michael@0: /*
michael@0:  * ====================================================================
michael@0:  * Licensed to the Apache Software Foundation (ASF) under one
michael@0:  * or more contributor license agreements.  See the NOTICE file
michael@0:  * distributed with this work for additional information
michael@0:  * regarding copyright ownership.  The ASF licenses this file
michael@0:  * to you under the Apache License, Version 2.0 (the
michael@0:  * "License"); you may not use this file except in compliance
michael@0:  * with the License.  You may obtain a copy of the License at
michael@0:  *
michael@0:  *   http://www.apache.org/licenses/LICENSE-2.0
michael@0:  *
michael@0:  * Unless required by applicable law or agreed to in writing,
michael@0:  * software distributed under the License is distributed on an
michael@0:  * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
michael@0:  * KIND, either express or implied.  See the License for the
michael@0:  * specific language governing permissions and limitations
michael@0:  * under the License.
michael@0:  * ====================================================================
michael@0:  *
michael@0:  * This software consists of voluntary contributions made by many
michael@0:  * individuals on behalf of the Apache Software Foundation.  For more
michael@0:  * information on the Apache Software Foundation, please see
michael@0:  * <http://www.apache.org/>.
michael@0:  *
michael@0:  */
michael@0: 
michael@0: package ch.boye.httpclientandroidlib.impl;
michael@0: 
michael@0: import java.io.IOException;
michael@0: 
michael@0: import ch.boye.httpclientandroidlib.HttpClientConnection;
michael@0: import ch.boye.httpclientandroidlib.HttpConnectionMetrics;
michael@0: import ch.boye.httpclientandroidlib.HttpEntity;
michael@0: import ch.boye.httpclientandroidlib.HttpEntityEnclosingRequest;
michael@0: import ch.boye.httpclientandroidlib.HttpException;
michael@0: import ch.boye.httpclientandroidlib.HttpRequest;
michael@0: import ch.boye.httpclientandroidlib.HttpResponse;
michael@0: import ch.boye.httpclientandroidlib.HttpResponseFactory;
michael@0: import ch.boye.httpclientandroidlib.entity.ContentLengthStrategy;
michael@0: import ch.boye.httpclientandroidlib.impl.entity.EntityDeserializer;
michael@0: import ch.boye.httpclientandroidlib.impl.entity.EntitySerializer;
michael@0: import ch.boye.httpclientandroidlib.impl.entity.LaxContentLengthStrategy;
michael@0: import ch.boye.httpclientandroidlib.impl.entity.StrictContentLengthStrategy;
michael@0: import ch.boye.httpclientandroidlib.impl.io.HttpRequestWriter;
michael@0: import ch.boye.httpclientandroidlib.impl.io.HttpResponseParser;
michael@0: import ch.boye.httpclientandroidlib.io.EofSensor;
michael@0: import ch.boye.httpclientandroidlib.io.HttpMessageParser;
michael@0: import ch.boye.httpclientandroidlib.io.HttpMessageWriter;
michael@0: import ch.boye.httpclientandroidlib.io.HttpTransportMetrics;
michael@0: import ch.boye.httpclientandroidlib.io.SessionInputBuffer;
michael@0: import ch.boye.httpclientandroidlib.io.SessionOutputBuffer;
michael@0: import ch.boye.httpclientandroidlib.message.LineFormatter;
michael@0: import ch.boye.httpclientandroidlib.message.LineParser;
michael@0: import ch.boye.httpclientandroidlib.params.HttpParams;
michael@0: 
michael@0: /**
michael@0:  * Abstract client-side HTTP connection capable of transmitting and receiving
michael@0:  * data using arbitrary {@link SessionInputBuffer} and
michael@0:  * {@link SessionOutputBuffer} implementations.
michael@0:  * <p>
michael@0:  * The following parameters can be used to customize the behavior of this
michael@0:  * class:
michael@0:  * <ul>
michael@0:  *  <li>{@link ch.boye.httpclientandroidlib.params.CoreProtocolPNames#STRICT_TRANSFER_ENCODING}</li>
michael@0:  *  <li>{@link ch.boye.httpclientandroidlib.params.CoreConnectionPNames#MAX_HEADER_COUNT}</li>
michael@0:  * </ul>
michael@0:  *
michael@0:  * @since 4.0
michael@0:  */
michael@0: public abstract class AbstractHttpClientConnection implements HttpClientConnection {
michael@0: 
michael@0:     private final EntitySerializer entityserializer;
michael@0:     private final EntityDeserializer entitydeserializer;
michael@0: 
michael@0:     private SessionInputBuffer inbuffer = null;
michael@0:     private SessionOutputBuffer outbuffer = null;
michael@0:     private EofSensor eofSensor = null;
michael@0:     private HttpMessageParser responseParser = null;
michael@0:     private HttpMessageWriter requestWriter = null;
michael@0:     private HttpConnectionMetricsImpl metrics = null;
michael@0: 
michael@0:     /**
michael@0:      * Creates an instance of this class.
