如何遍歷HashSet並返回帶有限定元素的集合？

Question

我想要做的是從包含500,000英文單詞的文本文件中讀取並將其存儲到HashSet以達到性能目的。然後我想返回一個包含合格元素的HashSet，例如5個字母的單詞，6個字母的單詞等。

這是我的代碼，至今我不知道該怎麼做。 我很感謝你的解決方案！

private static HashSet<String> readPuzzleFile(int wordLength) { 
     HashSet<String> unProcessedPuzzle = new HashSet<String>(); 
     try (Scanner file = new Scanner(new File(PATHTOPUZZLE))) { 
      while (file.hasNextLine()) { 
       unProcessedPuzzle.add(file.nextLine()); 
      } 
     } catch (FileNotFoundException e) { 
      System.out.println("No Puzzle File Found!"); 
      return null; 
     } 
     HashSet<String> puzzle = new HashSet<String>(); 
     Iterator iterator = unProcessedPuzzle.iterator(); 
     for (String word : unProcessedPuzzle){ 
      puzzle.addAll(word); 
     } 
     } 

Answer 1

private static HashSet<String> readPuzzleFile(int wordLength) { 
     HashSet<String> unProcessedPuzzle = new HashSet<String>(); 
     try (Scanner file = new Scanner(new File(PATHTOPUZZLE))) { 
      while (file.hasNextLine()) { 
       unProcessedPuzzle.add(file.nextLine()); 
      } 
     } catch (FileNotFoundException e) { 
      System.out.println("No Puzzle File Found!"); 
      return null; 
     } 
     HashSet<String> puzzle = new HashSet<String>(); 
     Iterator iterator = unProcessedPuzzle.iterator(); 
     for (String word : unProcessedPuzzle){ 
      puzzle.add(word); //........addAll -> add......... 
     } 
     return puzzle;//........return puzzle......... 
     }