This document discusses HTTP caching tips and tricks. It explains that caching can decrease traffic, increase loading speed, require less code, and allow offline use. It provides code to enable caching and describes headers for content validation, cache checking, and cache management. These techniques can help optimize performance by leveraging cached responses when possible.

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HTTP Cache
Tips & Tricks (RFC 2616)
Alexander Sergienko
Senior Developer @ DataArt

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Why do I need to do this?
• Decrease traffic
• Increase loading speed
• Write less lines of code
• Offline mode

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How can I do this?
URL DATA CREATED_AT UPDATED_AT HASH_CODE
TEXT
BLOB TEXT TEXT TEXT
Enable HTTP cache
private void enableHttpResponseCache() {
try {
long httpCacheSize = 10 * 1024 * 1024; // 10 MiB
File httpCacheDir = new File(getExternalCacheDir(), "http");
HttpResponseCache.install(httpCacheDir, httpCacheSize);
} catch (Exception httpResponseCacheNotAvailable) {
Log.d(TAG, "HTTP response cache is unavailable.");
}
}

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Will it work?

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Content validation headers
Request headers Response headers
If-Modified-Since (HTTP Date) Last-Modified (HTTP Date)
If-None-Match (Object Hash) ETag (Object Hash)
HTTP Date
RFC 822, updated by RFC 1123 Sun, 06 Nov 1994 08:49:37 GMT
RFC 822, updated by RFC 1123 Sunday, 06-Nov-94 08:49:37 GMT
RFC 822, updated by RFC 1123 Sun Nov 6 08:49:37 1994

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Check cache

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Cache managing headers
Request headers Response headers
Cache-Control ("no-cache" ;
"no-store"; "max-age" "="
delta-seconds ; "max-stale" "="
delta-seconds; "min-fresh" "="
delta-seconds ; "no-transform";
"only-if-cached")
Cache-Control ("public";
"private"; "no-cache"; "no-
store"; "no-transform"; "must-
revalidate"; "proxy-
revalidate"; "max-age" "="
delta-seconds; "s-maxage" "="
delta-seconds)
Pragma (no-cache)
Expires (HTTP Date)

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Alexander Sergienko
https://www.linkedin.com/in/alexandr-sergienko-3874b491
Q&A
Thank you!