michael@0:      * <p>
michael@0:      * This constructor will invoke {@link #createEntityDeserializer()}
michael@0:      * and {@link #createEntitySerializer()} methods in order to initialize
michael@0:      * HTTP entity serializer and deserializer implementations for this
michael@0:      * connection.
michael@0:      */
michael@0:     public AbstractHttpClientConnection() {
michael@0:         super();
michael@0:         this.entityserializer = createEntitySerializer();
michael@0:         this.entitydeserializer = createEntityDeserializer();
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Asserts if the connection is open.
michael@0:      *
michael@0:      * @throws IllegalStateException if the connection is not open.
michael@0:      */
michael@0:     protected abstract void assertOpen() throws IllegalStateException;
michael@0: 
michael@0:     /**
michael@0:      * Creates an instance of {@link EntityDeserializer} with the
michael@0:      * {@link LaxContentLengthStrategy} implementation to be used for
michael@0:      * de-serializing entities received over this connection.
michael@0:      * <p>
michael@0:      * This method can be overridden in a super class in order to create
michael@0:      * instances of {@link EntityDeserializer} using a custom
michael@0:      * {@link ContentLengthStrategy}.
michael@0:      *
michael@0:      * @return HTTP entity deserializer
michael@0:      */
michael@0:     protected EntityDeserializer createEntityDeserializer() {
michael@0:         return new EntityDeserializer(new LaxContentLengthStrategy());
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Creates an instance of {@link EntitySerializer} with the
michael@0:      * {@link StrictContentLengthStrategy} implementation to be used for
michael@0:      * serializing HTTP entities sent over this connection.
michael@0:      * <p>
michael@0:      * This method can be overridden in a super class in order to create
michael@0:      * instances of {@link EntitySerializer} using a custom
michael@0:      * {@link ContentLengthStrategy}.
michael@0:      *
michael@0:      * @return HTTP entity serialzier.
michael@0:      */
michael@0:     protected EntitySerializer createEntitySerializer() {
michael@0:         return new EntitySerializer(new StrictContentLengthStrategy());
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Creates an instance of {@link DefaultHttpResponseFactory} to be used
michael@0:      * for creating {@link HttpResponse} objects received by over this
michael@0:      * connection.
michael@0:      * <p>
michael@0:      * This method can be overridden in a super class in order to provide
michael@0:      * a different implementation of the {@link HttpResponseFactory} interface.
michael@0:      *
michael@0:      * @return HTTP response factory.
michael@0:      */
michael@0:     protected HttpResponseFactory createHttpResponseFactory() {
michael@0:         return new DefaultHttpResponseFactory();
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Creates an instance of {@link HttpMessageParser} to be used for parsing
michael@0:      * HTTP responses received over this connection.
michael@0:      * <p>
michael@0:      * This method can be overridden in a super class in order to provide
michael@0:      * a different implementation of the {@link HttpMessageParser} interface or
michael@0:      * to pass a different implementation of {@link LineParser} to the
michael@0:      * the default implementation {@link HttpResponseParser}.
michael@0:      *
michael@0:      * @param buffer the session input buffer.
michael@0:      * @param responseFactory the HTTP response factory.
michael@0:      * @param params HTTP parameters.
michael@0:      * @return HTTP message parser.
michael@0:      */
michael@0:     protected HttpMessageParser createResponseParser(
michael@0:             final SessionInputBuffer buffer,
michael@0:             final HttpResponseFactory responseFactory,
michael@0:             final HttpParams params) {
michael@0:         return new HttpResponseParser(buffer, null, responseFactory, params);
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Creates an instance of {@link HttpMessageWriter} to be used for
michael@0:      * writing out HTTP requests sent over this connection.
michael@0:      * <p>
michael@0:      * This method can be overridden in a super class in order to provide
michael@0:      * a different implementation of the {@link HttpMessageWriter} interface or
michael@0:      * to pass a different implementation of {@link LineFormatter} to the
michael@0:      * the default implementation {@link HttpRequestWriter}.
michael@0:      *
michael@0:      * @param buffer the session output buffer
michael@0:      * @param params HTTP parameters
michael@0:      * @return HTTP message writer
michael@0:      */
michael@0:     protected HttpMessageWriter createRequestWriter(
michael@0:             final SessionOutputBuffer buffer,
michael@0:             final HttpParams params) {
michael@0:         return new HttpRequestWriter(buffer, null, params);
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * @since 4.1
michael@0:      */
michael@0:     protected HttpConnectionMetricsImpl createConnectionMetrics(
michael@0:             final HttpTransportMetrics inTransportMetric,
michael@0:             final HttpTransportMetrics outTransportMetric) {
michael@0:         return new HttpConnectionMetricsImpl(inTransportMetric, outTransportMetric);
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Initializes this connection object with {@link SessionInputBuffer} and
michael@0:      * {@link SessionOutputBuffer} instances to be used for sending and
michael@0:      * receiving data. These session buffers can be bound to any arbitrary
michael@0:      * physical output medium.
