[Java] JDK 버전별 차이점 정리 (1.5~17)

※ 2021년 11월 26일에 작성된 글입니다.

JDK 1.5

추가된 기능

• Generic
• Metadata
• Autoboxing/unboxing
• Enumerations
• Varargs
• Enhanced for each loop
• Improved semantics of execution for multi-threaded Java programs
• Static imports

표준 라이브러리 개선

• Automatic stub generation for RMI objects
• Swing
• The concurrency utilities in package java.util.concurrent
• Scanner class for parsing data from various input streams and buffers

JDK 1.6

• Support for older Win9x versions dropped
• Scripting Language Support
• Dramatic performance improvements for the core platform, and Swing.
• Improved Web Service support through JAX-WS.
• JDBC 4.0 support.
• Java Compiler API
• Upgrade of JAXB to version 2.0: Including integration of a StAX parser.
• Support for pluggable annotations.
• Many GUI improvements, such as integration of SwingWorker in the API, table sorting and filtering, and true Swing double-buffering (eliminating the gray-area effect).
• JVM improvements include: synchronization and compiler performance optimizations, new algorithms and upgrades to existing garbage collection algorithms, and application start-up performance.

JDK 1.7

• JVM support for dynamic languages, with the new invokedynamic bytecode under JSR-292, following the prototyping work currently done on the Multi Language Virtual Machine
• Compressed 64-bit pointers (available in Java 6 with -XX:+UseCompressedOops)
• These small language changes (grouped under a project named Coin):
  • Strings in switch
  • Automatic resource management in try-statement
  • Improved type inference for generic instance creation, aka the diamond operator <>
  • Simplified varargs method declaration
  • Binary integer literals
  • Allowing underscores in numeric literals
  • Catching multiple exception types and rethrowing exceptions with improved type checking
• Concurrency utilities under JSR 166
• New file I/O library (defined by JSR 203) adding support for multiple file systems, file metadata and symbolic links. The new packages are java.nio.file, java.nio.file.attribute and java.nio.file.spi
• Timsort is used to sort collections and arrays of objects instead of merge sort
• Library-level support for elliptic curve cryptography algorithms
• An XRender pipeline for Java 2D, which improves handling of features specific to modern GPUs
• New platform APIs for the graphics features originally implemented in version 6u10 as unsupported APIs
• Enhanced library-level support for new network protocols, including SCTP and Sockets Direct Protocol
• Upstream updates to XML and Unicode
• Java deployment rule sets

JDK 1.8

• Language-level support for lambda expressions
• default methods (virtual extension methods) which allow the addition of methods to interfaces without breaking existing implementations
• a JavaScript runtime which allows developers to embed JavaScript code within applications
• Annotation on Java types
• Unsigned integer arithmetic
• Repeating annotations
• Date and time API
• Statically-linked JNI libraries
• Launch JavaFX applications (direct launching of JavaFX application JARs)
• Remove the permanent generation

JDK 9

• Modularization of the JDK under Project Jigsaw (Java Platform Module System)
• JavaDB was removed from JDK
• Variable handles
• Milling Project Coin : Allow @SafeVarargs on private instance methods; Allow effectively-final variables to be used as resources in the try-with-resources statement; Allow diamond with anonymous classes if the argument type of the inferred type is denotable; Complete the removal, begun in Java SE 8, of underscore from the set of legal identifier names; Support for private methods in interfaces
• jshell: The Java Shell (Read-Eval-Print Loop) : JShell is a REPL command-line interface for the Java language.
• Compact Strings
• HiDPI graphics: automatic scaling and sizing
• More concurrency updates : It includes a Java implementation of Reactive Streams, including a new Flow class that included the interfaces previously provided by Reactive Streams
• XML catalogs
• jlink: The Java Linker : create a tool that can assemble and optimize a set of modules and their dependencies into a custom run-time image. It effectively allows to produce a fully usable executable including the JVM to run it
• Ahead-of-Time Compilation : Ahead-of-time compilation provided by GraalVM.

