duplicate requests from HttpClient

Question

I am using HttpClient 4.0.1 on android... I make a POST request with a header set that is the current millis... I see that request hit the server twice within a few millis (5-10

Answer 1

I cannot speak for HttpClient version shipped with Android, as it is effectively a fork now based on an extremely old pre-BETA snapshot. However, if you are using a stock version of Apache HttpClient 4.x, it DOES NOT automatically retry POST or PUT requests unless configured to do otherwise.

In your particular case I suspect the HTTP message gets retransmitted by the wireless driver due to loss of connectivity or similar networking issue. HTTP is not a guaranteed delivery protocol. HTTP messages can get re-sent by lower level transports. Your application must be prepared to deal with duplicate HTTP messages.