6

所以我试图从存储在网络服务器上的文件中下载和加载一个对象。我使用的代码在 AsyncTask 的 try-catch 块中：

URL url = new URL("http://www.mydomain.com/thefileIwant");
URLConnection urlConn = url.openConnection();
ObjectInputStream ois = new ObjectInputStream(urlConn.getInputStream());
foo = (Foo) ois.readObject();
ois.close();

我使用以下代码构建文件：

ObjectOutputStream oos = new ObjectOutputStream(new FileOutputStream("thefileIwant"));
oos.writeObject(foo);
oos.close();

当我尝试读取第一段代码中的对象时，我得到一个 IOExecption，表明 UTF 数据格式与 UTF-8 不匹配。我试过几次重新构建文件，它总是给我同样的错误。我可以下载这样的对象吗？

4

3 回答 3

1

这看起来像一个编码问题。我认为 kichik 是正确的，并且很可能您的服务器使用错误的内容类型发送数据，但我认为您需要将其设置为application/x-java-serialized-object。尝试在打开 URLConnection 后立即添加以下行：

urlConn.setUseCaches(false);
urlConn.setRequestProperty("Content-Type", "application/x-java-serialized-object");

如果这不起作用（您的服务器可能无法使用该类型发送它），您可以尝试使用 Socket 而不是 UrlConnection，或者使用 XML 或 JSON 序列化您的对象并通过 HttpUrlConnection 获取

于 2012-05-18T13:19:30.850 回答
0

试试这个。它与您的代码相似，但有一些不同之处。顺序读/写可能有点过时，但对我来说效果很好。

  URL url = new URL("your URL");
  HttpURLConnection urlConn = (HttpURLConnection) url.openConnection();
  urlConn.setRequestMethod("GET");
  urlConn.setRequestProperty("Content-Type", "text/plain; charset=utf-8");
  urlConn.connect();
  InputStream is = urlConn.getInputStream();
  byte[] buffer = new byte[1024];
  int numRead = 0;
  FileOutputStream fos = new FileOutputStream("Your File");
  while ((numRead = is.read(buffer)) > 0) {
    fos.write(buffer, 0, numRead);
  }
  fos.close();
于 2012-05-21T18:58:39.480 回答
0

这对我们有用，使用一些 Apache 库

        FileOutputStream fos = new FileOutputStream("Your File");
        HttpParams params = new BasicHttpParams();
        HttpProtocolParams.setVersion(params, HttpVersion.HTTP_1_1);
        HttpProtocolParams.setContentCharset(params, HTTP.UTF_8);
        SchemeRegistry registry = new SchemeRegistry();
        registry.register(new Scheme("http", PlainSocketFactory.getSocketFactory(), 80));

        ClientConnectionManager ccm = new ThreadSafeClientConnManager(params, registry);

        HttpClient client =  new DefaultHttpClient(ccm, params);


        HttpGet httpGet = new HttpGet(downloadURL);
        try {
        HttpResponse response = client.execute(httpGet);
        StatusLine statusLine = response.getStatusLine();
        int statusCode = statusLine.getStatusCode();
        Log.d(LOG_TAG, "code is " + statusCode);
        if (statusCode == 200) {
            HttpEntity entity = response.getEntity();
            InputStream content = entity.getContent();

            byte[] buffer = new byte[1024];
            int len1 = 0;
            while ( (len1 = content.read(buffer)) > 0 ) {
                fos.write(buffer,0, len1);
         }                              

         success = true;
        } else {
            Log.e(LOG_TAG_JSON, "Failed to download file " + downloadURL);
        }
        if (null != response.getEntity())
        {
            response.getEntity().consumeContent();
        }
    } catch (ClientProtocolException e) {
        e.printStackTrace();
    } catch (IOException e) {
        Log.e(LOG_TAG, "downloadVersion " + e.toString());
        e.printStackTrace();
    }
于 2012-05-24T21:49:01.283 回答