Question

I have got my android app that uses HttpClient to reach my servlet
deployed on my Tomcat. It is installed on my HTC Magic.

If I launch it when connected on Wifi : it works.
If I launch it when connected to 3G (GSM data network) : it doesn’t work but my servlet is reached. In other word, it seems that my phone never get the response :

Technical problem while receiving response.
org.apache.http.NoHttpResponseException: The target server failed to respond
   at org.apache.http.impl.conn.DefaultResponseParser.parseHead(DefaultResponseParser.java:85)
   at org.apache.http.impl.io.AbstractMessageParser.parse(AbstractMessageParser.java:174)
   at org.apache.http.impl.AbstractHttpClientConnection.receiveResponseHeader(AbstractHttpClientConnection.java:179)
   at org.apache.http.impl.conn.DefaultClientConnection.receiveResponseHeader(DefaultClientConnection.java:235)
   at org.apache.http.impl.conn.AbstractClientConnAdapter.receiveResponseHeader(AbstractClientConnAdapter.java:259)
   at org.apache.http.protocol.HttpRequestExecutor.doReceiveResponse(HttpRequestExecutor.java:279)
   at org.apache.http.protocol.HttpRequestExecutor.execute(HttpRequestExecutor.java:121)
   at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:410)
   at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:555)
   at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:487)
   at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:465)

If I use the web browser through 3G to activate the test HTML page that is packaged with my servlet, it reaches the same servlet with success (the page receives the response).

How could I debug HttpClient or ask it to dump everything ?

Does someone have a clue on what’s going on ?

Answer 1

I finally got rid of this problem : simply a HTTP header that was badly handled by a squid server on the road :

Expect: 100-Continue

It seems to be there by default with DefaultHttpClient on android SDK. To tackle this, simply add that in your code :

  HttpProtocolParams.setUseExpectContinue(httpClient.getParams(), false);