JDK 1.8 / Java 8 (자바 8)의 새 기능 주요 특징과 설명 New features #1

JDK 1.8 / Java 8 (자바 8)의 새 기능 주요 특징과 설명 New features #1

1 Lambda Expressions & Virtual Extension Methods
Add lambda expressions (closures) and supporting features, including method references, enhanced type inference, and virtual extension methods, to the Java programming language and platform.

2 Autoconf-Based Build System
Introduce autoconf (./configure-style) build setup, refactor the Makefiles to remove recursion, and leverage JEP 139: Enhance javac to Improve Build Speed.

3 Lambda-Form Representation for Method Handles
Improve the implementation of method handles by replacing assembly language paths with an optimizable intermediate representation and then refactoring the implementation so that more work is done in portable Java code than is hardwired into the JVM.

4 Compact Profiles
Define a few subset Profiles of the Java SE Platform Specification so that applications that do not require the entire Platform can be deployed and run on small devices.

5 Prepare for Modularization
Undertake changes to smooth the eventual transition to modules in a future release, provide new tools to help developers prepare for the modular platform, and deprecate certain APIs that are a significant impediment to modularization.

6 Leverage CPU Instructions for AES Cryptography
Improve the out-of-box AES Crypto performance by using x86 AES instructions when available, and by avoiding unnecessary re-expansion of the AES key.

7 Nashorn JavaScript Engine
Design and implement a new lightweight, high-performance implementation of JavaScript, and integrate it into the JDK. The new engine will be made available to Java applications via the existing javax.script API, and also more generally via a new command-line tool.

8 Mechanical Checking of Caller-Sensitive Methods
Improve the security of the JDK’s method-handle implementation by replacing the existing hand-maintained list of caller-sensitive methods with a mechanism that accurately identifies such methods and allows their callers to be discovered reliably.

9 Document JDK API Support and Stability
"There is a long-standing shortcoming in the JDK in terms of clearly specifying the support and stability usage contract for com.sun.* types and other types shipped with the JDK that are outside of the Java SE specification. These contracts and potential evolution policies should be clearly captured both in the source code of the types and in the resulting class files. This information can be modeled with JDK-specific annotation types."

Here are few code examples of lambda expressions usage.

An example of what you would do today:

btn.setOnAction(new EventHandler<ActionEvent>() {     @Override     public void handle(ActionEvent event) {         System.out.println("Hello World!");     } });

With lambda in java 8 you just have:

btn.setOnAction(     event -> System.out.println("Hello World!") );