/*
* Copyright (C) 2014 The Android Open Source Project
*
* Licensed 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.
*/
package com.google.android.exoplayer.upstream;
import com.google.android.exoplayer.C;
import com.google.android.exoplayer.util.Assertions;
import com.google.android.exoplayer.util.Predicate;
import com.google.android.exoplayer.util.Util;
import android.text.TextUtils;
import android.util.Log;
import java.io.EOFException;
import java.io.IOException;
import java.io.InputStream;
import java.io.InterruptedIOException;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.NoRouteToHostException;
import java.net.ProtocolException;
import java.net.URL;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.concurrent.atomic.AtomicReference;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
/**
* A {@link HttpDataSource} that uses Android's {@link HttpURLConnection}.
* <p>
* By default this implementation will not follow cross-protocol redirects (i.e. redirects from
* HTTP to HTTPS or vice versa). Cross-protocol redirects can be enabled by using the
* {@link #DefaultHttpDataSource(String, Predicate, TransferListener, int, int, boolean)}
* constructor and passing {@code true} as the final argument.
*/
public class DefaultHttpDataSource implements HttpDataSource {
/**
* The default connection timeout, in milliseconds.
*/
public static final int DEFAULT_CONNECT_TIMEOUT_MILLIS = 8 * 1000;
/**
* The default read timeout, in milliseconds.
*/
public static final int DEFAULT_READ_TIMEOUT_MILLIS = 8 * 1000;
private static final int MAX_REDIRECTS = 20; // Same limit as okhttp.
private static final String TAG = "DefaultHttpDataSource";
private static final Pattern CONTENT_RANGE_HEADER =
Pattern.compile("^bytes (\\d+)-(\\d+)/(\\d+)$");
private static final AtomicReference<byte[]> skipBufferReference = new AtomicReference<>();
private final boolean allowCrossProtocolRedirects;
private final int connectTimeoutMillis;
private final int readTimeoutMillis;
private final String userAgent;
private final Predicate<String> contentTypePredicate;
private final HashMap<String, String> requestProperties;
private final TransferListener listener;
private DataSpec dataSpec;
private HttpURLConnection connection;
private InputStream inputStream;
private boolean opened;
private long bytesToSkip;
private long bytesToRead;
private long bytesSkipped;
private long bytesRead;
/**
* @param userAgent The User-Agent string that should be used.
* @param contentTypePredicate An optional {@link Predicate}. If a content type is
* rejected by the predicate then a {@link HttpDataSource.InvalidContentTypeException} is
* thrown from {@link #open(DataSpec)}.
*/
public DefaultHttpDataSource(String userAgent, Predicate<String> contentTypePredicate) {
this(userAgent, contentTypePredicate, null);
}
/**
* @param userAgent The User-Agent string that should be used.
* @param contentTypePredicate An optional {@link Predicate}. If a content type is
* rejected by the predicate then a {@link HttpDataSource.InvalidContentTypeException} is
* thrown from {@link #open(DataSpec)}.
* @param listener An optional listener.
*/
public DefaultHttpDataSource(String userAgent, Predicate<String> contentTypePredicate,
TransferListener listener) {
this(userAgent, contentTypePredicate, listener, DEFAULT_CONNECT_TIMEOUT_MILLIS,
DEFAULT_READ_TIMEOUT_MILLIS);
}
/**
* @param userAgent The User-Agent string that should be used.
* @param contentTypePredicate An optional {@link Predicate}. If a content type is
* rejected by the predicate then a {@link HttpDataSource.InvalidContentTypeException} is
* thrown from {@link #open(DataSpec)}.
* @param listener An optional listener.
* @param connectTimeoutMillis The connection timeout, in milliseconds. A timeout of zero is
* interpreted as an infinite timeout.
* @param readTimeoutMillis The read timeout, in milliseconds. A timeout of zero is interpreted
* as an infinite timeout.
