/*
* ====================================================================
* 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.impl;
import java.io.IOException;
import java.net.SocketTimeoutException;
import org.apache.http.HttpClientConnection;
import org.apache.http.HttpConnectionMetrics;
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.annotation.NotThreadSafe;
import org.apache.http.entity.ContentLengthStrategy;
import org.apache.http.impl.entity.EntityDeserializer;
import org.apache.http.impl.entity.EntitySerializer;
import org.apache.http.impl.entity.LaxContentLengthStrategy;
import org.apache.http.impl.entity.StrictContentLengthStrategy;
import org.apache.http.impl.io.HttpRequestWriter;
import org.apache.http.impl.io.HttpResponseParser;
import org.apache.http.io.EofSensor;
import org.apache.http.io.HttpMessageParser;
import org.apache.http.io.HttpMessageWriter;
import org.apache.http.io.HttpTransportMetrics;
import org.apache.http.io.SessionInputBuffer;
import org.apache.http.io.SessionOutputBuffer;
import org.apache.http.message.LineFormatter;
import org.apache.http.message.LineParser;
import org.apache.http.params.HttpParams;
/**
* Abstract client-side HTTP connection capable of transmitting and receiving
* data using arbitrary {@link SessionInputBuffer} and
* {@link SessionOutputBuffer} implementations.
* <p>
* The following parameters can be used to customize the behavior of this
* class:
* <ul>
* <li>{@link org.apache.http.params.CoreProtocolPNames#STRICT_TRANSFER_ENCODING}</li>
* <li>{@link org.apache.http.params.CoreConnectionPNames#MAX_HEADER_COUNT}</li>
* </ul>
*
* @since 4.0
*/
@NotThreadSafe
public abstract class AbstractHttpClientConnection implements HttpClientConnection {
private final EntitySerializer entityserializer;
private final EntityDeserializer entitydeserializer;
private SessionInputBuffer inbuffer = null;
private SessionOutputBuffer outbuffer = null;
private EofSensor eofSensor = null;
private HttpMessageParser<HttpResponse> responseParser = null;
private HttpMessageWriter<HttpRequest> requestWriter = null;
private HttpConnectionMetricsImpl metrics = null;
/**
* Creates an instance of this class.
* <p>
* This constructor will invoke {@link #createEntityDeserializer()}
* and {@link #createEntitySerializer()} methods in order to initialize
* HTTP entity serializer and deserializer implementations for this
* connection.
*/
public AbstractHttpClientConnection() {
super();
this.entityserializer = createEntitySerializer();
this.entitydeserializer = createEntityDeserializer();
}
/**
* Asserts if the connection is open.
*
* @throws IllegalStateException if the connection is not open.
*/
protected abstract void assertOpen() throws IllegalStateException;
/**
* Creates an instance of {@link EntityDeserializer} with the
* {@link LaxContentLengthStrategy} implementation to be used for
* de-serializing entities received over this connection.
* <p>
* This method can be overridden in a super class in order to create
* instances of {@link EntityDeserializer} using a custom
* {@link ContentLengthStrategy}.
*
* @return HTTP entity deserializer
*/
protected EntityDeserializer createEntityDeserializer() {
return new EntityDeserializer(new LaxContentLengthStrategy());
}
/**
* Creates an instance of {@link EntitySerializer} with the
* {@link StrictContentLengthStrategy} implementation to be used for
* serializing HTTP entities sent over this connection.
* <p>
* This method can be overridden in a super class in order to create
* instances of {@link EntitySerializer} using a custom
* {@link ContentLengthStrategy}.
*
* @return HTTP entity serialzier.
*/
protected EntitySerializer createEntitySerializer() {
return new EntitySerializer(new StrictContentLengthStrategy());
}
/**
* Creates an instance of {@link DefaultHttpResponseFactory} to be used
* for creating {@link HttpResponse} objects received by over this
* connection.
* <p>
* This method can be overridden in a super class in order to provide
* a different implementation of the {@link HttpResponseFactory} interface.
*
* @return HTTP response factory.
*/
protected HttpResponseFactory createHttpResponseFactory() {
return new DefaultHttpResponseFactory();
}
/**
* Creates an instance of {@link HttpMessageParser} to be used for parsing
* HTTP responses received over this connection.
* <p>
* This method can be overridden in a super class in order to provide
* a different implementation of the {@link HttpMessageParser} interface or
* to pass a different implementation of {@link LineParser} to the
* the default implementation {@link HttpResponseParser}.
*
* @param buffer the session input buffer.
* @param responseFactory the HTTP response factory.
* @param params HTTP parameters.
