Sending xml over http

Question

I have a WLS 6.0 servlet that receives XML transactions via a post method.
          Code snippet as follows:
          public void doPost(HttpServletRequest req, HttpServletResponse res)
          throws ServletException, IOException
          int txContentLength = req.getContentLength();
          //get entire input xml stream and store in a stringbuffer
          InputStream inp = req.getInputStream();
          BufferedReader br = new BufferedReader(new InputStreamReader(inp));
          byte[] ba = new byte[txContentLength];
          System.out.println("Reading...");
          int bytesRead = inp.read(ba);
          System.out.println("bytesRead= " + bytesRead);
          while(bytesRead < txContentLength) {
          int moreRead = inp.read(ba, bytesRead, (ba.length - bytesRead));
          if(moreRead == -1)
          break;
          bytesRead += moreRead;
          System.out.println("finished reading buffer...");
          StringBuffer sb = new StringBuffer(new String(ba));
          I have a java client on my PC that takes an XML file as input and sends the
          information to the servlet without any problems.
          The problem is a client that is connecting to our network via a T1
          connection. When they send transactions, about 1 out of every 4
          transactions makes it past the "Reading..." statement above. The other
          transactions appear to 'hang' when it hits the inp.read(ba) line above.
          From all indications, that servlet's execute thread appears 'hung' as if the
          inp.read() is waiting forever.
          I've tried using readLine() on the InputStream() and my local client program
          is unaffected - it works OK. The remote client is having problems using
          either method. The only difference I've noted with the remote client is
          that they are using HTTP 1.0 and I'm using HTTP 1.1. Initially, their
          mime-type was null but they've changed it to text/xml and no luck. I've
          even sent them my client code that is working and they are still having
          problems...
          Another strange anomoly is that req.getContentLength() is returning a valid
          number on the transactions that fail. For example, I had some debug code
          that showed the content length and it was always something like 4012 or
          3500, etc. Not -1 as I would expect...
          Has anyone run into this problem with receiving XML transactions?
          Thanks
          Rob Mason
          

Answer 1

Thanks for the suggestion - I went back and added a check on the
          contentLength to make sure it had a valid number before trying to call any
          'read' methods... still no luck.
          I did go in and put a try/catch around the read() logic below. The
          exception thrown is an InterruptedIOException. The docs say that this is
          thrown 'to indicate that an input or output transfer has been terminated
          because the thread performing it was terminated.'
          This would seem to indicate that WLS is having the problem - not the client?
          Via the console, under the Configuration section, my HTTP section has the
          following values:
          POST timeout secs: 10
          Max POST time: 10
          Max POST size: -1
          Is there anything else I can try on the server level?
          Thanks
          Rob Mason
          "Xiang Rao" <[email protected]> wrote in message
          news:[email protected]...
          >
          > T1 shouldn't be the problem. We even use dialup to upload file via HTTP
          POST. HTTP
          > 1.0 shouldn't be problem. If you think this is the only difference, you
          can ask
          > other developers to change it to HTTP 1.1 when they request your servlet.
          >
          > The hang at read(ba) most likely means no request data are sent to your
          servlet
          > even if you think there should be some data. In your code, you are better
          to add
          > a block to check if the content_length is GREATER THAN 0 (-1 or 0), if
          not, you
          > shouldn't open any inputstream and shouldn't call any read method. If the
          content_length
          > is 0, your character buffer will have length 0 and I really don't know
          what you
          > can put into such buffer. It is not necessary to set a buffer with the
          length
          > of expected Content_Length. Since you use BufferedReader, you can create a
          buffere
          > with large enough size (see 1K, 8K, 16K, etc)and the return value of read
          will
          > give you the exact length you get for each read call, then append result
          to your
          > Stringbuffer. On the other hand, it is better for you to handle
          IOException in
          > your servlet.
          >
          > Ask the other side developers to send you their client code and compare
          their
          > code with your test code word by word. Check how they compute the
          Content_Length
          > and how they send Content_Length field to you. If this field is not
          explicitly
          > set, I think you should get -1 or 0, even there are request data out. Also
          you
          > should check how the data are sent out to make sure they really send you
          request
          > data.
          >
          >
          >
          >
          > "Rob Mason" <[email protected]> wrote:
          > >I have a WLS 6.0 servlet that receives XML transactions via a post
          method.
          > >Code snippet as follows:
          > >
          > > public void doPost(HttpServletRequest req, HttpServletResponse res)
          > > throws ServletException, IOException
          > > {
          > > int txContentLength = req.getContentLength();
          > >
          > > //get entire input xml stream and store in a stringbuffer
          > > InputStream inp = req.getInputStream();
          > > BufferedReader br = new BufferedReader(new InputStreamReader(inp));
          > >
          > > byte[] ba = new byte[txContentLength];
          > > System.out.println("Reading...");
          > > int bytesRead = inp.read(ba);
          > > System.out.println("bytesRead= " + bytesRead);
          > > while(bytesRead < txContentLength) {
          > > int moreRead = inp.read(ba, bytesRead, (ba.length - bytesRead));
          > > if(moreRead == -1)
          > > break;
          > > bytesRead += moreRead;
          > > }
          > >
          > > System.out.println("finished reading buffer...");
          > > StringBuffer sb = new StringBuffer(new String(ba));
          > >}
          > >
          > >
          > >I have a java client on my PC that takes an XML file as input and sends
          > >the
          > >information to the servlet without any problems.
          > >The problem is a client that is connecting to our network via a T1
          > >connection. When they send transactions, about 1 out of every 4
          > >transactions makes it past the "Reading..." statement above. The other
          > >transactions appear to 'hang' when it hits the inp.read(ba) line above.
          > >From all indications, that servlet's execute thread appears 'hung' as
          > >if the
          > >inp.read() is waiting forever.
          > >
          > >I've tried using readLine() on the InputStream() and my local client
          > >program
          > >is unaffected - it works OK. The remote client is having problems using
          > >either method. The only difference I've noted with the remote client
          > >is
          > >that they are using HTTP 1.0 and I'm using HTTP 1.1. Initially, their
          > >mime-type was null but they've changed it to text/xml and no luck. I've
          > >even sent them my client code that is working and they are still having
          > >problems...
          > >
          > >Another strange anomoly is that req.getContentLength() is returning a
          > >valid
          > >number on the transactions that fail. For example, I had some debug
          > >code
          > >that showed the content length and it was always something like 4012
          > >or
          > >3500, etc. Not -1 as I would expect...
          > >
          > >Has anyone run into this problem with receiving XML transactions?
          > >
          > >Thanks
          > >Rob Mason
          > >
          > >
          > >
          >