通過對異常獲取連接復位（TopLink的）

Question

我使用下面的代碼，以確保文件內容被成功寫入磁盤

public void copyFileFromUrl(URL source, File target, int count) throws IOException { 

    InputStream in = null; 
    OutputStream out = null;  
    if (target != null) { 
     try { 
      if (!target.exists()) { 
       target.createNewFile(); 
       if (source == null) { 
        return; 
       } else {  
        in = source.openStream(); 
       } 
       out = new FileOutputStream(target); 
       byte[] buf = new byte[1024]; 
       int len; 
       while ((len = in.read(buf)) > 0) { 
        out.write(buf, 0, len); 
       }    
       log.debug("The contents from the URL: " + source + " are successfully written to the file " + target);    
       //add for successfull 
      } else { 
       log.debug("skipping creation of asset"); 
      } 
     } catch (Exception e) { 
      if(count < 3){ 
       if (in != null) { 
        in.close(); 
       } 
       if (out != null) { 
        out.close(); 
       } 

       // Attempt to delete it 
       boolean success = target.delete(); 
       if (!success) { 
        log.debug("Unable to delete " + target);  
       } else {  
        copyFileFromUrl(source, target, ++count); 
       }  
      } else {  
       log.debug(e.getClass().getName()); 
       e.printStackTrace();    
      }  
     } finally { 
      if (in != null) { 
       in.close(); 
      } 
      if (out != null) { 
       out.close(); 
      }  
     } 
    } 
} 

我打電話這段代碼這樣

while(iter.hasNext()) { 
    CourseMaterials cm = iter.next();  
    String url; 
    try { 
     Asset asset = cm.getAsset(); 
     List<AssetVersion> av = asset.getAssetVersions(); 

    } catch (Exception e1) { 
     log.debug("Bad asset so skipping..."); 
     e1.printStackTrace(); 
     continue; 
    } 

    .... 

    try { 
     URL earl = new URL(visualElementURL); 
     scormFileWriter.copyFileFromUrl(earl, new File(absoluteFileName), 0); 
    } catch (Exception e) { 
     e.printStackTrace(); 
     return false; 
    } 
} 

現在我試圖如何，當我來功能copyFileFromUrl()，我拔掉電纜，它嘗試兩次，然後在第三次我插入電纜。該函數成功返回。因爲我在while循環中。現在之後，當我來到線

Asset asset = cm.getAsset(); 

我得到Connection Reset by peer exception。它跳過這個資產，然後再次正常啓動。爲什麼？爲什麼我得到connection Reset by peer exception？如果我因爲拔掉電纜而得到這個異常，那麼我也應該爲所有其他資產得到它，但我只是爲了下一次迭代纔得到這個異常，然後它開始工作正常，我的意思是然後行Asset asset = cm.getAsset();投擲後不拋出異常第一次？

爲什麼會發生這種情況？我如何克服它？

我正在使用SQL Server 2008 for數據庫。

感謝

Answer 1

您可以嘗試使用flush（）方法之前close（）方法