/*
* This file is part of the Wayback archival access software
* (http://archive-access.sourceforge.net/projects/wayback/).
*
* Licensed to the Internet Archive (IA) by one or more individual
* contributors.
*
* The IA 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.
*/
package org.archive.wayback.replay;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import javax.servlet.http.HttpServletResponse;
import org.archive.wayback.ResultURIConverter;
import org.archive.wayback.core.CaptureSearchResult;
import org.archive.wayback.core.Resource;
import org.archive.wayback.exception.BadContentException;
/**
*
*
* @author brad
* @version $Date$, $Revision$
*/
public class HttpHeaderOperation {
public final static String HTTP_LENGTH_HEADER = "Content-Length";
public final static String HTTP_LENGTH_HEADER_UP =
HTTP_LENGTH_HEADER.toUpperCase();
public final static String HTTP_TRANSFER_ENC_HEADER =
"Transfer-Encoding".toUpperCase();
public final static String HTTP_CHUNKED_ENCODING_HEADER =
"chunked".toUpperCase();
public final static String HTTP_CONTENT_ENCODING = "Content-Encoding";
public static final String HTTP_RANGE_HEADER = "Range";
public static final String HTTP_RANGE_HEADER_UP = HTTP_RANGE_HEADER
.toUpperCase();
public static final String HTTP_CONTENT_RANGE_HEADER = "Content-Range";
public static final String HTTP_CONTENT_RANGE_HEADER_UP = HTTP_CONTENT_RANGE_HEADER
.toUpperCase();
/**
* @param resource
* @param httpResponse
* @throws BadContentException
*/
public static void copyHTTPMessageHeader(Resource resource,
HttpServletResponse httpResponse) throws BadContentException {
// set status code from original resource (which will definitely confuse
// many clients...)
int code = resource.getStatusCode();
// Only return legit status codes -- don't return any minus
// codes, etc.
if (code <= HttpServletResponse.SC_CONTINUE) {
throw new BadContentException("Bad status code " + code);
}
httpResponse.setStatus(code);
}
/**
* @param resource
* @param result
* @param uriConverter
* @param filter
* @return A HashMap containing the HTTP headers extracted from the Resource.
*/
public static Map<String,String> processHeaders(Resource resource,
CaptureSearchResult result, ResultURIConverter uriConverter,
HttpHeaderProcessor filter) {
HashMap<String,String> output = new HashMap<String,String>();
// copy all HTTP headers, as-is, sending "" instead of nulls.
Map<String,String> headers = resource.getHttpHeaders();
if (headers != null) {
Iterator<String> itr = headers.keySet().iterator();
while(itr.hasNext()) {
String key = itr.next();
String value = headers.get(key);
value = (value == null) ? "" : value;
filter.filter(output, key, value, uriConverter, result);
}
}
return output;
}
/**
* @param headers
* @param response
*/
public static void sendHeaders(Map<String,String> headers,
HttpServletResponse response) {
Iterator<String> itr = headers.keySet().iterator();
while(itr.hasNext()) {
String key = itr.next();
String value = headers.get(key);
value = (value == null) ? "" : value;
response.setHeader(key,value);
}
}
public static String getContentLength(Map<String,String> headers) {
return getHeaderValue(headers,HTTP_LENGTH_HEADER);
}
public static boolean isChunkEncoded(Map<String,String> headers) {
String enc = getHeaderValue(headers,HTTP_TRANSFER_ENC_HEADER);
if(enc != null) {
return enc.toUpperCase().contains(HTTP_CHUNKED_ENCODING_HEADER);
}
return false;
}
public static String getHeaderValue(Map<String,String> headers, String k) {
String value = null;
Iterator<String> itr = headers.keySet().iterator();
String keyUp = k.toUpperCase();
while(itr.hasNext()) {
String key = itr.next();
if(key != null) {
if(key.toUpperCase().contains(keyUp)) {
value = headers.get(key);
break;
}
}
}
return value;
}
public static boolean removeHeader(Map<String,String> headers, String k) {
Iterator<String> itr = headers.keySet().iterator();
String keyUp = k.toUpperCase();
while(itr.hasNext()) {
String key = itr.next();
if(key != null) {
if (key.toUpperCase().contains(keyUp)) {
itr.remove();
return true;
}
}
}
return false;
}
/**
* Replace header field {@code name} value with {@code value}, or
* add it if {@code headers} does not have {@code name}.
* @param headers header fields
* @param name header field name
* @param value new value for the header field
*/
public static void replaceHeader(Map<String, String> headers, String name, String value) {
removeHeader(headers, name);
headers.put(name, value);
}
/**
* Get {@code Range} header field, and return parsed ranges.
