[TechNote] PM03333: ENABLE POST DATA TO BE READ MULTIPLE TIMES.

APAR status

- Closed as program error.

Error description

It is not possible to read post data both as parameters and either using a InputStream or Reader. The second read will not receive any data. This may occur, for example, when a filter reads one or more parameters and a servlet tries to read the post data as an InputStream, or vice-versa.

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED:  IBM WebSphere Application Server Version 6.1*
  *                  and Version 7 users.                        *
  ****************************************************************
  * PROBLEM DESCRIPTION: It is not possible to read post data    *
  *                      multiple times.                         *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  As part of request processing, post data may be read either as
  parameters or using an InputStream or a Reader. However
  whichever method is used the WebContainer does a destructive
  read of the data such that the data may be read only once for
  a given request.
  

Problem conclusion

• The WebContainer has been modified to enable multiple reads of
  post data when the following WebContainer custom property is
  set to true:
  
  com.ibm.ws.webcontainer.enableMultiReadOfPostData = true
  
  With this property set the post data can be read multiple
  times as either an InputStream or Reader, and as parameters.
  
  Further, to enable post data to be re-read from the beginning
  using an InputStream or Reader, or as Parameters, the following
  sequence must be followed when using a Reader or InputStream:
  
  1. obtain the InputStream or Reader
  2. read data
  3. close the InputStrean or Reader
  
  Note that internally the WebContainer completes this sequence
  when reading parameters.
  
  If either steps 1 or 3 are not observed the next read of the
  post data will not be reset to the beginning of the data.
  
  The fix for this APAR is currently targeted for inclusion in
  fix packs 6.1.0.31 and 7.0.0.9.  Please refer to the
  Recommended Updates page for delivery information:
  http://www.ibm.com/support/docview.wss?rs=180&uid=swg27004980