JDK 10

• Local-Variable Type Inference
• Consolidate the JDK Forest into a Single Repository
• Garbage-Collector Interface
• Parallel Full GC for G1
• Application Class-Data Sharing
• Thread-Local Handshakes
• Remove the Native-Header Generation Tool (javah)
• Additional Unicode Language-Tag Extensions
• Heap Allocation on Alternative Memory Devices
• Experimental Java-Based JIT Compiler
• Root Certificates
• Time-Based Release Versioning

JDK 11

• Nest-Based Access Control
• Dynamic Class-File Constants
• Improve Aarch64 Intrinsics
• Epsilon: A No-Op Garbage Collector
• Remove the Java EE and CORBA Modules
• HTTP Client (Standard)
• Local-Variable Syntax for Lambda Parameters
• Key Agreement with Curve25519 and Curve448
• Unicode 10
• Flight Recorder
• ChaCha20 and Poly1305 Cryptographic Algorithms
• Launch Single-File Source-Code Programs
• Low-Overhead Heap Profiling
• Transport Layer Security (TLS) 1.3
• ZGC: A Scalable Low-Latency Garbage Collector (Experimental)
• Deprecate the Nashorn JavaScript Engine
• Deprecate the Pack200 Tools and API

JDK 12

• Shenandoah: A Low-Pause-Time Garbage Collector (Experimental)
• Microbenchmark Suite
• Switch Expressions (Preview)
• JVM Constants API
• One AArch64 Port, Not Two
• Default CDS Archives
• Abortable Mixed Collections for G1
• Promptly Return Unused Committed Memory from G1

JDK 13

• Dynamic CDS Archives
• ZGC: Uncommit Unused Memory
• Reimplement the Legacy Socket API
• Switch Expressions (Second Preview)
• Text Blocks (Preview)

JDK 14

• Pattern Matching for instanceof (Preview)
• Packaging Tool (Incubator)
• NUMA-Aware Memory Allocation for G1
• JFR Event Streaming
• Non-Volatile Mapped Byte Buffers
• Helpful NullPointerExceptions
• Records (Preview)
• Switch Expressions (Standard)
• Deprecate the Solaris and SPARC Ports
• Remove the Concurrent Mark Sweep (CMS) Garbage Collector
• ZGC on macOS
• ZGC on Windows
• Deprecate the ParallelScavenge + SerialOld GC Combination
• Remove the Pack200 Tools and API
• Text Blocks (Second Preview)
• Foreign-Memory Access API (Incubator)

JDK 15

• Edwards-Curve Digital Signature Algorithm (EdDSA)
• Sealed Classes (Preview)
• Hidden Classes
• Remove the Nashorn JavaScript Engine
• Reimplement the Legacy DatagramSocket API
• Disable and Deprecate Biased Locking
• Pattern Matching for instanceof (Second Preview)
• ZGC: A Scalable Low-Latency Garbage Collector
• Text Blocks
• Shenandoah: A Low-Pause-Time Garbage Collector
• Remove the Solaris and SPARC Ports
• Foreign-Memory Access API (Second Incubator)
• Records (Second Preview)
• Deprecate RMI Activation for Removal

JDK 16

• Vector API (Incubator)
• Enable C++14 Language Features
• Migrate from Mercurial to Git
• Migrate to GitHub
• ZGC: Concurrent Thread-Stack Processing
• Unix-Domain Socket Channels
• Alpine Linux Port – not yet stable
• Elastic Metaspace
• Windows/AArch64 Port
• Foreign Linker API (Incubator)
• Warnings for Value-Based Classes
• Packaging Tool
• Foreign-Memory Access API (Third Incubator)
• Pattern Matching for instanceof
• Records
• Strongly Encapsulate JDK Internals by Default
• Sealed Classes (Second Preview)

JDK 17

• Restore Always-Strict Floating-Point Semantics
• Enhanced Pseudo-Random Number Generators
• New macOS Rendering Pipeline
• macOS/AArch64 Port
• Deprecate the Applet API for Removal
• Strongly Encapsulate JDK Internals
• Pattern Matching for switch (Preview)
• Remove RMI Activation
• Sealed Classes
• Remove the Experimental AOT and JIT Compiler
• Deprecate the Security Manager for Removal
• Foreign Function & Memory API (Incubator)
• Vector API (Second Incubator)
• Context-Specific Deserialization Filters

참고 자료

• JEP 0 JEP Index
• Java version history - Wikipedia