For incoming http request the content-length > 0 but request.getParameterNames is no data

When I send a http request to JBoss 5.1.0 GA by form post method and I print the all parameter names and request content-length in console, sometimes request parameter names and content-length match each other very well. But in the other occasions, content-length shows the correct result and request parameter names disappear.

I use wireshark to sniff client to make sure the http posted data 开发者_JAVA百科is correct. However, looks like the webserver side loses part of request data from time to time.

Is it probably related to the posted data's size is too large?

Do you guys know the possible reasons?