/*
* ====================================================================
* 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.client.cache;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import org.apache.http.Header;
import org.apache.http.HeaderElement;
import org.apache.http.HttpEntityEnclosingRequest;
import org.apache.http.HttpRequest;
import org.apache.http.HttpResponse;
import org.apache.http.HttpStatus;
import org.apache.http.HttpVersion;
import org.apache.http.ProtocolVersion;
import org.apache.http.annotation.Immutable;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.cache.HeaderConstants;
import org.apache.http.impl.client.RequestWrapper;
import org.apache.http.impl.cookie.DateParseException;
import org.apache.http.impl.cookie.DateUtils;
import org.apache.http.message.BasicHeader;
import org.apache.http.protocol.HTTP;
/**
* @since 4.1
*/
@Immutable
class ResponseProtocolCompliance {
/**
* 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 ClientProtocolException when we are unable to 'convert' the response to a compliant one
*/
public void ensureProtocolCompliance(HttpRequest request, HttpResponse response)
throws ClientProtocolException {
if (backendResponseMustNotHaveBody(request, response)) {
response.setEntity(null);
}
authenticationRequiredDidNotHaveAProxyAuthenticationHeader(request, response);
notAllowedResponseDidNotHaveAnAllowHeader(request, response);
unauthorizedResponseDidNotHaveAWWWAuthenticateHeader(request, response);
requestDidNotExpect100ContinueButResponseIsOne(request, response);
transferEncodingIsNotReturnedTo1_0Client(request, response);
ensurePartialContentIsNotSentToAClientThatDidNotRequestIt(request, response);
ensure200ForOPTIONSRequestWithNoBodyHasContentLengthZero(request, response);
ensure206ContainsDateHeader(response);
identityIsNotUsedInContentEncoding(response);
warningsWithNonMatchingWarnDatesAreRemoved(response);
}
private void warningsWithNonMatchingWarnDatesAreRemoved(
HttpResponse response) {
Date responseDate = null;
try {
responseDate = DateUtils.parseDate(response.getFirstHeader("Date").getValue());
} catch (DateParseException e) {
}
if (responseDate == null) return;
Header[] warningHeaders = response.getHeaders("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("Warning",wv.toString()));
} else {
modified = true;
}
}
}
if (modified) {
response.removeHeaders("Warning");
for(Header h : newWarningHeaders) {
response.addHeader(h);
}
}
}
private void identityIsNotUsedInContentEncoding(HttpResponse response) {
Header[] hdrs = response.getHeaders("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("Content-Encoding", newHeaderValue));
}
}
if (!modified) return;
response.removeHeaders("Content-Encoding");
for (Header h : newHeaders) {
response.addHeader(h);
}
}
private void authenticationRequiredDidNotHaveAProxyAuthenticationHeader(HttpRequest request,
HttpResponse response) throws ClientProtocolException {
if (response.getStatusLine().getStatusCode() != HttpStatus.SC_PROXY_AUTHENTICATION_REQUIRED)
return;
if (response.getFirstHeader(HeaderConstants.PROXY_AUTHENTICATE) == null)
throw new ClientProtocolException(
"407 Response did not contain a Proxy-Authentication header");
}
private void notAllowedResponseDidNotHaveAnAllowHeader(HttpRequest request,
HttpResponse response) throws ClientProtocolException {
if (response.getStatusLine().getStatusCode() != HttpStatus.SC_METHOD_NOT_ALLOWED)
return;
if (response.getFirstHeader(HeaderConstants.ALLOW) == null)
throw new ClientProtocolException("405 Response did not contain an Allow header.");
}
private void unauthorizedResponseDidNotHaveAWWWAuthenticateHeader(HttpRequest request,
HttpResponse response) throws ClientProtocolException {
if (response.getStatusLine().getStatusCode() != HttpStatus.SC_UNAUTHORIZED)
return;
if (response.getFirstHeader(HeaderConstants.WWW_AUTHENTICATE) == null) {
throw new ClientProtocolException(
"401 Response did not contain required WWW-Authenticate challenge header");
}
}
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 ClientProtocolException {
if (request.getFirstHeader(HeaderConstants.RANGE) != null)
return;
if (response.getFirstHeader(HeaderConstants.CONTENT_RANGE) != null) {
throw new ClientProtocolException(
"Content-Range was returned for a request that did not ask for a Content-Range.");
}
}
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 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 ClientProtocolException {
if (response.getStatusLine().getStatusCode() != HttpStatus.SC_CONTINUE) {
return;
}
if (!requestWasWrapped(request)) {
return;
}
ProtocolVersion originalProtocol = getOriginalRequestProtocol((RequestWrapper) request);
if (originalProtocol.compareToVersion(HttpVersion.HTTP_1_1) >= 0) {
return;
}
if (originalRequestDidNotExpectContinue((RequestWrapper) request)) {
throw new ClientProtocolException("The incoming request did not contain a "
+ "100-continue header, but the response was a Status 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 boolean originalRequestDidNotExpectContinue(RequestWrapper request) {
try {
HttpEntityEnclosingRequest original = (HttpEntityEnclosingRequest) request
.getOriginal();
return !original.expectContinue();
} catch (ClassCastException ex) {
return false;
}
}
private ProtocolVersion getOriginalRequestProtocol(RequestWrapper request) {
return request.getOriginal().getProtocolVersion();
}
private boolean requestWasWrapped(HttpRequest request) {
return request instanceof RequestWrapper;
}
}