ServletInputStream ? ? ?

[[Jwas J]]

Hello

Can any one tell me Whats the use of request.getInputStream() ?
I know that it retrieves the body of the request as binary data using a
ServletInputStream. In practical where is it used ?

I tried to use that but server is hanging (throwing ). I dont know why

This is the code i have used

ServletInputStream in = request.getInputStream();
int ch =0;
while ((ch = in.read()) != -1)
        System.out.print((char)ch);


I got the the exception

java.io.InterruptedIOException: Read timed out
                at java.net.SocketInputStream.socketRead(Native Method)
                at java.net.SocketInputStream.read(SocketInputStream.java:86)

Please advice

Regards
Jwas