使用 Google Data API for Java 更新 Picasa 上的元数据

Question

我正在使用 Google Data API 从 Android 连接 Picasa。要检索图片和元数据，它效果很好，但是在解析 PATCH 的响应（相对于原始）时，我得到了 IllegalArgumentException。尽管 parseAsString 方法的输出提供了完美的 xml 字符串，但标头是“text/html”。这是一个错误还是我需要为“text/html”创建自己的解析器？

我也不介意使用 PUT 方法进行更新，有没有人有一个很好的例子如何使用 Java 进行更新？

这里是例外：

Uncaught handler: thread main exiting due to uncaught exception
 java.lang.IllegalArgumentException: No parser defined for Content-Type: text/html; charset=UTF-8
 at com.google.api.client.http.HttpResponse.parseAs(HttpResponse.java:277)
 at com.unimelb.pt3.external.google.api.Entry.executePatchRelativeToOriginal(Entry.java:95)
 at com.unimelb.pt3.external.google.api.PhotoEntry.executePatchRelativeToOriginal(PhotoEntry.java:67)
 at com.unimelb.pt3.Picasa.updatePicture(Picasa.java:135)
 at com.unimelb.pt3.Tools.updatePictureOnPicasa(Tools.java:209)
 at com.unimelb.pt3.ui.WaterfallView.onDraw(WaterfallView.java:145)
 at android.view.View.draw(View.java:6535)
 at android.view.ViewGroup.drawChild(ViewGroup.java:1531)
 at android.view.ViewGroup.dispatchDraw(ViewGroup.java:1258)
 at android.view.ViewGroup.drawChild(ViewGroup.java:1529)
 at android.view.ViewGroup.dispatchDraw(ViewGroup.java:1258)
 at android.view.View.draw(View.java:6538)
 at android.widget.FrameLayout.draw(FrameLayout.java:352)
 at android.view.ViewGroup.drawChild(ViewGroup.java:1531)
 at android.view.ViewGroup.dispatchDraw(ViewGroup.java:1258)
 at android.view.ViewGroup.drawChild(ViewGroup.java:1529)
 at android.view.ViewGroup.dispatchDraw(ViewGroup.java:1258)
 at android.view.View.draw(View.java:6538)
 at android.widget.FrameLayout.draw(FrameLayout.java:352)
 at com.android.internal.policy.impl.PhoneWindow$DecorView.draw(PhoneWindow.java:1830)
 at android.view.ViewRoot.draw(ViewRoot.java:1349)
 at android.view.ViewRoot.performTraversals(ViewRoot.java:1114)
 at android.view.ViewRoot.handleMessage(ViewRoot.java:1633)
 at android.os.Handler.dispatchMessage(Handler.java:99)
 at android.os.Looper.loop(Looper.java:123)
 at android.app.ActivityThread.main(ActivityThread.java:4363)
 at java.lang.reflect.Method.invokeNative(Native Method)
 at java.lang.reflect.Method.invoke(Method.java:521)
 at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:860)
 at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618)
 at dalvik.system.NativeStart.main(Native Method)

这里是条目中的代码：

Entry executePatchRelativeToOriginal(HttpTransport transport, Entry original)
  throws IOException {
      HttpRequest request = transport.buildPatchRequest();
      request.setUrl(getEditLink());
      request.headers.ifMatch = etag;
      AtomPatchRelativeToOriginalContent content =
          new AtomPatchRelativeToOriginalContent();
      content.namespaceDictionary = Util.NAMESPACE_DICTIONARY;
      content.originalEntry = original;
      content.patchedEntry = this;
      request.content = content;
      Log.i(Prototype.TAG, request.url.toString());
      HttpResponse response = request.execute();
      // Log.i(Prototype.TAG, response.parseAsString());
      return response.parseAs(getClass());
}

这里是主活动的相关代码：

public void updatePicture(String url, String description, String[] tags) throws IOException {
    PhotoEntry photo = photos.get(url);
    PhotoEntry patched = photo.clone();
    patched.summary = description;
    String keywords = "";
    for(int i=0; i<tags.length; i++) {
        keywords += tags[i] + ((i==tags.length-1) ? "" : ", ");
    }
    patched.mediaGroup.keywords = keywords;
    photo = patched.executePatchRelativeToOriginal(transport, photo);
}

private HttpTransport setUpTransport() {
    HttpTransport transport = GoogleTransport.create();
    GoogleHeaders headers = (GoogleHeaders) transport.defaultHeaders;
    headers.setApplicationName("google-picasaatomsample-1.0");
    headers.gdataVersion = "2";
    AtomParser parser = new AtomParser();
    parser.namespaceDictionary = Util.NAMESPACE_DICTIONARY;
    transport.addParser(parser);
    return transport;
}

