Java 17

Java 17 (2021) - LTS:

1. Sealed Classes (standard): The preview feature from Java 15 became standard.

2. Pattern Matching for switch (preview): Extended pattern matching to switch statements and expressions.

String formatted = switch (obj) {
    case Integer i -> String.format("int %d", i);
    case Long l    -> String.format("long %d", l);
    case Double d  -> String.format("double %f", d);
    case String s  -> String.format("String %s", s);
    default        -> obj.toString();
};

1. Strong encapsulation of JDK internals: Further restricted access to internal APIs.