* @param headers header fields.
* @return array of long[2] or {@code null} if {@code Range} header
* field is not present, or invalid.
*/
public static long[][] getRange(Map<String, String> headers) {
String rangeValue = getHeaderValue(headers, HTTP_RANGE_HEADER_UP);
if (rangeValue == null) return null;
rangeValue = rangeValue.trim();
return parseRanges(rangeValue);
}
/**
* Parse {@code Range} header field value.
* Only {@code bytes} unit is supported.
* @param rangeValue {@code Range} header field value.
* @return an array of long[2], or {@code null} if invalid.
*/
public static long[][] parseRanges(String rangeValue) {
if (!rangeValue.startsWith("bytes=")) return null;
int s = "bytes=".length();
int pcomma = rangeValue.indexOf(',', s);
if (pcomma < 0) {
long[] range = parseRange(rangeValue.substring(s));
return range != null ? new long[][] { range } : null;
}
int e = rangeValue.length();
List<long[]> ranges = new ArrayList<long[]>();
while (true) {
long[] range = parseRange(rangeValue.substring(s, pcomma));
// TODO: too strict? fails on double comma.
if (range == null) return null;
ranges.add(range);
if ((s = pcomma + 1) >= e) break;
pcomma = rangeValue.indexOf(',', s);
if (pcomma < 0) pcomma = e;
}
return ranges.toArray(new long[ranges.size()][]);
}
/**
* Parse single byte-range-spec.
* For suffix-byte-range-spec (-N), return [-N, -1].
* For byte-range-spec without last-byte-pos (M-), return [M, -1].
* For full-range-spec (M-N), return [M, N + 1].
* @param rangeValue byte-range-spec
* @return long[2], or {@code null} if invalid
*/
public static long[] parseRange(String rangeValue) {
int phyphen = rangeValue.indexOf('-');
if (phyphen == -1) {
// this is a syntax error.
return null;
}
try {
if (phyphen == 0) {
// -N (suffix-byte-range-spec)
long end = Long.parseLong(rangeValue.substring(1));
if (end <= 0) return null;
return new long[] { -end, -1 };
}
if (phyphen == rangeValue.length() - 1) {
// M- (byte-range-spec without last-byte-pos)
long start = Long.parseLong(rangeValue.substring(0, phyphen));
return new long[] { start, -1 };
}
// M-N (byte-range-spec)
long start = Long.parseLong(rangeValue.substring(0, phyphen));
long end = Long.parseLong(rangeValue.substring(phyphen + 1));
if (start > end) return null;
return new long[] { start, end + 1 };
} catch (NumberFormatException ex) {
return null;
}
}
/**
* Return {@code Content-Range} response header field value.
* @param headers response header fields.
* @return Three element array with <em>first-byte-pos</em>, <em>last-byte-pos + 1</em>
* and <em>instance-length</em>, or {@code null} if {@code value} is syntactically invalid.
*/
public static long[] getContentRange(Map<String, String> headers) {
String value = getHeaderValue(headers, HTTP_CONTENT_RANGE_HEADER_UP);
if (value == null) return null;
return parseContentRange(value.trim());
}
/**
* Parse {@code value} as <em>byte-content-range-spec</em>.
* <em>byte-range-resp-spec</em> is parsed with {@link #parseRange(String)}.
* If <em>byte-range-resp-spec</em> is {@code *}, both <em>first-byte-pos</em> and
* <em>last-byte-pos</em> will be {@code -1}.
* @param value {@code Content-Range} header field value.
* @return Three element array with <em>first-byte-pos</em>, <em>last-byte-pos + 1</em>
* and <em>instance-length</em>, or {@code null} if {@code value} is syntactically invalid.
* @see #parseRange
*/
public static long[] parseContentRange(String value) {
if (!value.startsWith("bytes ")) return null;
int s = "bytes ".length();
while (s < value.length() && value.charAt(s) == ' ')
s++;
int pslash = value.indexOf('/', s);
if (pslash < 0) return null;
final String rangeSpec = value.substring(s, pslash).trim();
long start, stop;
if (rangeSpec.equals("*"))
start = stop = -1;
else {
long[] range = parseRange(rangeSpec);
if (range == null) return null;
if (range[0] < 0 || range[1] < 0) return null;
start = range[0];
stop = range[1];
}
final String instanceLength = value.substring(pslash + 1).trim();
long length;
if (instanceLength.equals("*"))
length = -1;
else {
try {
length = Long.parseLong(instanceLength);
} catch (NumberFormatException ex) {
return null;
}
}
return new long[] { start, stop, length };
}
}