我试图利用HttpResponseCache,但没有运气得到它的工作。
我是这样安装的:
SdCardManager manager = SdCardManager.getSdCardManager(context);
File dir = new File(manager.getAbsolutePathForSdCardFile(""), "http");
Log.e("Test", "Installing cache to " + dir.getAbsolutePath());
HttpResponseCache.install(dir, 10 * 1024 * 1024);
和我的连接代码是:
try{
URL url = new URL(mUrl);
HttpURLConnection connection = (HttpURLConnection) ((mProxy == null) ? url
.openConnection() : url.openConnection(mProxy.getProxy()));
HttpResponseCache cache = HttpResponseCache.getInstalled();
Log.e("Test", "Req count: " + cache.getRequestCount() + " hit count " + cache.getHitCount() + " size = " + cache.size());
connection.setUseCaches(true);
connection.setDefaultUseCaches(true);
connection.addRequestProperty("Cache-Control", "max-stale=" + (60 * 60 * 24 * 28));
applyHeaders(connection);
connection.setRequestMethod("GET");
connection.setConnectTimeout(mTimeout);
connection.setReadTimeout(mTimeout);
connection.connect();
mStatusCode = connection.getResponseCode();
mStatusMessage = connection.getResponseMessage();
connection.disconnect();
}
catch (IOException ex) {
ex.printStackTrace();
return false;
}
在adb shell中,我看到正在创建缓存目录,它有一个日志文件。但是,不再向目录发送任何数据:
shell@maguro:/storage/emulated/legacy/Android/data/com.snip.pre/files/http $ ls
journal
每次请求后刷新缓存:
HttpResponseCache cache = HttpResponseCache.getInstalled();
cache.flush();
你知道我做错了什么吗?服务器的响应头在这里:
GET /imgv.oms/0.0.1fd02.a7003c2a HTTP/1.1
Cache-Control: max-stale=2419200
Authorization: Basic bWFydGlubDppc2lz
X-Loginpageredirect: none
Accept: image/*
Accept-Encoding: gzip,deflate
Accept-Language: en-GB
User-Agent: Dalvik/1.6.0 (Linux; U; Android 4.3; Galaxy Nexus Build/JWR66Y)
Host: appsdev2.server.com:81
Connection: Keep-Alive
Cookie: POSESSIONID=F8654323-f7frSyNmAGKsvE4nFXZJQIIy3Io
是否有任何东西阻止它被缓存?
问题是,我正在发送授权头,而标准对这些请求是否可缓存有特定的规则。看到
http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html section 14.8
服务器不允许我缓存结果,正如njzk2所暗示的那样。