/*
* ====================================================================
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*
*/
package org.apache.http.nio.protocol;
import java.io.Closeable;
import java.io.IOException;
import java.net.SocketTimeoutException;
import org.apache.http.ConnectionReuseStrategy;
import org.apache.http.HttpConnection;
import org.apache.http.HttpEntity;
import org.apache.http.HttpEntityEnclosingRequest;
import org.apache.http.HttpException;
import org.apache.http.HttpRequest;
import org.apache.http.HttpResponse;
import org.apache.http.HttpResponseFactory;
import org.apache.http.HttpStatus;
import org.apache.http.HttpVersion;
import org.apache.http.MethodNotSupportedException;
import org.apache.http.ProtocolException;
import org.apache.http.UnsupportedHttpVersionException;
import org.apache.http.annotation.Immutable;
import org.apache.http.concurrent.Cancellable;
import org.apache.http.entity.ContentType;
import org.apache.http.impl.DefaultHttpResponseFactory;
import org.apache.http.nio.ContentDecoder;
import org.apache.http.nio.ContentEncoder;
import org.apache.http.nio.NHttpConnection;
import org.apache.http.nio.NHttpServerConnection;
import org.apache.http.nio.NHttpServerEventHandler;
import org.apache.http.nio.entity.NStringEntity;
import org.apache.http.params.DefaultedHttpParams;
import org.apache.http.params.HttpConnectionParams;
import org.apache.http.params.HttpParams;
import org.apache.http.protocol.BasicHttpContext;
import org.apache.http.protocol.ExecutionContext;
import org.apache.http.protocol.HttpContext;
import org.apache.http.protocol.HttpProcessor;
/**
* <tt>HttpAsyncService</tt> is a fully asynchronous HTTP server side protocol
* handler based on the non-blocking (NIO) I/O model.
* <tt>HttpAsyncServerProtocolHandler</tt> translates individual events fired
* through the {@link NHttpServerEventHandler} interface into logically related
* HTTP message exchanges.
* <p/>
* Upon receiving an incoming request <tt>HttpAsyncService</tt> verifies
* the message for compliance with the server expectations using
* {@link HttpAsyncExpectationVerifier}, if provided, and then
* {@link HttpAsyncRequestHandlerResolver} is used to resolve the request URI
* to a particular {@link HttpAsyncRequestHandler} intended to handle
* the request with the given URI. The protocol handler uses the selected
* {@link HttpAsyncRequestHandler} instance to process the incoming request
* and to generate an outgoing response.
* <p/>
* <tt>HttpAsyncService</tt> relies on {@link HttpProcessor} to generate
* mandatory protocol headers for all outgoing messages and apply common,
* cross-cutting message transformations to all incoming and outgoing messages,
* whereas individual {@link HttpAsyncRequestHandler}s are expected
* to implement application specific content generation and processing.
* <p/>
* Individual {@link HttpAsyncRequestHandler}s do not have to submit a response
* immediately. They can defer transmission of an HTTP response back to
* the client without blocking the I/O thread by delegating the process of
* request handling to another service or a worker thread. HTTP response can
* be submitted as a later a later point of time once response content becomes
* available.
* <p/>
* The following parameters can be used to customize the behavior of this
* class:
* <ul>
* <li>{@link org.apache.http.params.CoreConnectionPNames#SO_TIMEOUT}</li>
* </ul>
*
* @since 4.2
*/
@Immutable // provided injected dependencies are immutable
public class HttpAsyncService implements NHttpServerEventHandler {
static final String HTTP_EXCHANGE_STATE = "http.nio.http-exchange-state";
private final HttpProcessor httpProcessor;
private final ConnectionReuseStrategy connStrategy;
private final HttpResponseFactory responseFactory;
private final HttpAsyncRequestHandlerResolver handlerResolver;
private final HttpAsyncExpectationVerifier expectationVerifier;
private final HttpParams params;
/**
* Creates an instance of <tt>HttpAsyncServerProtocolHandler</tt>.
*
* @param httpProcessor HTTP protocol processor (required).
* @param connStrategy Connection re-use strategy (required).
* @param responseFactory HTTP response factory (required).
* @param handlerResolver Request handler resolver.
* @param expectationVerifier Request expectation verifier (optional).
* @param params HTTP parameters (required).