* @return HTTP message parser.
*/
protected HttpMessageParser<HttpResponse> createResponseParser(
final SessionInputBuffer buffer,
final HttpResponseFactory responseFactory,
final HttpParams params) {
return new HttpResponseParser(buffer, null, responseFactory, params);
}
/**
* Creates an instance of {@link HttpMessageWriter} to be used for
* writing out HTTP requests sent over this connection.
* <p>
* This method can be overridden in a super class in order to provide
* a different implementation of the {@link HttpMessageWriter} interface or
* to pass a different implementation of {@link LineFormatter} to the
* the default implementation {@link HttpRequestWriter}.
*
* @param buffer the session output buffer
* @param params HTTP parameters
* @return HTTP message writer
*/
protected HttpMessageWriter<HttpRequest> createRequestWriter(
final SessionOutputBuffer buffer,
final HttpParams params) {
return new HttpRequestWriter(buffer, null, params);
}
/**
* @since 4.1
*/
protected HttpConnectionMetricsImpl createConnectionMetrics(
final HttpTransportMetrics inTransportMetric,
final HttpTransportMetrics outTransportMetric) {
return new HttpConnectionMetricsImpl(inTransportMetric, outTransportMetric);
}
/**
* Initializes this connection object with {@link SessionInputBuffer} and
* {@link SessionOutputBuffer} instances to be used for sending and
* receiving data. These session buffers can be bound to any arbitrary
* physical output medium.
* <p>
* This method will invoke {@link #createHttpResponseFactory()},
* {@link #createRequestWriter(SessionOutputBuffer, HttpParams)}
* and {@link #createResponseParser(SessionInputBuffer, HttpResponseFactory, HttpParams)}
* methods to initialize HTTP request writer and response parser for this
* connection.
*
* @param inbuffer the session input buffer.
* @param outbuffer the session output buffer.
* @param params HTTP parameters.
*/
protected void init(
final SessionInputBuffer inbuffer,
final SessionOutputBuffer outbuffer,
final HttpParams params) {
if (inbuffer == null) {
throw new IllegalArgumentException("Input session buffer may not be null");
}
if (outbuffer == null) {
throw new IllegalArgumentException("Output session buffer may not be null");
}
this.inbuffer = inbuffer;
this.outbuffer = outbuffer;
if (inbuffer instanceof EofSensor) {
this.eofSensor = (EofSensor) inbuffer;
}
this.responseParser = createResponseParser(
inbuffer,
createHttpResponseFactory(),
params);
this.requestWriter = createRequestWriter(
outbuffer, params);
this.metrics = createConnectionMetrics(
inbuffer.getMetrics(),
outbuffer.getMetrics());
}
public boolean isResponseAvailable(int timeout) throws IOException {
assertOpen();
return this.inbuffer.isDataAvailable(timeout);
}
public void sendRequestHeader(final HttpRequest request)
throws HttpException, IOException {
if (request == null) {
throw new IllegalArgumentException("HTTP request may not be null");
}
assertOpen();
this.requestWriter.write(request);
this.metrics.incrementRequestCount();
}
public void sendRequestEntity(final HttpEntityEnclosingRequest request)
throws HttpException, IOException {
if (request == null) {
throw new IllegalArgumentException("HTTP request may not be null");
}
assertOpen();
if (request.getEntity() == null) {
return;
}
this.entityserializer.serialize(
this.outbuffer,
request,
request.getEntity());
}
protected void doFlush() throws IOException {
this.outbuffer.flush();
}
public void flush() throws IOException {
assertOpen();
doFlush();
}
public HttpResponse receiveResponseHeader()
throws HttpException, IOException {
assertOpen();
HttpResponse response = this.responseParser.parse();
if (response.getStatusLine().getStatusCode() >= 200) {
this.metrics.incrementResponseCount();
}
return response;
}
public void receiveResponseEntity(final HttpResponse response)
throws HttpException, IOException {
if (response == null) {
throw new IllegalArgumentException("HTTP response may not be null");
}
assertOpen();
HttpEntity entity = this.entitydeserializer.deserialize(this.inbuffer, response);
response.setEntity(entity);
}
protected boolean isEof() {
return this.eofSensor != null && this.eofSensor.isEof();
}
public boolean isStale() {
if (!isOpen()) {
return true;
}
if (isEof()) {
return true;
}
try {
this.inbuffer.isDataAvailable(1);
return isEof();
} catch (SocketTimeoutException ex) {
return false;
} catch (IOException ex) {
return true;
}
}
public HttpConnectionMetrics getMetrics() {
return this.metrics;
}
}