Increasing minimum supported JDK (and dropping support for JDK 11)

[cushon]

Following the example of google/error-prone#3803, we're considering removing support for running google-java-format on JDK 11. The new minimum supported JDK would be JDK 17 (the next LTS release after 11).

google-java-format would still fully support formatting earlier source code versions, it would just require running the tool on JDK 17 or later.

[sormuras]

Doesn't the runtime version determine the source code version at the moment? Or does GJF support a --source 11 option? 🤔

[tbroyer]

Afaict it determines what can be parsed but not how it'll be formatted.

[cushon]

Afaict it determines what can be parsed but not how it'll be formatted.

Right, it'll parse at whatever the newest language level supported by the runtime is, and shouldn't affect formatting. Newer source versions are usually a superset of older ones, but there are some occasional breaking changes like new reserved identifiers, #975 is a related FR about making the source version g-j-f parses at configurable.