*/
public HttpAsyncService(
final HttpProcessor httpProcessor,
final ConnectionReuseStrategy connStrategy,
final HttpResponseFactory responseFactory,
final HttpAsyncRequestHandlerResolver handlerResolver,
final HttpAsyncExpectationVerifier expectationVerifier,
final HttpParams params) {
super();
if (httpProcessor == null) {
throw new IllegalArgumentException("HTTP processor may not be null.");
}
if (connStrategy == null) {
throw new IllegalArgumentException("Connection reuse strategy may not be null");
}
if (responseFactory == null) {
throw new IllegalArgumentException("Response factory may not be null");
}
if (params == null) {
throw new IllegalArgumentException("HTTP parameters may not be null");
}
this.httpProcessor = httpProcessor;
this.connStrategy = connStrategy;
this.responseFactory = responseFactory;
this.handlerResolver = handlerResolver;
this.expectationVerifier = expectationVerifier;
this.params = params;
}
/**
* Creates an instance of <tt>HttpAsyncServerProtocolHandler</tt>.
*
* @param httpProcessor HTTP protocol processor (required).
* @param connStrategy Connection re-use strategy (required).
* @param handlerResolver Request handler resolver.
* @param params HTTP parameters (required).
*/
public HttpAsyncService(
final HttpProcessor httpProcessor,
final ConnectionReuseStrategy connStrategy,
final HttpAsyncRequestHandlerResolver handlerResolver,
final HttpParams params) {
this(httpProcessor, connStrategy, new DefaultHttpResponseFactory(),
handlerResolver, null, params);
}
public void connected(final NHttpServerConnection conn) {
State state = new State();
conn.getContext().setAttribute(HTTP_EXCHANGE_STATE, state);
}
public void closed(final NHttpServerConnection conn) {
State state = getState(conn);
if (state != null) {
state.setTerminated();
closeHandlers(state);
Cancellable cancellable = state.getCancellable();
if (cancellable != null) {
cancellable.cancel();
}
state.reset();
}
}
public void exception(
final NHttpServerConnection conn, final Exception cause) {
State state = ensureNotNull(getState(conn));
if (state != null) {
state.setTerminated();
closeHandlers(state, cause);
Cancellable cancellable = state.getCancellable();
if (cancellable != null) {
cancellable.cancel();
}
if (cause instanceof HttpException) {
if (conn.isResponseSubmitted()
|| state.getResponseState().compareTo(MessageState.INIT) > 0) {
// There is not much that we can do if a response
// has already been submitted
closeConnection(conn);
log(cause);
} else {
HttpContext context = state.getContext();
HttpAsyncResponseProducer responseProducer = handleException(
cause, context);
state.setResponseProducer(responseProducer);
try {
HttpResponse response = responseProducer.generateResponse();
state.setResponse(response);
commitFinalResponse(conn, state);
} catch (Exception ex) {
shutdownConnection(conn);
closeHandlers(state);
if (ex instanceof RuntimeException) {
throw (RuntimeException) ex;
} else {
log(ex);
}
}
}
} else {
shutdownConnection(conn);
}
} else {
shutdownConnection(conn);
log(cause);
}
}
public void requestReceived(
final NHttpServerConnection conn) throws IOException, HttpException {
State state = ensureNotNull(getState(conn));
if (state.getResponseState() != MessageState.READY) {
throw new ProtocolException("Out of sequence request message detected (pipelining is not supported)");
}
HttpRequest request = conn.getHttpRequest();
HttpContext context = state.getContext();
request.setParams(new DefaultedHttpParams(request.getParams(), this.params));
context.setAttribute(ExecutionContext.HTTP_REQUEST, request);
context.setAttribute(ExecutionContext.HTTP_CONNECTION, conn);
this.httpProcessor.process(request, context);
state.setRequest(request);
HttpAsyncRequestHandler<Object> requestHandler = getRequestHandler(request);
state.setRequestHandler(requestHandler);
HttpAsyncRequestConsumer<Object> consumer = requestHandler.processRequest(request, context);
state.setRequestConsumer(consumer);
consumer.requestReceived(request);
if (request instanceof HttpEntityEnclosingRequest) {
if (((HttpEntityEnclosingRequest) request).expectContinue()) {
state.setRequestState(MessageState.ACK_EXPECTED);
HttpResponse ack = this.responseFactory.newHttpResponse(HttpVersion.HTTP_1_1,
HttpStatus.SC_CONTINUE, context);
if (this.expectationVerifier != null) {
conn.suspendInput();
HttpAsyncExchange httpex = new Exchange(
request, ack, state, conn);
this.expectationVerifier.verify(httpex, context);
} else {
conn.submitResponse(ack);
state.setRequestState(MessageState.BODY_STREAM);
}
} else {
state.setRequestState(MessageState.BODY_STREAM);
}
} else {
// No request content is expected.
