Question

我想創建一個新文檔，並更新內容到它。在過去的兩天中，我有時成功地更新了文檔的標題，但沒有更新內容。我得到這個錯誤：

com.google.gdata.util.PreconditionFailedException: Mismatch: etags = ["GEIJRhlABSt7ImBr"], version = [gqdjfe36] 
<errors xmlns='http://schemas.google.com/g/2005'><error><domain>GData</domain><code>etagsMismatch</code><internalReason>Mismatch: etags = ["GEIJRhlABSt7ImBr"], version = [gqdjfe36]</internalReason></error></errors> 

    at com.google.gdata.client.http.HttpGDataRequest.handleErrorResponse(HttpGDataRequest.java:606) 
    at com.google.gdata.client.http.GoogleGDataRequest.handleErrorResponse(GoogleGDataRequest.java:563) 
    at com.google.gdata.client.http.HttpGDataRequest.checkResponse(HttpGDataRequest.java:552) 
    at com.google.gdata.client.http.HttpGDataRequest.execute(HttpGDataRequest.java:530) 
    at com.google.gdata.client.http.GoogleGDataRequest.execute(GoogleGDataRequest.java:535) 
    at com.google.gdata.client.Service.update(Service.java:1563) 
    at com.google.gdata.client.Service.update(Service.java:1530) 
    at com.google.gdata.client.GoogleService.update(GoogleService.java:583) 
    at com.google.gdata.client.media.MediaService.update(MediaService.java:484) 
    at com.google.gdata.data.BaseEntry.update(BaseEntry.java:639) 
    at GoogleDocuments.main(GoogleDocuments.java:51) 
Exception in thread "main" java.lang.NullPointerException 
    at GoogleDocuments.main(GoogleDocuments.java:60) 

今天早上，我試了相同的代碼，我成功地更新了文檔的標題和內容。這實在是不可預測的。 我花了幾個小時，我仍然不明白是什麼錯。

謝謝你幫我

大衛

Java代碼：

import java.io.IOException; 
import java.net.URL; 

import com.google.gdata.client.docs.DocsService; 
import com.google.gdata.data.docs.DocumentListEntry; 
import com.google.gdata.util.AuthenticationException; 
import com.google.gdata.util.ServiceException; 


import com.google.gdata.data.PlainTextConstruct; 
import com.google.gdata.data.docs.*; 
import com.google.gdata.data.media.MediaByteArraySource; 

public class GoogleDocuments { 

    /** 
    * @param args 
    */ 
    public static void main(String[] args) { 

     DocsService client = new DocsService("uop-test-v1"); 

     try { 
      client.setUserCredentials("myemail...@gmail.com", "mypassword"); 
     } catch (AuthenticationException e) { 
      // TODO Auto-generated catch block 
      e.printStackTrace(); 
     } 

     DocumentListEntry createdEntry = null; 

     // Create an empty word processor document 
     try { 
      createdEntry = createNewDocument("NewDocTitle", client); 
     } catch (IOException e2) { 
      // TODO Auto-generated catch block 
      e2.printStackTrace(); 
     } catch (ServiceException e2) { 
      // TODO Auto-generated catch block 
      e2.printStackTrace(); 
    } 

     System.out.println("Document now online @ :" + createdEntry.getHtmlLink().getHref()); 
     System.out.println("Title of the document :" + createdEntry.getTitle().getPlainText()); 

     createdEntry.setTitle(new PlainTextConstruct("NewTitle")); 

     DocumentListEntry updatedEntry = null; 

     try { 
      updatedEntry = createdEntry.update(); 
     } catch (IOException e) { 
      // TODO Auto-generated catch block 
      e.printStackTrace(); 
     } catch (ServiceException e) { 
      // TODO Auto-generated catch block 
      e.printStackTrace(); 
     } 

     System.out.println("New title of the document :" +updatedEntry.getTitle().getPlainText()); 

     updatedEntry.setMediaSource(new MediaByteArraySource("updated content".getBytes(), "text/plain")); 

     try { 
      updatedEntry.updateMedia(true); 
     } catch (IOException e) { 
      // TODO Auto-generated catch block 
      e.printStackTrace(); 
     } catch (ServiceException e) { 
      // TODO Auto-generated catch block 
      e.printStackTrace(); 
     } 

     System.out.println("Document updated!"); 
    } 

    static public DocumentListEntry createNewDocument(String title, DocsService client) throws IOException, ServiceException { 
     DocumentListEntry newEntry = null; 
     newEntry = new DocumentEntry(); 
     newEntry.setTitle(new PlainTextConstruct(title)); 
     return client.insert(new URL("http://docs.google.com/feeds/default/private/full"), newEntry); 
    } 
} 

Answer 1

谷歌文檔跟蹤版本使用的ETag文件的信息。 當您收到此錯誤時，表示文件內容/元內容已更改。一種可能的解決方法是再次獲取資源。

看一看http://www.google.com/support/forum/p/apps-apis/thread?tid=2f5f76354541137b&hl=en