| /* |
| * ==================================================================== |
| * 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.hc.client5.http.impl.cache; |
| |
| import java.io.UnsupportedEncodingException; |
| import java.net.URI; |
| import java.net.URISyntaxException; |
| import java.net.URLEncoder; |
| import java.nio.charset.StandardCharsets; |
| import java.util.ArrayList; |
| import java.util.Collections; |
| import java.util.Iterator; |
| import java.util.List; |
| |
| import org.apache.hc.client5.http.cache.HeaderConstants; |
| import org.apache.hc.client5.http.cache.HttpCacheEntry; |
| import org.apache.hc.core5.annotation.Contract; |
| import org.apache.hc.core5.annotation.ThreadingBehavior; |
| import org.apache.hc.core5.function.Resolver; |
| import org.apache.hc.core5.http.Header; |
| import org.apache.hc.core5.http.HeaderElement; |
| import org.apache.hc.core5.http.HttpHost; |
| import org.apache.hc.core5.http.HttpRequest; |
| import org.apache.hc.core5.http.message.MessageSupport; |
| |
| /** |
| * @since 4.1 |
| */ |
| @Contract(threading = ThreadingBehavior.STATELESS) |
| public class CacheKeyGenerator implements Resolver<URI, String> { |
| |
| public static final CacheKeyGenerator INSTANCE = new CacheKeyGenerator(); |
| |
| @Override |
| public String resolve(final URI uri) { |
| return generateKey(uri); |
| } |
| |
| /** |
| * Computes a key for the given request {@link URI} that can be used as |
| * a unique identifier for cached resources. The URI is expected to |
| * in an absolute form. |
| * |
| * @param requestUri request URI |
| * @return cache key |
| */ |
| public String generateKey(final URI requestUri) { |
| try { |
| final URI normalizeRequestUri = HttpCacheSupport.normalize(requestUri); |
| return normalizeRequestUri.toASCIIString(); |
| } catch (final URISyntaxException ex) { |
| return requestUri.toASCIIString(); |
| } |
| } |
| |
| /** |
| * Computes a key for the given {@link HttpHost} and {@link HttpRequest} |
| * that can be used as a unique identifier for cached resources. |
| * |
| * @param host The host for this request |
| * @param request the {@link HttpRequest} |
| * @return cache key |
| */ |
| public String generateKey(final HttpHost host, final HttpRequest request) { |
| final String s = HttpCacheSupport.getRequestUri(request, host); |
| try { |
| return generateKey(new URI(s)); |
| } catch (final URISyntaxException ex) { |
| return s; |
| } |
| } |
| |
| private String getFullHeaderValue(final Header[] headers) { |
| if (headers == null) { |
| return ""; |
| } |
| final StringBuilder buf = new StringBuilder(""); |
| for (int i = 0; i < headers.length; i++) { |
| final Header hdr = headers[i]; |
| if (i > 0) { |
| buf.append(", "); |
| } |
| buf.append(hdr.getValue().trim()); |
| } |
| return buf.toString(); |
| } |
| |
| /** |
| * Computes a key for the given {@link HttpHost} and {@link HttpRequest} |
| * that can be used as a unique identifier for cached resources. if the request has a |
| * {@literal VARY} header the identifier will also include variant key. |
| * |
| * @param host The host for this request |
| * @param request the {@link HttpRequest} |
| * @param entry the parent entry used to track the variants |
| * @return cache key |
| */ |
| public String generateKey(final HttpHost host, final HttpRequest request, final HttpCacheEntry entry) { |
| if (!entry.hasVariants()) { |
| return generateKey(host, request); |
| } |
| return generateVariantKey(request, entry) + generateKey(host, request); |
| } |
| |
| /** |
| * Computes a "variant key" from the headers of a given request that are |
| * covered by the Vary header of a given cache entry. Any request whose |
| * varying headers match those of this request should have the same |
| * variant key. |
| * @param req originating request |
| * @param entry cache entry in question that has variants |
| * @return variant key |
| */ |
| public String generateVariantKey(final HttpRequest req, final HttpCacheEntry entry) { |
| final List<String> variantHeaderNames = new ArrayList<>(); |
| final Iterator<HeaderElement> it = MessageSupport.iterate(entry, HeaderConstants.VARY); |
| while (it.hasNext()) { |
| final HeaderElement elt = it.next(); |
| variantHeaderNames.add(elt.getName()); |
| } |
| Collections.sort(variantHeaderNames); |
| |
| final StringBuilder buf; |
| try { |
| buf = new StringBuilder("{"); |
| boolean first = true; |
| for (final String headerName : variantHeaderNames) { |
| if (!first) { |
| buf.append("&"); |
| } |
| buf.append(URLEncoder.encode(headerName, StandardCharsets.UTF_8.name())); |
| buf.append("="); |
| buf.append(URLEncoder.encode(getFullHeaderValue(req.getHeaders(headerName)), |
| StandardCharsets.UTF_8.name())); |
| first = false; |
| } |
| buf.append("}"); |
| } catch (final UnsupportedEncodingException uee) { |
| throw new RuntimeException("couldn't encode to UTF-8", uee); |
| } |
| return buf.toString(); |
| } |
| |
| } |