/*
* ====================================================================
* 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.apach3.http.impl.client.cache;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import org.apach3.http.Header;
import org.apach3.http.HeaderElement;
import org.apach3.http.HttpEntity;
import org.apach3.http.HttpEntityEnclosingRequest;
import org.apach3.http.HttpRequest;
import org.apach3.http.HttpResponse;
import org.apach3.http.HttpStatus;
import org.apach3.http.HttpVersion;
import org.apach3.http.ProtocolVersion;
import org.apach3.http.annotation.Immutable;
import org.apach3.http.client.ClientProtocolException;
import org.apach3.http.client.cache.HeaderConstants;
import org.apach3.http.impl.client.RequestWrapper;
import org.apach3.http.impl.cookie.DateParseException;
import org.apach3.http.impl.cookie.DateUtils;
import org.apach3.http.message.BasicHeader;
import org.apach3.http.protocol.HTTP;
import org.apach3.http.util.EntityUtils;
/**
* @since 4.1
*/
@Immutable
class ResponseProtocolCompliance {
private static final String UNEXPECTED_100_CONTINUE = "The incoming request did not contain a "
+ "100-continue header, but the response was a Status 100, continue.";
private static final String UNEXPECTED_PARTIAL_CONTENT = "partial content was returned for a request that did not ask for it";
/**
* When we get a response from a down stream server (Origin Server)
* we attempt to see if it is HTTP 1.1 Compliant and if not, attempt to
* make it so.
*
* @param request The {@link HttpRequest} that generated an origin hit and response
* @param response The {@link HttpResponse} from the origin server
* @throws IOException Bad things happened
*/
public void ensureProtocolCompliance(HttpRequest request, HttpResponse response)
throws IOException {
if (backendResponseMustNotHaveBody(request, response)) {
consumeBody(response);
response.setEntity(null);
}
requestDidNotExpect100ContinueButResponseIsOne(request, response);
transferEncodingIsNotReturnedTo1_0Client(request, response);
ensurePartialContentIsNotSentToAClientThatDidNotRequestIt(request, response);
ensure200ForOPTIONSRequestWithNoBodyHasContentLengthZero(request, response);
ensure206ContainsDateHeader(response);
ensure304DoesNotContainExtraEntityHeaders(response);
identityIsNotUsedInContentEncoding(response);
warningsWithNonMatchingWarnDatesAreRemoved(response);
}
private void consumeBody(HttpResponse response) throws IOException {
HttpEntity body = response.getEntity();
if (body != null) EntityUtils.consume(body);
}
private void warningsWithNonMatchingWarnDatesAreRemoved(
HttpResponse response) {
Date responseDate = null;
try {
responseDate = DateUtils.parseDate(response.getFirstHeader(HTTP.DATE_HEADER).getValue());
} catch (DateParseException e) {
//Empty On Purpose
}
if (responseDate == null) return;
Header[] warningHeaders = response.getHeaders(HeaderConstants.WARNING);
if (warningHeaders == null || warningHeaders.length == 0) return;
List<Header> newWarningHeaders = new ArrayList<Header>();
boolean modified = false;
for(Header h : warningHeaders) {
for(WarningValue wv : WarningValue.getWarningValues(h)) {
Date warnDate = wv.getWarnDate();
if (warnDate == null || warnDate.equals(responseDate)) {
newWarningHeaders.add(new BasicHeader(HeaderConstants.WARNING,wv.toString()));
} else {
modified = true;
}
}
}
if (modified) {
response.removeHeaders(HeaderConstants.WARNING);
for(Header h : newWarningHeaders) {
response.addHeader(h);
}
}
}
private void identityIsNotUsedInContentEncoding(HttpResponse response) {
Header[] hdrs = response.getHeaders(HTTP.CONTENT_ENCODING);
if (hdrs == null || hdrs.length == 0) return;
List<Header> newHeaders = new ArrayList<Header>();
