getField(String line) { 
    return line.split(",")[1]; // extract value you want to sort on 
} 

Answer 1

動作しているようです！

public static void sort() throws FileNotFoundException { 
    BufferedReader reader; 
    try { 
     reader = new BufferedReader(new FileReader("data.csv")); 
    } catch (FileNotFoundException e) { 
     // TODO Auto-generated catch block 
     e.printStackTrace(); 
     throw e; 
    } 
    Map<MarkAndAttempt, List<String>> map = 
      new TreeMap<MarkAndAttempt, List<String>>(new Comparator<MarkAndAttempt>() { 
       @Override 
       public int compare(MarkAndAttempt o1, MarkAndAttempt o2) { 
        if (o1.getMark() > o2.getMark()) { 
         return -1; 
        } else if (o1.getMark() == o2.getMark()) { 
         return o1.getAttempt() > o2.getAttempt() ? 1 : -1; 
        } else { 
         return 1; 
        } 
       } 
      }); 
    String line; 
    try { 
     reader.readLine(); 
    } catch (IOException e) { 
     // TODO Auto-generated catch block 
     e.printStackTrace(); 
    }//read header 
    try { 
     while ((line = reader.readLine()) != null) { 
      //String key = getField(line); 

      //List<String> l = map.get(key); 

      MarkAndAttempt markAndAttempt = generateMarkAndAttempt(line); 
      List<String> l = map.get(markAndAttempt); 

      if (l == null) { 
       l = new LinkedList<String>(); 
       map.put(markAndAttempt, l); 
      } 
      l.add(line); 
     } 
    } catch (IOException e) { 
     // TODO Auto-generated catch block 
     e.printStackTrace(); 
    } 
    try { 
     reader.close(); 
    } catch (IOException e1) { 
     // TODO Auto-generated catch block 
     e1.printStackTrace(); 
    } 

    System.out.println("HALL OF FAME\nMatric, Marks, Attempt"); 

    for (List<String> list : map.values()) { 
     for (String val : list) { 
      System.out.println(val); 
     } 



    } 
} 


private static MarkAndAttempt generateMarkAndAttempt(String line) { 
    Objects.requireNonNull(line); 
    String[] parts = line.split(","); 
    if (parts.length != 3) throw new IllegalArgumentException(""); 
    return new MarkAndAttempt(Integer.valueOf(parts[1].trim()), Integer.valueOf(parts[2].trim())); 
} 

private static String getField(String line) { 
    return line.split(",")[1];// extract value you want to sort on 
} 

static class MarkAndAttempt { 

    private int mark; 

    private int attempt; 

    public MarkAndAttempt(int mark, int attempt) { 
     this.mark = mark; 
     this.attempt = attempt; 
    } 

    public int getMark() { 
     return mark; 
    } 

    public void setMark(int mark) { 
     this.mark = mark; 
    } 

    public int getAttempt() { 
     return attempt; 
    } 

    public void setAttempt(int attempt) { 
     this.attempt = attempt; 
    } 

    @Override 
    public boolean equals(Object o) { 
     if (this == o) return true; 
     if (o == null || getClass() != o.getClass()) return false; 

     MarkAndAttempt that = (MarkAndAttempt) o; 

     return mark == that.mark; 

    } 

    @Override 
    public int hashCode() { 
     return mark; 
    } 
}