// Process request right away
processRequest(conn, state);
}
}
public void inputReady(
final NHttpServerConnection conn,
final ContentDecoder decoder) throws IOException, HttpException {
State state = ensureNotNull(getState(conn));
HttpAsyncRequestConsumer<?> consumer = ensureNotNull(state.getRequestConsumer());
consumer.consumeContent(decoder, conn);
state.setRequestState(MessageState.BODY_STREAM);
if (decoder.isCompleted()) {
processRequest(conn, state);
}
}
public void responseReady(
final NHttpServerConnection conn) throws IOException, HttpException {
State state = ensureNotNull(getState(conn));
if (state.getResponse() != null) {
return;
}
HttpAsyncResponseProducer responseProducer = state.getResponseProducer();
if (responseProducer == null) {
return;
}
HttpContext context = state.getContext();
HttpResponse response = responseProducer.generateResponse();
int status = response.getStatusLine().getStatusCode();
if (state.getRequestState() == MessageState.ACK_EXPECTED) {
if (status == 100) {
try {
// Make sure 100 response has no entity
response.setEntity(null);
conn.requestInput();
state.setRequestState(MessageState.BODY_STREAM);
conn.submitResponse(response);
responseProducer.responseCompleted(context);
} finally {
state.setResponseProducer(null);
responseProducer.close();
}
} else if (status >= 400) {
conn.resetInput();
state.setRequestState(MessageState.COMPLETED);
state.setResponse(response);
commitFinalResponse(conn, state);
} else {
throw new HttpException("Invalid response: " + response.getStatusLine());
}
} else {
if (status >= 200) {
state.setResponse(response);
commitFinalResponse(conn, state);
} else {
throw new HttpException("Invalid response: " + response.getStatusLine());
}
}
}
public void outputReady(
final NHttpServerConnection conn,
final ContentEncoder encoder) throws IOException {
State state = ensureNotNull(getState(conn));
HttpAsyncResponseProducer responseProducer = state.getResponseProducer();
HttpContext context = state.getContext();
HttpResponse response = state.getResponse();
responseProducer.produceContent(encoder, conn);
state.setResponseState(MessageState.BODY_STREAM);
if (encoder.isCompleted()) {
responseProducer.responseCompleted(context);
if (!this.connStrategy.keepAlive(response, context)) {
conn.close();
} else {
conn.requestInput();
}
closeHandlers(state);
state.reset();
conn.setSocketTimeout(HttpConnectionParams.getSoTimeout(this.params));
}
}
public void endOfInput(final NHttpServerConnection conn) throws IOException {
// Closing connection in an orderly manner and
// waiting for output buffer to get flushed.
// Do not want to wait indefinitely, though, in case
// the opposite end is not reading
if (conn.getSocketTimeout() <= 0) {
conn.setSocketTimeout(1000);
}
conn.close();
}
public void timeout(final NHttpServerConnection conn) throws IOException {
State state = getState(conn);
if (state != null) {
closeHandlers(state, new SocketTimeoutException());
}
if (conn.getStatus() == NHttpConnection.ACTIVE) {
conn.close();
if (conn.getStatus() == NHttpConnection.CLOSING) {
// Give the connection some grace time to
// close itself nicely
conn.setSocketTimeout(250);
}
} else {
conn.shutdown();
}
}
private State getState(final NHttpConnection conn) {
return (State) conn.getContext().getAttribute(HTTP_EXCHANGE_STATE);
}
private State ensureNotNull(final State state) {
if (state == null) {
throw new IllegalStateException("HTTP exchange state is null");
}
return state;
}
private HttpAsyncRequestConsumer<Object> ensureNotNull(final HttpAsyncRequestConsumer<Object> requestConsumer) {
if (requestConsumer == null) {
throw new IllegalStateException("Request consumer is null");
}
return requestConsumer;
}
/**
* This method can be used to log I/O exception thrown while closing {@link Closeable}
* objects (such as {@link HttpConnection}).
