how to read the request in chunks in httpcomponents NIO server? - apache-httpcomponents

Question

I am using httpcomponenets nio server to handle post request.
Below is the sample code. It gets the complete data in byte array using EntityUtils.toByteArray(). This fails if the requester sends a large file.
I couldnt figure out how to read the data in the request in chunks.
HttpEntity.getContent().read() always returns null
public static void main(String[] args) throws Exception {
int port = 8280;
// Create HTTP protocol processing chain
HttpProcessor httpproc = HttpProcessorBuilder.create()
.add(new ResponseDate())
.add(new ResponseServer("Test/1.1"))
.add(new ResponseContent())
.add(new ResponseConnControl()).build();
// Create request handler registry
UriHttpAsyncRequestHandlerMapper reqistry = new UriHttpAsyncRequestHandlerMapper();
// Register the default handler for all URIs
reqistry.register("/test*", new RequestHandler());
// Create server-side HTTP protocol handler
HttpAsyncService protocolHandler = new HttpAsyncService(httpproc, reqistry) {
#Override
public void connected(final NHttpServerConnection conn) {
System.out.println(conn + ": connection open");
super.connected(conn);
}
#Override
public void closed(final NHttpServerConnection conn) {
System.out.println(conn + ": connection closed");
super.closed(conn);
}
};
// Create HTTP connection factory
NHttpConnectionFactory<DefaultNHttpServerConnection> connFactory;
connFactory = new DefaultNHttpServerConnectionFactory(
ConnectionConfig.DEFAULT);
// Create server-side I/O event dispatch
IOEventDispatch ioEventDispatch = new DefaultHttpServerIODispatch(protocolHandler, connFactory);
// Set I/O reactor defaults
IOReactorConfig config = IOReactorConfig.custom()
.setIoThreadCount(1)
.setSoTimeout(3000)
.setConnectTimeout(3000)
.build();
// Create server-side I/O reactor
ListeningIOReactor ioReactor = new DefaultListeningIOReactor(config);
try {
// Listen of the given port
ioReactor.listen(new InetSocketAddress(port));
// Ready to go!
ioReactor.execute(ioEventDispatch);
} catch (InterruptedIOException ex) {
System.err.println("Interrupted");
} catch (IOException e) {
System.err.println("I/O error: " + e.getMessage());
}
System.out.println("Shutdown");
}
public static class RequestHandler implements HttpAsyncRequestHandler<HttpRequest> {
public void handleInternal(HttpRequest httpRequest, HttpResponse httpResponse, HttpContext httpContext) throws HttpException, IOException {
HttpEntity entity = null;
if (httpRequest instanceof HttpEntityEnclosingRequest)
entity = ((HttpEntityEnclosingRequest)httpRequest).getEntity();
byte[] data;
if (entity == null) {
data = new byte [0];
} else {
data = EntityUtils.toByteArray(entity);
}
System.out.println(new String(data));
httpResponse.setEntity(new StringEntity("success response"));
}
#Override public HttpAsyncRequestConsumer<HttpRequest> processRequest(HttpRequest request, HttpContext context) throws HttpException, IOException {
return new BasicAsyncRequestConsumer();
}
#Override
public void handle(HttpRequest request, HttpAsyncExchange httpExchange, HttpContext context) throws HttpException, IOException {
HttpResponse response = httpExchange.getResponse();
handleInternal(request, response, context);
httpExchange.submitResponse(new BasicAsyncResponseProducer(response));
}
}

Answer 1

Please consider implementing a custom AbstractAsyncRequestConsumer instead of BasicAsyncRequestConsumer if you want to have full control over request processing.
You might use these classes as a starting point [1][2]. Please note these are response consumers though one can use the same approach to create custom request consumers:
[1] http://hc.apache.org/httpcomponents-asyncclient-4.1.x/httpasyncclient/xref/org/apache/http/nio/client/methods/AsyncCharConsumer.html
[2] http://hc.apache.org/httpcomponents-asyncclient-4.1.x/httpasyncclient/xref/org/apache/http/nio/client/methods/AsyncByteConsumer.html