编辑： 我向 setUpTransport 方法添加了以下几行：

   XmlHttpParser p2 = new XmlHttpParser();
   p2.contentType = "text/html";
   p2.namespaceDictionary = Util.NAMESPACE_DICTIONARY;
   transport.addParser(p2); 

这会导致该日志出现另一个 IllegalArgumentException：

 Uncaught handler: thread main exiting due to uncaught exception
 java.lang.IllegalArgumentException: expected start of XML element, but got something else (event type 4)
     at com.google.api.client.xml.Xml.parseElementInternal(Xml.java:180)
     at com.google.api.client.xml.Xml.parseElement(Xml.java:152)
     at com.google.api.client.xml.XmlHttpParser.parse(XmlHttpParser.java:73)
     at com.google.api.client.http.HttpResponse.parseAs(HttpResponse.java:280)
     at com.unimelb.pt3.external.google.api.Entry.executePatchRelativeToOriginal(Entry.java:95)
     at com.unimelb.pt3.external.google.api.PhotoEntry.executePatchRelativeToOriginal(PhotoEntry.java:67)
     at com.unimelb.pt3.Picasa.updatePicture(Picasa.java:130)
     at com.unimelb.pt3.Tools.updatePictureOnPicasa(Tools.java:209)
     at com.unimelb.pt3.ui.WaterfallView.onDraw(WaterfallView.java:145)
     at android.view.View.draw(View.java:6535)
     at android.view.ViewGroup.drawChild(ViewGroup.java:1531)
     at android.view.ViewGroup.dispatchDraw(ViewGroup.java:158)
     at android.view.ViewGroup.drawChild(ViewGroup.java:1529)
     at android.view.ViewGroup.dispatchDraw(ViewGroup.java:1258)
     at android.view.View.draw(View.java:6538)
     at android.widget.FrameLayout.draw(FrameLayout.java:352)
     at android.view.ViewGroup.drawChild(ViewGroup.java:1531)
     at android.view.ViewGroup.dispatchDraw(ViewGroup.java:1258)
     at android.view.ViewGroup.drawChild(ViewGroup.java:1529)
     at android.view.ViewGroup.dispatchDraw(ViewGroup.java:1258)
     at android.view.View.draw(View.java:6538)
     at android.widget.FrameLayout.draw(FrameLayout.java:352)
     at com.android.internal.policy.impl.PhoneWindow$DecorView.draw(PhoneWindow.java:1830)
     at android.view.ViewRoot.draw(ViewRoot.java:1349)
     at android.view.ViewRoot.performTraversals(ViewRoot.java:1114)
     at android.view.ViewRoot.handleMessage(ViewRoot.java:1633)
     at android.os.Handler.dispatchMessage(Handler.java:99)
     at android.os.Looper.loop(Looper.java:123)
     at android.app.ActivityThread.main(ActivityThread.java:4363)
     at java.lang.reflect.Method.invokeNative(Native Method)
     at java.lang.reflect.Method.invoke(Method.java:521)
     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:860)
     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618)
     at dalvik.system.NativeStart.main(Native Method)

Answer 1

尝试使用 XmlHttpParser 并设置其 内容类型 为“text/html”。

顺便说一句，为了响应 PATCH，Picasa 数据 API 应返回内容类型“application/xml”，而不是“text/html”。所以这可能是一个错误。

编辑：我自己没有调查过这个问题，但我怀疑这个 IllegalArgumentException 是因为 text/html 内容不是格式良好的 XML 内容。我们实际上没有 HTML 解析器。我想知道为什么你觉得你需要解析 HTML 响应，因为 parseAsString 可以满足你的需要。顺便说一句，Picasa Data API 不应该返回 HTML 响应，因此这可能是他们的错误（除了提交错误报告之外，您没有什么可以做的）。

免责声明：我是 google-api-java-client 项目。