1 /* 2 * Copyright (C) 2014 Square, Inc. 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 package com.squareup.okhttp.internal.huc; 17 18 import com.squareup.okhttp.Request; 19 import com.squareup.okhttp.Response; 20 import com.squareup.okhttp.internal.InternalCache; 21 import com.squareup.okhttp.internal.http.CacheRequest; 22 import com.squareup.okhttp.internal.http.CacheStrategy; 23 import java.io.IOException; 24 import java.io.OutputStream; 25 import java.net.CacheResponse; 26 import java.net.HttpURLConnection; 27 import java.net.ResponseCache; 28 import java.net.URI; 29 import java.util.List; 30 import java.util.Map; 31 import okio.Okio; 32 import okio.Sink; 33 34 /** Adapts {@link ResponseCache} to {@link InternalCache}. */ 35 public final class CacheAdapter implements InternalCache { 36 private final ResponseCache delegate; 37 38 public CacheAdapter(ResponseCache delegate) { 39 this.delegate = delegate; 40 } 41 42 public ResponseCache getDelegate() { 43 return delegate; 44 } 45 46 @Override public Response get(Request request) throws IOException { 47 CacheResponse javaResponse = getJavaCachedResponse(request); 48 if (javaResponse == null) { 49 return null; 50 } 51 return JavaApiConverter.createOkResponseForCacheGet(request, javaResponse); 52 } 53 54 @Override public CacheRequest put(Response response) throws IOException { 55 URI uri = response.request().uri(); 56 HttpURLConnection connection = JavaApiConverter.createJavaUrlConnectionForCachePut(response); 57 final java.net.CacheRequest request = delegate.put(uri, connection); 58 if (request == null) { 59 return null; 60 } 61 return new CacheRequest() { 62 @Override public Sink body() throws IOException { 63 OutputStream body = request.getBody(); 64 return body != null ? Okio.sink(body) : null; 65 } 66 67 @Override public void abort() { 68 request.abort(); 69 } 70 }; 71 } 72 73 @Override public void remove(Request request) throws IOException { 74 // This method is treated as optional and there is no obvious way of implementing it with 75 // ResponseCache. Removing items from the cache due to modifications made from this client is 76 // not essential given that modifications could be made from any other client. We have to assume 77 // that it's ok to keep using the cached data. Otherwise the server shouldn't declare it as 78 // cacheable or the client should be careful about caching it. 79 } 80 81 @Override public void update(Response cached, Response network) throws IOException { 82 // This method is treated as optional and there is no obvious way of implementing it with 83 // ResponseCache. Updating headers is useful if the server changes the metadata for a resource 84 // (e.g. max age) to extend or truncate the life of that resource in the cache. If the metadata 85 // is not updated the caching behavior may not be optimal, but will obey the metadata sent 86 // with the original cached response. 87 } 88 89 @Override public void trackConditionalCacheHit() { 90 // This method is optional. 91 } 92 93 @Override public void trackResponse(CacheStrategy cacheStrategy) { 94 // This method is optional. 95 } 96 97 /** 98 * Returns the {@link CacheResponse} from the delegate by converting the 99 * OkHttp {@link Request} into the arguments required by the {@link ResponseCache}. 100 */ 101 private CacheResponse getJavaCachedResponse(Request request) throws IOException { 102 Map<String, List<String>> headers = JavaApiConverter.extractJavaHeaders(request); 103 return delegate.get(request.uri(), request.method(), headers); 104 } 105 } 106