michael@0:      * <p>
michael@0:      * This method will invoke {@link #createHttpResponseFactory()},
michael@0:      * {@link #createRequestWriter(SessionOutputBuffer, HttpParams)}
michael@0:      * and {@link #createResponseParser(SessionInputBuffer, HttpResponseFactory, HttpParams)}
michael@0:      * methods to initialize HTTP request writer and response parser for this
michael@0:      * connection.
michael@0:      *
michael@0:      * @param inbuffer the session input buffer.
michael@0:      * @param outbuffer the session output buffer.
michael@0:      * @param params HTTP parameters.
michael@0:      */
michael@0:     protected void init(
michael@0:             final SessionInputBuffer inbuffer,
michael@0:             final SessionOutputBuffer outbuffer,
michael@0:             final HttpParams params) {
michael@0:         if (inbuffer == null) {
michael@0:             throw new IllegalArgumentException("Input session buffer may not be null");
michael@0:         }
michael@0:         if (outbuffer == null) {
michael@0:             throw new IllegalArgumentException("Output session buffer may not be null");
michael@0:         }
michael@0:         this.inbuffer = inbuffer;
michael@0:         this.outbuffer = outbuffer;
michael@0:         if (inbuffer instanceof EofSensor) {
michael@0:             this.eofSensor = (EofSensor) inbuffer;
michael@0:         }
michael@0:         this.responseParser = createResponseParser(
michael@0:                 inbuffer,
michael@0:                 createHttpResponseFactory(),
michael@0:                 params);
michael@0:         this.requestWriter = createRequestWriter(
michael@0:                 outbuffer, params);
michael@0:         this.metrics = createConnectionMetrics(
michael@0:                 inbuffer.getMetrics(),
michael@0:                 outbuffer.getMetrics());
michael@0:     }
michael@0: 
michael@0:     public boolean isResponseAvailable(int timeout) throws IOException {
michael@0:         assertOpen();
michael@0:         return this.inbuffer.isDataAvailable(timeout);
michael@0:     }
michael@0: 
michael@0:     public void sendRequestHeader(final HttpRequest request)
michael@0:             throws HttpException, IOException {
michael@0:         if (request == null) {
michael@0:             throw new IllegalArgumentException("HTTP request may not be null");
michael@0:         }
michael@0:         assertOpen();
michael@0:         this.requestWriter.write(request);
michael@0:         this.metrics.incrementRequestCount();
michael@0:     }
michael@0: 
michael@0:     public void sendRequestEntity(final HttpEntityEnclosingRequest request)
michael@0:             throws HttpException, IOException {
michael@0:         if (request == null) {
michael@0:             throw new IllegalArgumentException("HTTP request may not be null");
michael@0:         }
michael@0:         assertOpen();
michael@0:         if (request.getEntity() == null) {
michael@0:             return;
michael@0:         }
michael@0:         this.entityserializer.serialize(
michael@0:                 this.outbuffer,
michael@0:                 request,
michael@0:                 request.getEntity());
michael@0:     }
michael@0: 
michael@0:     protected void doFlush() throws IOException {
michael@0:         this.outbuffer.flush();
michael@0:     }
michael@0: 
michael@0:     public void flush() throws IOException {
michael@0:         assertOpen();
michael@0:         doFlush();
michael@0:     }
michael@0: 
michael@0:     public HttpResponse receiveResponseHeader()
michael@0:             throws HttpException, IOException {
michael@0:         assertOpen();
michael@0:         HttpResponse response = (HttpResponse) this.responseParser.parse();
michael@0:         if (response.getStatusLine().getStatusCode() >= 200) {
michael@0:             this.metrics.incrementResponseCount();
michael@0:         }
michael@0:         return response;
michael@0:     }
michael@0: 
michael@0:     public void receiveResponseEntity(final HttpResponse response)
michael@0:             throws HttpException, IOException {
michael@0:         if (response == null) {
michael@0:             throw new IllegalArgumentException("HTTP response may not be null");
michael@0:         }
michael@0:         assertOpen();
michael@0:         HttpEntity entity = this.entitydeserializer.deserialize(this.inbuffer, response);
michael@0:         response.setEntity(entity);
michael@0:     }
michael@0: 
michael@0:     protected boolean isEof() {
michael@0:         return this.eofSensor != null && this.eofSensor.isEof();
michael@0:     }
michael@0: 
michael@0:     public boolean isStale() {
michael@0:         if (!isOpen()) {
michael@0:             return true;
michael@0:         }
michael@0:         if (isEof()) {
michael@0:             return true;
michael@0:         }
michael@0:         try {
michael@0:             this.inbuffer.isDataAvailable(1);
michael@0:             return isEof();
michael@0:         } catch (IOException ex) {
michael@0:             return true;
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     public HttpConnectionMetrics getMetrics() {
michael@0:         return this.metrics;
michael@0:     }
michael@0: 
michael@0: }