boolean modified = false;
for (Header h : hdrs) {
StringBuilder buf = new StringBuilder();
boolean first = true;
for (HeaderElement elt : h.getElements()) {
if ("identity".equalsIgnoreCase(elt.getName())) {
modified = true;
} else {
if (!first) buf.append(",");
buf.append(elt.toString());
first = false;
}
}
String newHeaderValue = buf.toString();
if (!"".equals(newHeaderValue)) {
newHeaders.add(new BasicHeader(HTTP.CONTENT_ENCODING, newHeaderValue));
}
}
if (!modified) return;
response.removeHeaders(HTTP.CONTENT_ENCODING);
for (Header h : newHeaders) {
response.addHeader(h);
}
}
private void ensure206ContainsDateHeader(HttpResponse response) {
if (response.getFirstHeader(HTTP.DATE_HEADER) == null) {
response.addHeader(HTTP.DATE_HEADER, DateUtils.formatDate(new Date()));
}
}
private void ensurePartialContentIsNotSentToAClientThatDidNotRequestIt(HttpRequest request,
HttpResponse response) throws IOException {
if (request.getFirstHeader(HeaderConstants.RANGE) != null
|| response.getStatusLine().getStatusCode() != HttpStatus.SC_PARTIAL_CONTENT)
return;
consumeBody(response);
throw new ClientProtocolException(UNEXPECTED_PARTIAL_CONTENT);
}
private void ensure200ForOPTIONSRequestWithNoBodyHasContentLengthZero(HttpRequest request,
HttpResponse response) {
if (!request.getRequestLine().getMethod().equalsIgnoreCase(HeaderConstants.OPTIONS_METHOD)) {
return;
}
if (response.getStatusLine().getStatusCode() != HttpStatus.SC_OK) {
return;
}
if (response.getFirstHeader(HTTP.CONTENT_LEN) == null) {
response.addHeader(HTTP.CONTENT_LEN, "0");
}
}
private void ensure304DoesNotContainExtraEntityHeaders(HttpResponse response) {
String[] disallowedEntityHeaders = { HeaderConstants.ALLOW, HTTP.CONTENT_ENCODING,
"Content-Language", HTTP.CONTENT_LEN, "Content-MD5",
"Content-Range", HTTP.CONTENT_TYPE, HeaderConstants.LAST_MODIFIED
};
if (response.getStatusLine().getStatusCode() == HttpStatus.SC_NOT_MODIFIED) {
for(String hdr : disallowedEntityHeaders) {
response.removeHeaders(hdr);
}
}
}
private boolean backendResponseMustNotHaveBody(HttpRequest request, HttpResponse backendResponse) {
return HeaderConstants.HEAD_METHOD.equals(request.getRequestLine().getMethod())
|| backendResponse.getStatusLine().getStatusCode() == HttpStatus.SC_NO_CONTENT
|| backendResponse.getStatusLine().getStatusCode() == HttpStatus.SC_RESET_CONTENT
|| backendResponse.getStatusLine().getStatusCode() == HttpStatus.SC_NOT_MODIFIED;
}
private void requestDidNotExpect100ContinueButResponseIsOne(HttpRequest request,
HttpResponse response) throws IOException {
if (response.getStatusLine().getStatusCode() != HttpStatus.SC_CONTINUE) {
return;
}
HttpRequest originalRequest = requestWasWrapped(request) ?
((RequestWrapper)request).getOriginal() : request;
if (originalRequest instanceof HttpEntityEnclosingRequest) {
if (((HttpEntityEnclosingRequest)originalRequest).expectContinue()) return;
}
consumeBody(response);
throw new ClientProtocolException(UNEXPECTED_100_CONTINUE);
}
private void transferEncodingIsNotReturnedTo1_0Client(HttpRequest request, HttpResponse response) {
if (!requestWasWrapped(request)) {
return;
}
ProtocolVersion originalProtocol = getOriginalRequestProtocol((RequestWrapper) request);
if (originalProtocol.compareToVersion(HttpVersion.HTTP_1_1) >= 0) {
return;
}
removeResponseTransferEncoding(response);
}
private void removeResponseTransferEncoding(HttpResponse response) {
response.removeHeaders("TE");
response.removeHeaders(HTTP.TRANSFER_ENCODING);
}
private ProtocolVersion getOriginalRequestProtocol(RequestWrapper request) {
return request.getOriginal().getProtocolVersion();
}
private boolean requestWasWrapped(HttpRequest request) {
return request instanceof RequestWrapper;
}
}