*/
public DefaultHttpDataSource(String userAgent, Predicate<String> contentTypePredicate,
TransferListener listener, int connectTimeoutMillis, int readTimeoutMillis) {
this(userAgent, contentTypePredicate, listener, connectTimeoutMillis, readTimeoutMillis, false);
}
/**
* @param userAgent The User-Agent string that should be used.
* @param contentTypePredicate An optional {@link Predicate}. If a content type is
* rejected by the predicate then a {@link HttpDataSource.InvalidContentTypeException} is
* thrown from {@link #open(DataSpec)}.
* @param listener An optional listener.
* @param connectTimeoutMillis The connection timeout, in milliseconds. A timeout of zero is
* interpreted as an infinite timeout. Pass {@link #DEFAULT_CONNECT_TIMEOUT_MILLIS} to use
* the default value.
* @param readTimeoutMillis The read timeout, in milliseconds. A timeout of zero is interpreted
* as an infinite timeout. Pass {@link #DEFAULT_READ_TIMEOUT_MILLIS} to use the default value.
* @param allowCrossProtocolRedirects Whether cross-protocol redirects (i.e. redirects from HTTP
* to HTTPS and vice versa) are enabled.
*/
public DefaultHttpDataSource(String userAgent, Predicate<String> contentTypePredicate,
TransferListener listener, int connectTimeoutMillis, int readTimeoutMillis,
boolean allowCrossProtocolRedirects) {
this.userAgent = Assertions.checkNotEmpty(userAgent);
this.contentTypePredicate = contentTypePredicate;
this.listener = listener;
this.requestProperties = new HashMap<>();
this.connectTimeoutMillis = connectTimeoutMillis;
this.readTimeoutMillis = readTimeoutMillis;
this.allowCrossProtocolRedirects = allowCrossProtocolRedirects;
}
@Override
public String getUri() {
return connection == null ? null : connection.getURL().toString();
}
@Override
public Map<String, List<String>> getResponseHeaders() {
return connection == null ? null : connection.getHeaderFields();
}
@Override
public void setRequestProperty(String name, String value) {
Assertions.checkNotNull(name);
Assertions.checkNotNull(value);
synchronized (requestProperties) {
requestProperties.put(name, value);
}
}
@Override
public void clearRequestProperty(String name) {
Assertions.checkNotNull(name);
synchronized (requestProperties) {
requestProperties.remove(name);
}
}
@Override
public void clearAllRequestProperties() {
synchronized (requestProperties) {
requestProperties.clear();
}
}
@Override
public long open(DataSpec dataSpec) throws HttpDataSourceException {
this.dataSpec = dataSpec;
this.bytesRead = 0;
this.bytesSkipped = 0;
try {
connection = makeConnection(dataSpec);
} catch (IOException e) {
throw new HttpDataSourceException("Unable to connect to " + dataSpec.uri.toString(), e,
dataSpec);
}
int responseCode;
try {
responseCode = connection.getResponseCode();
} catch (IOException e) {
closeConnectionQuietly();
throw new HttpDataSourceException("Unable to connect to " + dataSpec.uri.toString(), e,
dataSpec);
}
// Check for a valid response code.
if (responseCode < 200 || responseCode > 299) {
Map<String, List<String>> headers = connection.getHeaderFields();
closeConnectionQuietly();
throw new InvalidResponseCodeException(responseCode, headers, dataSpec);
}
// Check for a valid content type.
String contentType = connection.getContentType();
if (contentTypePredicate != null && !contentTypePredicate.evaluate(contentType)) {
closeConnectionQuietly();
throw new InvalidContentTypeException(contentType, dataSpec);
}
// If we requested a range starting from a non-zero position and received a 200 rather than a
// 206, then the server does not support partial requests. We'll need to manually skip to the
// requested position.
bytesToSkip = responseCode == 200 && dataSpec.position != 0 ? dataSpec.position : 0;
// Determine the length of the data to be read, after skipping.
