寫入文件：IOException：流關閉

Question

我無法弄清楚爲什麼我的代碼出現上述錯誤。每次調用方法時，我都會創建一個FileWriter和BufferedWriter的新實例，但顯然該流已經關閉。

public static void addSpawn(Location spawn) 
{ 
    File spawns = new File("spawns.dat"); 

    FileWriter write = null; 
    BufferedWriter out = null; 

    try 
    { 
     write = new FileWriter(spawns, true); 
     out = new BufferedWriter(write); 

     out.write(locToStr(spawn)); 
     out.newLine(); 
    } 
    catch(Exception e) 
    { 
     System.out.println("Error writing spawn file: " + e.getMessage()); 
    } 
    finally 
    { 
     if(write != null) 
     { 
      try 
      { 
       write.close(); 
      } 
      catch(Exception e) 
      { 
       e.printStackTrace(); 
      } 
     } 

     if(out != null) 
     { 
      try 
      { 
       out.close(); 
      } 
      catch(Exception e) 
      { 
       e.printStackTrace(); 
      } 
     } 
    } 
} 

任何幫助將不勝感激。

Answer 1

BufferedWriter包裝目標Writer。當你close()它，它在關閉它之前試圖flush底層目標Writer。

在你的代碼中，你調用close()對目標FileWriter調用closeBufferedWriter。當BufferedWriter#close()試圖調用FileWriter上的flush時，該FileWriter已關閉，從而引發異常。

您需要先關閉BufferedWriter。更好的是，使用try-with-resources

try (FileWriter write = new FileWriter(spawns, true); BufferedWriter out = new BufferedWriter(write);) {