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/*
* $HeadURL: http://svn.apache.org/repos/asf/httpcomponents/httpcore/trunk/module-main/src/main/java/org/apache/http/impl/io/SocketInputBuffer.java $
* $Revision: 560358 $
* $Date: 2007-07-27 12:30:42 -0700 (Fri, 27 Jul 2007) $
*
* ====================================================================
* 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.io;
import java.io.IOException;
import java.io.InterruptedIOException;
import java.net.Socket;
import java.net.SocketTimeoutException;
import org.apache.http.params.HttpParams;
/**
* {@link Socket} bound session input buffer.
*
* @author <a href="mailto:oleg at ural.ru">Oleg Kalnichevski</a>
*
* @version $Revision: 560358 $
*
* @since 4.0
*/
public class SocketInputBuffer extends AbstractSessionInputBuffer {
static private final Class SOCKET_TIMEOUT_CLASS = SocketTimeoutExceptionClass();
/**
* Returns <code>SocketTimeoutExceptionClass<code> or <code>null</code> if the class
* does not exist.
*
* @return <code>SocketTimeoutExceptionClass<code>, or <code>null</code> if unavailable.
*/
static private Class SocketTimeoutExceptionClass() {
try {
return Class.forName("java.net.SocketTimeoutException");
} catch (ClassNotFoundException e) {
return null;
}
}
private static boolean isSocketTimeoutException(final InterruptedIOException e) {
if (SOCKET_TIMEOUT_CLASS != null) {
return SOCKET_TIMEOUT_CLASS.isInstance(e);
} else {
return true;
}
}
private final Socket socket;
public SocketInputBuffer(
final Socket socket,
int buffersize,
final HttpParams params) throws IOException {
super();
if (socket == null) {
throw new IllegalArgumentException("Socket may not be null");
}
this.socket = socket;
if (buffersize < 0) {
buffersize = socket.getReceiveBufferSize();
}
if (buffersize < 1024) {
buffersize = 1024;
}
init(socket.getInputStream(), buffersize, params);
}
public boolean isDataAvailable(int timeout) throws IOException {
boolean result = hasBufferedData();
if (!result) {
int oldtimeout = this.socket.getSoTimeout();
try {
this.socket.setSoTimeout(timeout);
fillBuffer();
result = hasBufferedData();
} catch (InterruptedIOException e) {
if (!isSocketTimeoutException(e)) {
throw e;
}
} finally {
socket.setSoTimeout(oldtimeout);
}
}
return result;
}
// BEGIN android-added
/**
* Returns true if the connection is probably functional. It's insufficient
* to rely on isDataAvailable() returning normally; that approach cannot
* distinguish between an exhausted stream and a stream with zero bytes
* buffered.
*
* @hide
*/
public boolean isStale() throws IOException {
if (hasBufferedData()) {
return false;
}
int oldTimeout = this.socket.getSoTimeout();
try {
this.socket.setSoTimeout(1);
return fillBuffer() == -1;
} catch (SocketTimeoutException e) {
return false; // the connection is not stale; hooray
} catch (IOException e) {
return true; // the connection is stale, the read or soTimeout failed.
} finally {
this.socket.setSoTimeout(oldTimeout);
}
}
// END android-added
}
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