Java 17 SE

2021. 9. 14. Released.

Summary

JEP 306: Restore Always-Strict Floating-Point Semantics
JEP 356: Enhanced Pseudo-Random Number Generators
JEP 382: New macOS Rendering Pipeline
JEP 391: macOS/AArch64 Port
JEP 398: ~~Applet API~~ deprecated
JEP 403: Strongly Encapsulate JDK Internals
JEP 406: switch 패턴 매칭 (Preview)
JEP 407: ~~RMI Activation~~ 제거
JEP 409: 봉인된 클래스(sealed)
JEP 410: ~~AOT~~ and ~~JIT Compiler~~
JEP 411: Deprecate the ~~Security Manager~~ for Removal
JEP 412: Foreign Function & Memory API (Incubator)
JEP 414: Vector API (Second Incubator)
JEP 415: Context-Specific Deserialization Filters

JEP 406에서는 switch 구문 및 표현에서 instanceof 연산자가 사용된 패턴 매칭 문법이 확장되었다. 재정의된 패턴, 널 케이스, 인수 타입 기반등의 케이스가 허용된다.

Object o = ...;
return switch (o) {
        case null       -> "Null";
        case String s   -> String.format("String %s", s);
        case Long l     -> String.format("long %d", l);
        case Double d   -> String.format("double %f", d);
        case Integer i && i > 0                            // refining patterns
                        -> String.format("positive int %d", i);
        case Integer i && i == 0 
                        -> String.format("zero int %d", i);
        case Integer i && i < 0 
                        -> String.format("negative int %d", i);
        default         -> o.toString();
    };
};