if ((dataSpec.flags & DataSpec.FLAG_ALLOW_GZIP) == 0) {
long contentLength = getContentLength(connection);
bytesToRead = dataSpec.length != C.LENGTH_UNBOUNDED ? dataSpec.length
: contentLength != C.LENGTH_UNBOUNDED ? contentLength - bytesToSkip
: C.LENGTH_UNBOUNDED;
} else {
// Gzip is enabled. If the server opts to use gzip then the content length in the response
// will be that of the compressed data, which isn't what we want. Furthermore, there isn't a
// reliable way to determine whether the gzip was used or not. Always use the dataSpec length
// in this case.
bytesToRead = dataSpec.length;
}
try {
inputStream = connection.getInputStream();
} catch (IOException e) {
closeConnectionQuietly();
throw new HttpDataSourceException(e, dataSpec);
}
opened = true;
if (listener != null) {
listener.onTransferStart();
}
return bytesToRead;
}
@Override
public int read(byte[] buffer, int offset, int readLength) throws HttpDataSourceException {
try {
skipInternal();
return readInternal(buffer, offset, readLength);
} catch (IOException e) {
throw new HttpDataSourceException(e, dataSpec);
}
}
@Override
public void close() throws HttpDataSourceException {
try {
if (inputStream != null) {
Util.maybeTerminateInputStream(connection, bytesRemaining());
try {
inputStream.close();
} catch (IOException e) {
throw new HttpDataSourceException(e, dataSpec);
}
}
} finally {
inputStream = null;
closeConnectionQuietly();
if (opened) {
opened = false;
if (listener != null) {
listener.onTransferEnd();
}
}
}
}
/**
* Returns the current connection, or null if the source is not currently opened.
*
* @return The current open connection, or null.
*/
protected final HttpURLConnection getConnection() {
return connection;
}
/**
* Returns the number of bytes that have been skipped since the most recent call to
* {@link #open(DataSpec)}.
*
* @return The number of bytes skipped.
*/
protected final long bytesSkipped() {
return bytesSkipped;
}
/**
* Returns the number of bytes that have been read since the most recent call to
* {@link #open(DataSpec)}.
*
* @return The number of bytes read.
*/
protected final long bytesRead() {
return bytesRead;
}
/**
* Returns the number of bytes that are still to be read for the current {@link DataSpec}.
* <p>
* If the total length of the data being read is known, then this length minus {@code bytesRead()}
* is returned. If the total length is unknown, {@link C#LENGTH_UNBOUNDED} is returned.
*
* @return The remaining length, or {@link C#LENGTH_UNBOUNDED}.
*/
protected final long bytesRemaining() {
return bytesToRead == C.LENGTH_UNBOUNDED ? bytesToRead : bytesToRead - bytesRead;
}
/**
* Establishes a connection, following redirects to do so where permitted.
*/
private HttpURLConnection makeConnection(DataSpec dataSpec) throws IOException {
URL url = new URL(dataSpec.uri.toString());
byte[] postBody = dataSpec.postBody;
long position = dataSpec.position;
long length = dataSpec.length;
boolean allowGzip = (dataSpec.flags & DataSpec.FLAG_ALLOW_GZIP) != 0;
if (!allowCrossProtocolRedirects) {
// HttpURLConnection disallows cross-protocol redirects, but otherwise performs redirection
// automatically. This is the behavior we want, so use it.
HttpURLConnection connection = makeConnection(
url, postBody, position, length, allowGzip, true /* followRedirects */);
return connection;
}
// We need to handle redirects ourselves to allow cross-protocol redirects.
int redirectCount = 0;
while (redirectCount++ <= MAX_REDIRECTS) {
HttpURLConnection connection = makeConnection(
url, postBody, position, length, allowGzip, false /* followRedirects */);
int responseCode = connection.getResponseCode();
if (responseCode == HttpURLConnection.HTTP_MULT_CHOICE
|| responseCode == HttpURLConnection.HTTP_MOVED_PERM
|| responseCode == HttpURLConnection.HTTP_MOVED_TEMP
|| responseCode == HttpURLConnection.HTTP_SEE_OTHER
|| (postBody == null
&& (responseCode == 307 /* HTTP_TEMP_REDIRECT */
|| responseCode == 308 /* HTTP_PERM_REDIRECT */))) {
// For 300, 301, 302, and 303 POST requests follow the redirect and are transformed into
// GET requests. For 307 and 308 POST requests are not redirected.
