Which bit represents which TCP flag

I've had the same issue myself and found the answer at Wireshark Q&A:

You can make Wireshark show the HTTP response straight away by disabling the "Allow Subdissector to reassemble TCP streams" in the TCP protocol preferences" (you need to restart Wireshark after disabling the option).

Window size at zero means the OS has received all the data it can in its receive buffer for this connection and is waiting for the application to read() it. In other words, if you don't read the data the server is sending you, as fast as it's sending it, at some point it will block like this. How are you using wget, can you paste the exact script/command? Same with your java program, are you sure it's reading all the data from the server, and never getting backed up, or missing an event/notification that data is ready, or having a problem where it can't keep up with its read()s?

Also, check netstat -anp and look at the Recv-Q column for this connection, if it's not 0 then there's data buffered up, waiting for your app to read it. Edit: argh, Windows, this link might help.