*
* @param ex I/O exception thrown by {@link Closeable#close()}
*/
protected void log(final Exception ex) {
}
private void closeConnection(final NHttpConnection conn) {
try {
conn.close();
} catch (IOException ex) {
log(ex);
}
}
private void shutdownConnection(final NHttpConnection conn) {
try {
conn.shutdown();
} catch (IOException ex) {
log(ex);
}
}
private void closeHandlers(final State state, final Exception ex) {
HttpAsyncRequestConsumer<Object> consumer = state.getRequestConsumer();
if (consumer != null) {
try {
consumer.failed(ex);
} finally {
try {
consumer.close();
} catch (IOException ioex) {
log(ioex);
}
}
}
HttpAsyncResponseProducer producer = state.getResponseProducer();
if (producer != null) {
try {
producer.failed(ex);
} finally {
try {
producer.close();
} catch (IOException ioex) {
log(ioex);
}
}
}
}
private void closeHandlers(final State state) {
HttpAsyncRequestConsumer<Object> consumer = state.getRequestConsumer();
if (consumer != null) {
try {
consumer.close();
} catch (IOException ioex) {
log(ioex);
}
}
HttpAsyncResponseProducer producer = state.getResponseProducer();
if (producer != null) {
try {
producer.close();
} catch (IOException ioex) {
log(ioex);
}
}
}
protected HttpAsyncResponseProducer handleException(
final Exception ex, final HttpContext context) {
int code = HttpStatus.SC_INTERNAL_SERVER_ERROR;
if (ex instanceof MethodNotSupportedException) {
code = HttpStatus.SC_NOT_IMPLEMENTED;
} else if (ex instanceof UnsupportedHttpVersionException) {
code = HttpStatus.SC_HTTP_VERSION_NOT_SUPPORTED;
} else if (ex instanceof ProtocolException) {
code = HttpStatus.SC_BAD_REQUEST;
}
String message = ex.getMessage();
if (message == null) {
message = ex.toString();
}
HttpResponse response = this.responseFactory.newHttpResponse(HttpVersion.HTTP_1_1,
code, context);
return new ErrorResponseProducer(response,
new NStringEntity(message, ContentType.DEFAULT_TEXT), false);
}
private boolean canResponseHaveBody(final HttpRequest request, final HttpResponse response) {
if (request != null && "HEAD".equalsIgnoreCase(request.getRequestLine().getMethod())) {
return false;
}
int status = response.getStatusLine().getStatusCode();
return status >= HttpStatus.SC_OK
&& status != HttpStatus.SC_NO_CONTENT
&& status != HttpStatus.SC_NOT_MODIFIED
&& status != HttpStatus.SC_RESET_CONTENT;
}
private void processRequest(
final NHttpServerConnection conn,
final State state) throws HttpException, IOException {
HttpAsyncRequestHandler<Object> handler = state.getRequestHandler();
HttpContext context = state.getContext();
HttpAsyncRequestConsumer<?> consumer = state.getRequestConsumer();
consumer.requestCompleted(context);
state.setRequestState(MessageState.COMPLETED);
state.setResponseState(MessageState.INIT);
Exception exception = consumer.getException();
if (exception != null) {
HttpAsyncResponseProducer responseProducer = handleException(exception, context);
state.setResponseProducer(responseProducer);
conn.requestOutput();
} else {
HttpRequest request = state.getRequest();
Object result = consumer.getResult();
HttpResponse response = this.responseFactory.newHttpResponse(HttpVersion.HTTP_1_1,
HttpStatus.SC_OK, context);
Exchange httpexchange = new Exchange(request, response, state, conn);
try {
handler.handle(result, httpexchange, context);
} catch (HttpException ex) {
HttpAsyncResponseProducer responseProducer = handleException(ex, context);
state.setResponseProducer(responseProducer);
conn.requestOutput();
}
}
}
private void commitFinalResponse(
final NHttpServerConnection conn,
final State state) throws IOException, HttpException {
HttpContext context = state.getContext();
HttpRequest request = state.getRequest();
HttpResponse response = state.getResponse();
response.setParams(new DefaultedHttpParams(response.getParams(), this.params));
context.setAttribute(ExecutionContext.HTTP_RESPONSE, response);
this.httpProcessor.process(response, context);
HttpEntity entity = response.getEntity();
if (entity != null && !canResponseHaveBody(request, response)) {
response.setEntity(null);
entity = null;
}
conn.submitResponse(response);
if (entity == null) {
HttpAsyncResponseProducer responseProducer = state.getResponseProducer();
responseProducer.responseCompleted(context);
if (!this.connStrategy.keepAlive(response, context)) {
conn.close();
} else {
// Ready to process new request
conn.requestInput();
}
closeHandlers(state);
state.reset();
conn.setSocketTimeout(HttpConnectionParams.getSoTimeout(this.params));
} else {
state.setResponseState(MessageState.BODY_STREAM);
}
}
@SuppressWarnings("unchecked")
private HttpAsyncRequestHandler<Object> getRequestHandler(final HttpRequest request) {
HttpAsyncRequestHandler<Object> handler = null;
if (this.handlerResolver != null) {
String requestURI = request.getRequestLine().getUri();