postBody = null;
String location = connection.getHeaderField("Location");
connection.disconnect();
url = handleRedirect(url, location);
} else {
return connection;
}
}
// If we get here we've been redirected more times than are permitted.
throw new NoRouteToHostException("Too many redirects: " + redirectCount);
}
/**
* Configures a connection and opens it.
*
* @param url The url to connect to.
* @param postBody The body data for a POST request.
* @param position The byte offset of the requested data.
* @param length The length of the requested data, or {@link C#LENGTH_UNBOUNDED}.
* @param allowGzip Whether to allow the use of gzip.
* @param followRedirects Whether to follow redirects.
*/
private HttpURLConnection makeConnection(URL url, byte[] postBody, long position,
long length, boolean allowGzip, boolean followRedirects) throws IOException {
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setConnectTimeout(connectTimeoutMillis);
connection.setReadTimeout(readTimeoutMillis);
synchronized (requestProperties) {
for (Map.Entry<String, String> property : requestProperties.entrySet()) {
connection.setRequestProperty(property.getKey(), property.getValue());
}
}
if (!(position == 0 && length == C.LENGTH_UNBOUNDED)) {
String rangeRequest = "bytes=" + position + "-";
if (length != C.LENGTH_UNBOUNDED) {
rangeRequest += (position + length - 1);
}
connection.setRequestProperty("Range", rangeRequest);
}
connection.setRequestProperty("User-Agent", userAgent);
if (!allowGzip) {
connection.setRequestProperty("Accept-Encoding", "identity");
}
connection.setInstanceFollowRedirects(followRedirects);
connection.setDoOutput(postBody != null);
if (postBody != null) {
connection.setFixedLengthStreamingMode(postBody.length);
connection.connect();
OutputStream os = connection.getOutputStream();
os.write(postBody);
os.close();
} else {
connection.connect();
}
return connection;
}
/**
* Handles a redirect.
*
* @param originalUrl The original URL.
* @param location The Location header in the response.
* @return The next URL.
* @throws IOException If redirection isn't possible.
*/
private static URL handleRedirect(URL originalUrl, String location) throws IOException {
if (location == null) {
throw new ProtocolException("Null location redirect");
}
// Form the new url.
URL url = new URL(originalUrl, location);
// Check that the protocol of the new url is supported.
String protocol = url.getProtocol();
if (!"https".equals(protocol) && !"http".equals(protocol)) {
throw new ProtocolException("Unsupported protocol redirect: " + protocol);
}
// Currently this method is only called if allowCrossProtocolRedirects is true, and so the code
// below isn't required. If we ever decide to handle redirects ourselves when cross-protocol
// redirects are disabled, we'll need to uncomment this block of code.
// if (!allowCrossProtocolRedirects && !protocol.equals(originalUrl.getProtocol())) {
// throw new ProtocolException("Disallowed cross-protocol redirect ("
// + originalUrl.getProtocol() + " to " + protocol + ")");
// }
return url;
}
/**
* Attempts to extract the length of the content from the response headers of an open connection.
*
* @param connection The open connection.
* @return The extracted length, or {@link C#LENGTH_UNBOUNDED}.
