Java Profile

src/main/java/
    space/example/project/
        api/
        runtime/
        service/
        network/
        storage/
        model/

Avoid generic dumping grounds such as util/, manager/, misc/, or helper/ unless the package has a real and narrow purpose.

SessionService
PacketRegistry
UserStorage
ConnectionState

Interfaces use the I prefix:

ISession
IStorage
IPacket
IConnection

open()
close()
load()
save()
execute()
resolve()

request
session
player
connection

Single-letter variables are disallowed unless they are established local conventions such as loop counters.

public record SessionId(UUID value) {
}

Avoid boilerplate POJOs when a record is sufficient.

Objects.requireNonNull(value);

for normal control-flow validation.

if (value == null) {
    return;
}

if (config == null) {
    throw new ConfigurationException("Missing configuration");
}

records
sealed types
pattern matching
switch expressions
var
virtual threads
text blocks
streams

Modern syntax should reduce noise, not create novelty for its own sake.

return switch (state) {
    case READY -> start();
    case CLOSED -> stop();
    case FAILED -> recover();
};

Prefer this over long chains of unrelated state checks.

Do not block main or tick threads with HTTP, database operations, filesystem access, or blocking network I/O.

Virtual threads are preferred for blocking I/O where appropriate.

Streams are encouraged when they improve readability. Use a loop if it is clearer, easier to debug, or better suited to the hot path.

Anything that is opened, registered, started, allocated, or subscribed must have an equally clear corresponding close, unregister, stop, release, or unsubscribe path.