Java tutorial
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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.nio; import java.io.IOException; 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.impl.nio.codecs.DefaultHttpRequestWriter; import org.apache.http.impl.nio.codecs.DefaultHttpResponseParser; import org.apache.http.nio.NHttpClientConnection; import org.apache.http.nio.NHttpClientIOTarget; import org.apache.http.nio.NHttpClientHandler; import org.apache.http.nio.NHttpMessageParser; import org.apache.http.nio.NHttpMessageWriter; import org.apache.http.nio.reactor.EventMask; import org.apache.http.nio.reactor.IOSession; import org.apache.http.nio.reactor.SessionInputBuffer; import org.apache.http.nio.reactor.SessionOutputBuffer; import org.apache.http.nio.util.ByteBufferAllocator; import org.apache.http.params.HttpParams; /** * Default implementation of the {@link NHttpClientConnection} interface. * <p> * The following parameters can be used to customize the behavior of this * class: * <ul> * <li>{@link org.apache.http.params.CoreProtocolPNames#HTTP_ELEMENT_CHARSET}</li> * <li>{@link org.apache.http.params.CoreConnectionPNames#SOCKET_BUFFER_SIZE}</li> * <li>{@link org.apache.http.params.CoreConnectionPNames#MAX_HEADER_COUNT}</li> * <li>{@link org.apache.http.params.CoreConnectionPNames#MAX_LINE_LENGTH}</li> * </ul> * * @since 4.0 */ public class DefaultNHttpClientConnection extends NHttpConnectionBase implements NHttpClientIOTarget { protected final NHttpMessageParser<HttpResponse> responseParser; protected final NHttpMessageWriter<HttpRequest> requestWriter; /** * Creates a new instance of this class given the underlying I/O session. * * @param session the underlying I/O session. * @param responseFactory HTTP response factory. * @param allocator byte buffer allocator. * @param params HTTP parameters. */ public DefaultNHttpClientConnection(final IOSession session, final HttpResponseFactory responseFactory, final ByteBufferAllocator allocator, final HttpParams params) { super(session, allocator, params); if (responseFactory == null) { throw new IllegalArgumentException("Response factory may not be null"); } this.responseParser = createResponseParser(this.inbuf, responseFactory, params); this.requestWriter = createRequestWriter(this.outbuf, params); this.hasBufferedInput = false; this.hasBufferedOutput = false; this.session.setBufferStatus(this); } /** * Creates an instance of {@link NHttpMessageParser} to be used * by this connection for parsing incoming {@link HttpResponse} messages. * <p> * This method can be overridden in a super class in order to provide * a different implementation of the {@link NHttpMessageParser} interface. * * @return HTTP response parser. */ protected NHttpMessageParser<HttpResponse> createResponseParser(final SessionInputBuffer buffer, final HttpResponseFactory responseFactory, final HttpParams params) { // override in derived class to specify a line parser return new DefaultHttpResponseParser(buffer, null, responseFactory, params); } /** * Creates an instance of {@link NHttpMessageWriter} to be used * by this connection for writing out outgoing {@link HttpRequest} messages. * <p> * This method can be overridden by a super class in order to provide * a different implementation of the {@link NHttpMessageWriter} interface. * * @return HTTP response parser. */ protected NHttpMessageWriter<HttpRequest> createRequestWriter(final SessionOutputBuffer buffer, final HttpParams params) { // override in derived class to specify a line formatter return new DefaultHttpRequestWriter(buffer, null, params); } public void resetInput() { this.response = null; this.contentDecoder = null; this.responseParser.reset(); } public void resetOutput() { this.request = null; this.contentEncoder = null; this.requestWriter.reset(); } public void consumeInput(final NHttpClientHandler handler) { if (this.status != ACTIVE) { this.session.clearEvent(EventMask.READ); return; } try { if (this.response == null) { int bytesRead; do { bytesRead = this.responseParser.fillBuffer(this.session.channel()); if (bytesRead > 0) { this.inTransportMetrics.incrementBytesTransferred(bytesRead); } this.response = this.responseParser.parse(); } while (bytesRead > 0 && this.response == null); if (this.response != null) { if (this.response.getStatusLine().getStatusCode() >= 200) { HttpEntity entity = prepareDecoder(this.response); this.response.setEntity(entity); this.connMetrics.incrementResponseCount(); } handler.responseReceived(this); if (this.contentDecoder == null) { resetInput(); } } if (bytesRead == -1) { close(); } } if (this.contentDecoder != null) { handler.inputReady(this, this.contentDecoder); if (this.contentDecoder.isCompleted()) { // Response entity received // Ready to receive a new response resetInput(); } } } catch (IOException ex) { handler.exception(this, ex); } catch (HttpException ex) { resetInput(); handler.exception(this, ex); } finally { // Finally set buffered input flag this.hasBufferedInput = this.inbuf.hasData(); } } public void produceOutput(final NHttpClientHandler handler) { try { if (this.outbuf.hasData()) { int bytesWritten = this.outbuf.flush(this.session.channel()); if (bytesWritten > 0) { this.outTransportMetrics.incrementBytesTransferred(bytesWritten); } } if (!this.outbuf.hasData()) { if (this.status == CLOSING) { this.session.close(); this.status = CLOSED; resetOutput(); return; } else { if (this.contentEncoder != null) { handler.outputReady(this, this.contentEncoder); if (this.contentEncoder.isCompleted()) { resetOutput(); } } } if (this.contentEncoder == null && !this.outbuf.hasData()) { if (this.status == CLOSING) { this.session.close(); this.status = CLOSED; } if (this.status != CLOSED) { this.session.clearEvent(EventMask.WRITE); handler.requestReady(this); } } } } catch (IOException ex) { handler.exception(this, ex); } finally { // Finally set buffered output flag this.hasBufferedOutput = this.outbuf.hasData(); } } public void submitRequest(final HttpRequest request) throws IOException, HttpException { if (request == null) { throw new IllegalArgumentException("HTTP request may not be null"); } assertNotClosed(); if (this.request != null) { throw new HttpException("Request already submitted"); } this.requestWriter.write(request); this.hasBufferedOutput = this.outbuf.hasData(); if (request instanceof HttpEntityEnclosingRequest && ((HttpEntityEnclosingRequest) request).getEntity() != null) { prepareEncoder(request); this.request = request; } this.connMetrics.incrementRequestCount(); this.session.setEvent(EventMask.WRITE); } public boolean isRequestSubmitted() { return this.request != null; } }