handler = (HttpAsyncRequestHandler<Object>) this.handlerResolver.lookup(requestURI);
}
if (handler == null) {
handler = new NullRequestHandler();
}
return handler;
}
static class State {
private final BasicHttpContext context;
private volatile boolean terminated;
private volatile HttpAsyncRequestHandler<Object> requestHandler;
private volatile MessageState requestState;
private volatile MessageState responseState;
private volatile HttpAsyncRequestConsumer<Object> requestConsumer;
private volatile HttpAsyncResponseProducer responseProducer;
private volatile HttpRequest request;
private volatile HttpResponse response;
private volatile Cancellable cancellable;
State() {
super();
this.context = new BasicHttpContext();
this.requestState = MessageState.READY;
this.responseState = MessageState.READY;
}
public HttpContext getContext() {
return this.context;
}
public boolean isTerminated() {
return this.terminated;
}
public void setTerminated() {
this.terminated = true;
}
public HttpAsyncRequestHandler<Object> getRequestHandler() {
return this.requestHandler;
}
public void setRequestHandler(final HttpAsyncRequestHandler<Object> requestHandler) {
this.requestHandler = requestHandler;
}
public MessageState getRequestState() {
return this.requestState;
}
public void setRequestState(final MessageState state) {
this.requestState = state;
}
public MessageState getResponseState() {
return this.responseState;
}
public void setResponseState(final MessageState state) {
this.responseState = state;
}
public HttpAsyncRequestConsumer<Object> getRequestConsumer() {
return this.requestConsumer;
}
public void setRequestConsumer(final HttpAsyncRequestConsumer<Object> requestConsumer) {
this.requestConsumer = requestConsumer;
}
public HttpAsyncResponseProducer getResponseProducer() {
return this.responseProducer;
}
public void setResponseProducer(final HttpAsyncResponseProducer responseProducer) {
this.responseProducer = responseProducer;
}
public HttpRequest getRequest() {
return this.request;
}
public void setRequest(final HttpRequest request) {
this.request = request;
}
public HttpResponse getResponse() {
return this.response;
}
public void setResponse(final HttpResponse response) {
this.response = response;
}
public Cancellable getCancellable() {
return this.cancellable;
}
public void setCancellable(final Cancellable cancellable) {
this.cancellable = cancellable;
}
public void reset() {
this.context.clear();
this.responseState = MessageState.READY;
this.requestState = MessageState.READY;
this.requestHandler = null;
this.requestConsumer = null;
this.responseProducer = null;
this.request = null;
this.response = null;
this.cancellable = null;
}
@Override
public String toString() {
StringBuilder buf = new StringBuilder();
buf.append("request state: ");
buf.append(this.requestState);
buf.append("; request: ");
if (this.request != null) {
buf.append(this.request.getRequestLine());
}
buf.append("; response state: ");
buf.append(this.responseState);
buf.append("; response: ");
if (this.response != null) {
buf.append(this.response.getStatusLine());
}
buf.append(";");
return buf.toString();
}
}
static class Exchange implements HttpAsyncExchange {
private final HttpRequest request;
private final HttpResponse response;
private final State state;
private final NHttpServerConnection conn;
private volatile boolean completed;
public Exchange(
final HttpRequest request,
final HttpResponse response,
final State state,
final NHttpServerConnection conn) {
super();
this.request = request;
this.response = response;
this.state = state;
this.conn = conn;
}
public HttpRequest getRequest() {
return this.request;
}
public HttpResponse getResponse() {
return this.response;
}
public void setCallback(final Cancellable cancellable) {
synchronized (this) {
if (this.completed) {
throw new IllegalStateException("Response already submitted");
}
if (this.state.isTerminated() && cancellable != null) {
cancellable.cancel();
} else {
this.state.setCancellable(cancellable);
this.conn.requestInput();
}
}
}
public void submitResponse(final HttpAsyncResponseProducer responseProducer) {
if (responseProducer == null) {
throw new IllegalArgumentException("Response producer may not be null");
}
synchronized (this) {
if (this.completed) {
throw new IllegalStateException("Response already submitted");
}
this.completed = true;
if (!this.state.isTerminated()) {
this.state.setResponseProducer(responseProducer);
this.state.setCancellable(null);
this.conn.requestOutput();
} else {
try {
responseProducer.close();
} catch (IOException ex) {
}
}
}
}
public void submitResponse() {
submitResponse(new BasicAsyncResponseProducer(this.response));
}
public boolean isCompleted() {
return this.completed;
}
public void setTimeout(int timeout) {
this.conn.setSocketTimeout(timeout);
}
public int getTimeout() {
return this.conn.getSocketTimeout();
}
}
}