我怎樣才能把它變成一個循環？

Question

在Java中編寫一個LSH程序，在第一部分中，我閱讀了5個不同的文本文件，並提取了所有的獨特單詞。然後創建了5個不同的洗牌詞。現在，我提供的代碼很明顯，但是我知道，無論何時您複製粘貼相同的代碼塊很多次，您通常可以使用循環完成它更乾淨。在這種情況下，我只是不知道如何。我覺得像我這樣做是不好的習慣，所以在將來我很樂意避免這種情況。有人能幫我弄清楚如何循環Java變量名嗎？ （或類似的複製/粘貼代碼塊的一些類似的修復）

更新：我需要能夠訪問我的程序中後來每個獨特的洗牌列表，所以我不能簡單地把它放在for循環迭代5次覆蓋先前的列表。

我也不需要輸出列表，這只是測試洗牌，對不起，不清楚。我更新了我的評論。

import java.io.File; 
import java.io.FileNotFoundException; 
import java.util.*; 


public class LSH { 

    public static void main(String[] args) throws FileNotFoundException { 

     //Find all unique words in the Files in dir /filestxt 
     HashSet words = new HashSet(); 
     File dir = new File("filestxt"); 
     for (File f : dir.listFiles()) { 
      Scanner in = new Scanner(f); 

      while(in.hasNextLine()) { 
       String line = in.nextLine(); 
       words.add(line); 
      }//end while 
     }//end for 

     //Create 5 different shufflings of the words 
     LinkedList shuffle1 = new LinkedList(); 
     LinkedList shuffle2 = new LinkedList(); 
     LinkedList shuffle3 = new LinkedList(); 
     LinkedList shuffle4 = new LinkedList(); 
     LinkedList shuffle5 = new LinkedList(); 
     for (Object s : words) { 
      shuffle1.add(s.toString()); 
     }//end for 
     for (Object s : words) { 
      shuffle2.add(s.toString()); 
     }//end for 
     for (Object s : words) { 
      shuffle3.add(s.toString()); 
     }//end for 
     for (Object s : words) { 
      shuffle4.add(s.toString()); 
     }//end for 
     for (Object s : words) { 
      shuffle5.add(s.toString()); 
     }//end for 
     Collections.shuffle(shuffle1); 
     Collections.shuffle(shuffle2); 
     Collections.shuffle(shuffle3); 
     Collections.shuffle(shuffle4); 
     Collections.shuffle(shuffle5); 

     //This block for testing purposes only 
     System.out.println(shuffle1); 
     System.out.println(shuffle2); 
     System.out.println(shuffle3); 
     System.out.println(shuffle4); 
     System.out.println(shuffle5); 

    }//end main 

} 

Answer 1

public static void main(String[] args) throws FileNotFoundException { 
    HashSet<String> words = new HashSet<String>(); 
    File dir = new File("filestxt"); 
    for (File f : dir.listFiles()) { 
     Scanner in = new Scanner(f); 
     while(in.hasNextLine()) { 
      words.add(in.nextLine()); 
     }//end while 
    }//end for 

    //Create 5 different shufflings of the words 
    for (int i = 0; i < 5; i++) { 
     List<String> shuffle = new ArrayList<String>(); 
     for (String s : words) { 
      shuffle.add(s); 
     }//end for 
     Collections.shuffle(shuffle); 
     System.out.println(shuffle); 
    } 
} 

編輯：如果您想在以後訪問它，進入循環之前聲明一個變量

//Create 5 different shufflings of the words 
    List<ArrayList<String>> listOlists = new ArrayList<ArrayList<String>>(); 
    for (int i = 0; i < 5; i++) { 
     ArrayList<String> shuffle = new ArrayList<String>(); 
     for (String s : words) { 
      shuffle.add(s); 
     }//end for 
     Collections.shuffle(shuffle); 
     listOlists.add(shuffle); 
     System.out.println(shuffle); 
    } 
    //access it later 
    for (List<String> arrayList : listOlists) { 
     System.out.println(arrayList); 
    } 

Answer 2

因此，您可以使用單個shuffle（）方法簡化它，如下所示。像@fge所說，爲什麼使用原始數據類型而不是通用的？

import java.io.File; 
import java.io.FileNotFoundException; 
import java.util.*; 

public class LSH { 

    public static List<String> shuffle(Set<String> words) { 
     List<String> list = new LinkedList<String>(); 
     for (String word : words) { 
     list.add(word); 
     } 
     return list; 
    } 

    public static void main(String[] args) throws FileNotFoundException { 
     //Find all unique words in the Files in dir /filestxt 
     Set<String> words = new HashSet<String>(); 
     File dir = new File("filestxt"); 
     for (File f : dir.listFiles()) { 
     Scanner in = new Scanner(f); 

     while (in.hasNextLine()) { 
      String line = in.nextLine(); 
      words.add(line); 
     }//end while 
     }//end for 

     //Create 5 different shufflings of the words 
     List<String> shuffle1 = shuffle(words); 
     List<String> shuffle2 = shuffle(words); 
     List<String> shuffle3 = shuffle(words); 
     List<String> shuffle4 = shuffle(words); 
     List<String> shuffle5 = shuffle(words); 

     Collections.shuffle(shuffle1); 
     Collections.shuffle(shuffle2); 
     Collections.shuffle(shuffle3); 
     Collections.shuffle(shuffle4); 
     Collections.shuffle(shuffle5); 

     System.out.println(shuffle1); 
     System.out.println(shuffle2); 
     System.out.println(shuffle3); 
     System.out.println(shuffle4); 
     System.out.println(shuffle5); 
    }//end main 
}