試圖一次寫入多個文件 - Java

Question

我想分割一個字典文件，我有不同長度的多個字典，例如，如果我想把它放到長度爲2,3,4的小字典中，..... n，我可以在那裏更快地搜索它們。當我說得更快時，我的意思是我會知道輸入長度，因此訪問相應的長度字典（一小部分）將意味着更快的訪問。這是我目前的實現，它可以生成文件，但不會像我所希望的那樣寫入它們。理想情況下，所有長度爲2的單詞都將寫入length2文本文件。任何人有任何建議？

import java.io.BufferedReader; 
import java.io.FileNotFoundException; 
import java.io.FileReader; 
import java.io.PrintWriter; 
import java.io.IOException; 

public class Main { 

public static void main(String[] args) throws IOException { 
    FileReader fr = new FileReader("dictionary.txt"); 
    PrintWriter l2 = new PrintWriter("dictionary_length2.txt", "UTF-8"); 
    PrintWriter l3 = new PrintWriter("dictionary_length3.txt", "UTF-8"); 
    PrintWriter l4 = new PrintWriter("dictionary_length4.txt", "UTF-8"); 
    PrintWriter l5 = new PrintWriter("dictionary_length5.txt", "UTF-8"); 
    PrintWriter l6 = new PrintWriter("dictionary_length6.txt", "UTF-8"); 
    PrintWriter l7 = new PrintWriter("dictionary_length7.txt", "UTF-8"); 
    PrintWriter l8 = new PrintWriter("dictionary_length8.txt", "UTF-8"); 
    PrintWriter l9 = new PrintWriter("dictionary_length9.txt", "UTF-8"); 
    PrintWriter l10 = new PrintWriter("dictionary_length10.txt", "UTF-8"); 
    PrintWriter l11 = new PrintWriter("dictionary_lengty11.txt", "UTF-8"); 
    PrintWriter l12 = new PrintWriter("dictionary_length12.txt", "UTF-8"); 
    PrintWriter l13 = new PrintWriter("dictionary_length13.txt", "UTF-8"); 
    PrintWriter l14 = new PrintWriter("dictionary_length14.txt", "UTF-8"); 
    PrintWriter l15 = new PrintWriter("dictionary_length15.txt", "UTF-8"); 
    PrintWriter l16 = new PrintWriter("dictionary_length16.txt", "UTF-8"); 
    PrintWriter l17 = new PrintWriter("dictionary_length17.txt", "UTF-8"); 
    PrintWriter l18 = new PrintWriter("dictionary_length18.txt", "UTF-8"); 
    PrintWriter l19 = new PrintWriter("dictionary_length19.txt", "UTF-8"); 
    PrintWriter l20 = new PrintWriter("dictionary_length20.txt", "UTF-8"); 
    PrintWriter l21 = new PrintWriter("dictionary_length21.txt", "UTF-8"); 

    BufferedReader tr = new BufferedReader(fr); 
    String temp; 
    int temp_length; 

    for(int i = 0; i < 60388; i++){ 
     temp = new String(tr.readLine()); 
     temp_length = temp.length(); 
     if(temp_length == 2) 
      l2.println(temp); 
     if(temp_length == 3) 
      l3.println(temp); 
     if(temp_length == 4) 
      l4.println(temp); 
     if(temp_length == 5) 
      l5.println(temp); 
     if(temp_length == 6) 
      l6.println(temp); 
     if(temp_length == 7) 
      l7.println(temp); 
     if(temp_length == 8) 
      l8.println(temp); 
     if(temp_length == 9) 
      l9.println(temp); 
     if(temp_length == 10) 
      l10.println(temp); 
     if(temp_length == 11) 
      l11.println(temp); 
     if(temp_length == 12) 
      l12.println(temp); 
     if(temp_length == 13) 
      l13.println(temp); 
     if(temp_length == 14) 
      l14.println(temp); 
     if(temp_length == 15) 
      l15.println(temp); 
     if(temp_length == 16) 
      l16.println(temp); 
     if(temp_length == 17) 
      l17.println(temp); 
     if(temp_length == 18) 
      l18.println(temp); 
     if(temp_length == 19) 
      l19.println(temp); 
     if(temp_length == 20) 
      l20.println(temp); 
     if(temp_length == 21) 
      l21.println(temp); 
    } 

    tr.close(); 
    l2.close(); 
    l3.close(); 
    l4.close(); 
    l5.close(); 
    l6.close(); 
    l7.close(); 
    l8.close(); 
    l9.close(); 
    l10.close(); 
    l11.close(); 
    l12.close(); 
    l13.close(); 
    l14.close(); 
    l15.close(); 
    l16.close(); 
    l17.close(); 
    l18.close(); 
    l19.close(); 
    l20.close(); 
    l21.close(); 
    System.out.println("Complete."); 
} 
} 

Answer 1

正切的「答案」如下。 （這應該也打印出來的內容的文件，除非我失去了一些非常基本的。）

---

每當有一組的形式xN變量（例如l2，l3，l22）他們應該通常被替換爲列表集合類型，如ArrayList。

這只是表明一個例子如何可以減少重複和固定的界限：可製成

int MAX_WORD_LEN = 22; // making this dynamic left as an excercise 
List<PrintWriter> writers = new ArrayList<PrintWriter>(); 

for (int i = 0; i <= MAX_WORD_LEN; i++) { 
    PrintWriter w = new PrintWriter("dictionary_length" + i + ".txt", "UTF-8"); 
    writers.Add(w); 
} 

String line; 
while ((line = tr.readLine()) != null) { 
    int len = line.length(); 
    if (len < writers.size()) { 
     writers.get(len).println(line); 
    } 
} 

for (PrintWriter w : writers) { 
    w.close(); 
} 

輕微的調整不創建一個「0」或「1」文件。