The new features coming to Java 13 – JDK 13
While the Open JDK reference webpage for Java Development Kit (JDK) 13 doesn't yet list any new options, a couple of proposals are said to be targeted for the release.
JDK 13 is due 17th September 2019 following ramp down and unharness candidate stages occurring in coming back months. JDK improvement Proposals eyed for the discharge cover:
Development a tool for packaging self contained Java applications known as Jpackage. The tool would be supported the JavaFX javapackagertool that supports native packaging formats to offer the user a natural installation expertise. It permits launch-time parameters to be specified at packaging time. The tool is invoked directly from the statement or programmatically via the ToolProvider. Several applications need to be installed on a native platform in an exceedingly “first-class” approach instead of being placed on the class path or module path. A packaging tool can also fill gaps left by technologies like Java web start, which was removed from Oracle’s JDK 11. The javapackagertool was deleted from JDK 11 as a part of the removal of JavaFX.
Enhancing the ZGC (Z Garbage Collector) to come back unused memory to the OS, a proposal cited as integrated into JDK 13. ZGC, that is beaked as a scalable, low-latency collector, presently doesn't return unused memory back to the OS even if the memory has not been used in an extended time. This behavior isn't optimum for a few applications environments, particularly those where memory footprint could be a concern, like containers or environments wherever an application might be idle for an extended time and is sharing or competitive for resources with alternative applications.
Extending Application Class Data Sharing (AppCDS) to modify dynamic archiving of classes at the end of application execution. Archived classes would come with all loaded application and library classes not present within the default, base-layer CDS archive. This proposal, which is within the targeted stage, is meant to enhance the usability of AppCDS and eliminate the necessity for users to try and do trial runs to form a category list for every application.
Two capabilities anticipated for JDK 13 are cited antecedently by Mark Reinhold, chief designer of the Java platform cluster at Oracle:
Raw string literals, which may span multiple lines of source code and don't interpret, escape sequences. This capability had been cut from JDK 12, which arrived in March 2019. The arrangement is to supply raw string literals solely as an opt-in beta in JDK 13. Its goal is to form development easier n Java by, for instance, letting developers express sequences of characters in a readable kind free of Java indicators, or offer strings targeted for grammars apart from Java. Following the expected take a look at run in JDK 13, raw string literals may be created production-quality within the future JDK 14 unleashes.
A production version of switch expressions, that JDK can provide a beta implementation. The switch statement are extended to be used as either a statement or an expression, thus each may use either a “traditional” or “simplified” scoping and control flow behavior.