org.jdrupes.httpcodec.protocols.http.client.HttpRequestEncoder Maven / Gradle / Ivy

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HTTP coders and decoders for non-blocking I/O
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/*
 * This file is part of the JDrupes non-blocking HTTP Codec
 * Copyright (C) 2016, 2017  Michael N. Lipp
 *
 * This program is free software; you can redistribute it and/or modify it 
 * under the terms of the GNU Lesser General Public License as published
 * by the Free Software Foundation; either version 3 of the License, or 
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but 
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public 
 * License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License along 
 * with this program; if not, see .
 */

package org.jdrupes.httpcodec.protocols.http.client;

import java.io.IOException;
import java.io.Writer;
import java.net.URI;
import java.nio.Buffer;
import java.util.Optional;
import java.util.ServiceLoader;
import java.util.stream.StreamSupport;

import org.jdrupes.httpcodec.plugin.UpgradeProvider;
import org.jdrupes.httpcodec.protocols.http.HttpConstants.HttpProtocol;
import org.jdrupes.httpcodec.protocols.http.HttpEncoder;
import org.jdrupes.httpcodec.protocols.http.HttpField;
import org.jdrupes.httpcodec.protocols.http.HttpRequest;
import org.jdrupes.httpcodec.protocols.http.HttpResponse;
import org.jdrupes.httpcodec.types.Converters;
import org.jdrupes.httpcodec.types.StringList;

/**
 * An encoder for HTTP requests that accepts a header and optional
 * payload data end encodes it into a sequence of
 * {@link Buffer}s.
 * 
 * ![HttpRequestEncoder](httprequestencoder.svg)
 * 
 * @startuml httprequestencoder.svg
 * class HttpRequestEncoder {
 * 	+HttpRequestEncoder(Engine engine)
 * }
 * 
 * class HttpEncoder {
 * }
 * 
 * HttpEncoder <|-- HttpRequestEncoder : <>  HttpRequest>
 *
 */
public class HttpRequestEncoder 
	extends HttpEncoder {

	private static Result.Factory resultFactory = new Result.Factory() {
	};
	
	/* (non-Javadoc)
	 * @see org.jdrupes.httpcodec.Encoder#encoding()
	 */
	@Override
	public Class encoding() {
		return HttpRequest.class;
	}

	/* (non-Javadoc)
	 * @see org.jdrupes.httpcodec.protocols.http.HttpEncoder#resultFactory()
	 */
	@Override
	protected Result.Factory resultFactory() {
		return resultFactory;
	}

	/* (non-Javadoc)
	 * @see HttpEncoder#encode(HttpMessageHeader)
	 */
	@Override
	public void encode(HttpRequest messageHeader) {
		if (messageHeader.protocol().equals(HttpProtocol.HTTP_1_1)) {
			// Make sure we have a Host field, RFC 7230 5.4
			if (!messageHeader.findStringValue(HttpField.HOST).isPresent()) {
				URI reqUri = messageHeader.requestUri();
				messageHeader.setField(HttpField.HOST, reqUri.getHost()
						+ (reqUri.getPort() < 0 ? "" 
								: (":" + reqUri.getPort())));
			}
		}
		messageHeader.findField(HttpField.UPGRADE, Converters.STRING_LIST)
			.ifPresent(field -> prepareUpgrade(field, messageHeader));
		super.encode(messageHeader);
	}

	private void prepareUpgrade(
			HttpField field, HttpRequest request) {
		if (field.value().isEmpty()) {
			throw new IllegalArgumentException(
					"Upgrade header field must have a value.");
		}
		String protocol = field.value().get(0);
		// Load every time to support dynamic deployment of additional
		// services in an OSGi environment.
		Optional protocolPlugin = StreamSupport.stream(
				ServiceLoader.load(UpgradeProvider.class).spliterator(), false)
				.filter(p -> p.supportsProtocol(protocol))
				.findFirst();
		if (!protocolPlugin.isPresent()) {
			// Not supported, maybe transparent to HTTP 
			return;
		}
		protocolPlugin.get().augmentInitialRequest(request);
	}
	
	/* (non-Javadoc)
	 * @see Encoder#startMessage(MessageHeader, java.io.Writer)
	 */
	@Override
	protected void startMessage(HttpRequest messageHeader, Writer writer)
	        throws IOException {
		writer.write(messageHeader.method());
		writer.write(" ");
		writer.write(messageHeader.requestUri().toString());
		writer.write(" ");
		writer.write(messageHeader.protocol().toString());
		writer.write("\r\n");
	}
	
	/**
	 * Results from {@link HttpRequestEncoder} add no additional
	 * information to 
	 * {@link org.jdrupes.httpcodec.protocols.http.HttpEncoder.Result}. This
	 * class just provides a factory for creating concrete results.
	 */
	public static class Result extends HttpEncoder.Result {

		protected Result(boolean overflow, boolean underflow,
		        boolean closeConnection) {
			super(overflow, underflow, closeConnection);
		}
	
		/**
		 * A concrete factory for creating new Results.
		 */
		protected static class Factory extends HttpEncoder.Result.Factory {
		}		
	}
}