The JDK is the Coffee Development Kit, the full-featured SDK for Coffee. Information technology has everything the JRE has, but also the compiler (javac) and tools (like javadoc and jdb). It is capable of creating and compiling programs.

The new Oracle Technology Network License Understanding for Oracle Java SE is substantially unlike from prior Oracle JDK licenses. The new license permits certain uses, such equally personal utilise and development use, at no cost -- but other uses authorized under prior Oracle JDK licenses may no longer be available.

Sometimes, even if you are not planning to do whatever Java evolution on a computer, you still need the JDK installed. For example, if you lot are deploying a web application with JSP, you are technically just running Java programs inside the application server. Why would y'all need the JDK then? Considering the application server will convert JSP into Coffee servlets and needs to use the JDK to compile the servlets.

What'due south New:

The total version string for this update release is 16.0.2+vii (where "+" means "build"). The version number is 16.0.two.

This section describes some of the enhancements in Java SE sixteen and JDK 16. In some cases, the descriptions provide links to additional detailed information about an consequence or a change. The APIs described here are those that are provided with the Oracle JDK. It includes a complete implementation of the Java SE 16 Platform and additional Java APIs to support developing, debugging, and monitoring Java applications. Another source of data nearly important enhancements and new features in Coffee SE 16 and JDK 16 is the Coffee SE sixteen ( JSR 391) Platform Specification, which documents the changes to the specification made between Java SE 15 and Coffee SE sixteen. This document includes descriptions of those new features and enhancements that are also changes to the specification. The descriptions likewise identify potential compatibility issues that you might encounter when migrating to JDK 16.

IANA TZ Data 2021a

  • JDK 16.0.two contains IANA time zone information 2021a.

JEP 389: Foreign Linker API (Incubator)

  • Introduce an API that offers statically-typed, pure-Java admission to native lawmaking. This API, together with the Foreign-Memory API (JEP 393), will considerably simplify the otherwise mistake-prone procedure of binding to a native library.

JEP 396: Strongly Encapsulate JDK Internals by Default

  • Strongly encapsulate all internal elements of the JDK past default, except for critical internal APIs such as dominicus.misc.Unsafe. Allow end users to choose the relaxed strong encapsulation that has been the default since JDK 9.
  • With this change, the default value of the launcher option --illegal-access is now deny rather than let. As a consequence, existing code that uses most internal classes, methods, or fields of the JDK volition neglect to run. Such code tin be made to run on JDK sixteen past specifying --illegal-access=let. That option volition, still, be removed in a future release.

JEP 393: Foreign-Memory Access API (Third Incubator)

  • Innovate an API to allow Java programs to safely and efficiently access foreign retentiveness outside of the Coffee heap.

JEP 390: Warnings for Value-based Classes

  • Users of the value-based classes provided by the standard libraries---notably including users of the primitive wrapper classes---should avert relying on the identity of class instances. Programmers are strongly discouraged from calling the wrapper grade constructors, which are now deprecated for removal. New javac warnings discourage synchronization on value-based course instances. Runtime warnings almost synchronization can also be activated, using control-line pick -20:DiagnoseSyncOnValueBasedClasses.

Complete release notes here.