Concurrent transactions in servlets using HttpConnectionURL class

Question

I have tested our application for multiple transactions i.e. concurrent transactions between two servers with IIS and Tomcat environment. We found some unexpected result and which is irrespective of the data (size ranging from 10 bytes to 10 kb, 50kb 70kb etc) sending across the servers on
I was testing with 5 transactions (with data size of 13 bytes) from one machine (server1) i.e 5 windows of internet explorer. When I clicked on all the five, one after another quickly, I found that 4 transactions got success and one browser went to hang mode.
Second time when I clicked on it, I found that 3 transactions got success, 1 in hang mode and 1 failed.
We traced the exception at the point where it fails. Everytime it fails while reading the response back from the other end through InputStreamBuffer. The block in which it fails is
Please follow the piece of code which i have written
//reading response from the destination decrypt url,
//which is also encrypted and signed
//sending the same to caller of encrypt
String data="";
int end=0;
char c[]=new char[4*1024];
BufferedReader buf=null;
//reading data in a chunks of data     
try
     inr=new InputStreamReader(connection.getInputStream());
     buf=new BufferedReader(inr,12*1024);          
     while ((end=buf.read(c))!=-1)
          data=new StringBuffer(data).append(c,0,end).toString();
catch(OutOfMemoryError e)
     System.out.println("Out of memory errror"+e.getMessage());
     try
          response.sendError(HttpServletResponse.SC_NOT_FOUND);
          return;
     catch(Exception e1)
          return;
catch(Exception e1)
     System.out.println("Failure in reading response"+e1.getMessage());
     try
          response.sendError(HttpServletResponse.SC_NOT_FOUND);
          return;
     catch(Exception e2)
          return;
finally
     try
          if(inr!=null)
               inr.close();
          if(buf!=null)
               buf.close();
          if (connection != null)
               connection.disconnect();     
     catch(Exception e)
          System.out.println("Error in closing connection"+e.getMessage());
Here the connection get disconnected and throws the following exceptions at difterent time of testing in failure case.
1. Failure in reading response JVM_recv in socket input stream read (code=10004)
Error in closing connection Socket closed
2. Null pointer exception.
Could you please tell us what would be the reasons for the above exceptions or failure and how to rectify or handle it.
Thanks & Regards
Gabriel

Answer 1

Can anybody look into it , this very urgent
thanks
Gabriel