Replace CacheFiles by JCS?

[simon04]

While investigating #11867, I came across org.openstreetmap.josm.io.CacheFiles. This class is only used in ThumbsLoader and might be replaced by a JCS cache?

[wiktorn]

I doesn't look like hard thing. I attach a patch that does this for review. But I didn't it test thoroughly yet.

[simon04]

Some thoughts:

• When the cache initialization fails (IOException in the constructor), we will run into NPE while accessing the cache. So check for cache != null in if (!cacheOff) (2×)?
• Maybe you can give some context for the Main.warn calls, e.g., "Thumbnail cache initialization failed" and "Thumbnail cache access failed".
• Java 7 provides the try (ByteArrayOutputStream output = new ByteArrayOutputStream()) { /* ... */ } construct to automatically close the stream at the end. Might not be necessary for ByteArrayOutputStream, but is used through-out the code …

[wiktorn]

In 8762/josm:

Replace CacheFiles with JCS and remove CacheFiles

Closes: #11869

[wiktorn]

@simon04

Thanks for your review.