HTTP compression with Spring Boot and Nginx - spring

Question

I am having a setting with an Nginx reverse proxy, a Spring Boot application, and a (Redis) cache, and would like to ask you (1) how to configure Nginx to only compress the data if it is not compressed yet, and (2) how to send compressed and cache data in Spring Boot correctly.
Current setup
The Nginx acts as a reverse proxy and compresses the data with specified content types:
gzip on;
gzip_types text/plain text/css application/json application/javascript text/xml application/xml application/xml+rss text/javascript;
The Spring Boot API application has a few compute-intense endpoints that manage their own cache and many lightweight endpoints that don't need caching. The response sizes are often quite large (up to multiple hundred MBs) so that the data are compressed before caching. In pseudo-code:
#RequestMapping("/uncached1")
public MyUncached1Response getUncachedData1(String query) {
return dataservice.getResults1(query);
}
#RequestMapping("/cached1")
public String getCachedData1(String query) {
if (cache.has(query)) {
return uncompress(cache.get(query));
} else {
String results = dataservice.getResults2(query);
cache.set(query, compress(results));
return results;
}
}
As you can see, the setup is compressing and uncompressing a lot. If the value has not been cached, the application compresses the results for the cache. Then, the application returns the uncompressed data and Nginx compresses it again. If the value is already in the cache, the application first uncompresses it and gives Nginx the uncompressed data for compression.
Envisioned setup
I am wondering if the following setup would be possible:
Nginx only compresses the data if it has not been compressed yet
Some endpoints of the Spring Boot application returns compressed data if the client accepts it:
#RequestMapping("/uncached1")
public MyUncached1Response getUncachedData1(String query) {
return dataservice.getResults1(query);
}
#RequestMapping("/cached1")
public byte[] getCachedData1(String query) {
if (cache.has(query)) {
byte[] compressed = cache.get(query);
if (client.acceptsGzip()) {
return compressed;
} else {
return uncompressed(compressed).toByteArray();
}
} else {
String results = dataservice.getResults2(query);
byte[] compressed = compress(results);
cache.set(query, compressed);
if (client.acceptsGzip()) {
return compressed;
} else {
return results.toByteArray();
}
}
}
Questions:
Does the envisioned setup make sense, is it possible? If yes, could you please provide me with some hints for the implementation?
If it doesn't work this way, what would be a better architecture?
Currently, I use Java's Deflater for compression, but that's not entirely the same as gzip, right? How can I compress the data compatible to gzip for HTTP?
How can I see whether the client accepts gzip?
Thanks so much!