*/
private static long getContentLength(HttpURLConnection connection) {
long contentLength = C.LENGTH_UNBOUNDED;
String contentLengthHeader = connection.getHeaderField("Content-Length");
if (!TextUtils.isEmpty(contentLengthHeader)) {
try {
contentLength = Long.parseLong(contentLengthHeader);
} catch (NumberFormatException e) {
Log.e(TAG, "Unexpected Content-Length [" + contentLengthHeader + "]");
}
}
String contentRangeHeader = connection.getHeaderField("Content-Range");
if (!TextUtils.isEmpty(contentRangeHeader)) {
Matcher matcher = CONTENT_RANGE_HEADER.matcher(contentRangeHeader);
if (matcher.find()) {
try {
long contentLengthFromRange =
Long.parseLong(matcher.group(2)) - Long.parseLong(matcher.group(1)) + 1;
if (contentLength < 0) {
// Some proxy servers strip the Content-Length header. Fall back to the length
// calculated here in this case.
contentLength = contentLengthFromRange;
} else if (contentLength != contentLengthFromRange) {
// If there is a discrepancy between the Content-Length and Content-Range headers,
// assume the one with the larger value is correct. We have seen cases where carrier
// change one of them to reduce the size of a request, but it is unlikely anybody would
// increase it.
Log.w(TAG, "Inconsistent headers [" + contentLengthHeader + "] [" + contentRangeHeader
+ "]");
contentLength = Math.max(contentLength, contentLengthFromRange);
}
} catch (NumberFormatException e) {
Log.e(TAG, "Unexpected Content-Range [" + contentRangeHeader + "]");
}
}
}
return contentLength;
}
/**
* Skips any bytes that need skipping. Else does nothing.
* <p>
* This implementation is based roughly on {@code libcore.io.Streams.skipByReading()}.
*
* @throws InterruptedIOException If the thread is interrupted during the operation.
* @throws EOFException If the end of the input stream is reached before the bytes are skipped.
*/
private void skipInternal() throws IOException {
if (bytesSkipped == bytesToSkip) {
return;
}
// Acquire the shared skip buffer.
byte[] skipBuffer = skipBufferReference.getAndSet(null);
if (skipBuffer == null) {
skipBuffer = new byte[4096];
}
while (bytesSkipped != bytesToSkip) {
int readLength = (int) Math.min(bytesToSkip - bytesSkipped, skipBuffer.length);
int read = inputStream.read(skipBuffer, 0, readLength);
if (Thread.interrupted()) {
throw new InterruptedIOException();
}
if (read == -1) {
throw new EOFException();
}
bytesSkipped += read;
if (listener != null) {
listener.onBytesTransferred(read);
}
}
// Release the shared skip buffer.
skipBufferReference.set(skipBuffer);
}
/**
* Reads up to {@code length} bytes of data and stores them into {@code buffer}, starting at
* index {@code offset}.
* <p>
* This method blocks until at least one byte of data can be read, the end of the opened range is
* detected, or an exception is thrown.
*
* @param buffer The buffer into which the read data should be stored.
* @param offset The start offset into {@code buffer} at which data should be written.
* @param readLength The maximum number of bytes to read.
* @return The number of bytes read, or {@link C#RESULT_END_OF_INPUT} if the end of the opened
* range is reached.
* @throws IOException If an error occurs reading from the source.
*/
private int readInternal(byte[] buffer, int offset, int readLength) throws IOException {
readLength = bytesToRead == C.LENGTH_UNBOUNDED ? readLength
: (int) Math.min(readLength, bytesToRead - bytesRead);
if (readLength == 0) {
// We've read all of the requested data.
return C.RESULT_END_OF_INPUT;
}
int read = inputStream.read(buffer, offset, readLength);
if (read == -1) {
if (bytesToRead != C.LENGTH_UNBOUNDED && bytesToRead != bytesRead) {
// The server closed the connection having not sent sufficient data.
throw new EOFException();
}
return C.RESULT_END_OF_INPUT;
}
bytesRead += read;
if (listener != null) {
listener.onBytesTransferred(read);
}
return read;
}
/**
* Closes the current connection quietly, if there is one.
*/
private void closeConnectionQuietly() {
if (connection != null) {
try {
connection.disconnect();
} catch (Exception e) {
Log.e(TAG, "Unexpected error while disconnecting", e);
}
connection = null;
}
}
}