Tips, Expertise, Articles and Advice from the Pro's for Your Website or Blog to Succeed
I had the opportunity to talk to Aurelio Garcia-Ribeyro, Senior Director of Product Management at Oracle.
Two years ago I wrote an article about the concerns with Java. These included: quality, release cadence and fatigue, taking security seriously, Oracle's role as a steward of Java, and progress relative to other languages. I began the conversation by asking Aurelio about these issues.
On Monday, Mark Reinhold's post "JEPs proposed to target JDK 14: 305, 343, 359, 366, & 368" proposed targeting five more JEPs to JDK 14. Some highly anticipated features are among this group, although all but one are proposed to be in "preview" or "incubating":
instanceof (Preview)The Java SE 13 Java Language Updates document describes preview features (JEP 12): "A preview feature is a new feature whose design, specification, and implementation are complete, but which is not permanent, which means that the feature may exist in a different form or not at all in future JDK releases."
A recent Mark Reinhold message announces six new "JEPs proposed to target JDK 14": JEP 345, JEP 361, JEP 363, JEP 364, JEP 365, and JEP 367. Assuming no objections are made by November 7, these JEPs will be targeted to JDK 14 along with previously targeted JEPs JEP 349 ("JFR Event Streaming"), JEP 352 ("Non-Volatile Mapped Byte Buffers"), and JEP 358 (" Helpful NullPointerExceptions"). This post summarizes each of these six JEPs proposed for targeting JDK 14.
The succinct "Summary" of JEP 345 states, "Improve G1 performance on large machines by implementing NUMA-aware memory allocation." Two important "non-goals" of this JEP indicate that the JEP is only intended to add NUMA (non-uniform memory access) support to the G1 garbage collector and only for Linux. However, the JEP also points out that "the parallel collector, enabled by -XX:+UseParallelGC, has been NUMA-aware for many years."
The latest JEP 359 outlines a new Java feature that may/will be implemented in some future versions of Java. The JEP suggests having a new type of "class": record.
You may also like: Java Records: Making Bad Designs More Convenient
The sample in the JEP reads as follows:
Following the recent announcement of the candidate JEP on sealed types (preview), Gavin Bierman's message "Draft JLS spec for sealed types" on the OpenJDK amber-spec-experts mailing list announces "a draft language spec for sealed types" and provides a link to that draft. That message also states: "This spec doesn't yet contain details on binary compatibility (Chapter 13) — to appear in the next draft."
You may also like: Candidate JEPs: Records and Sealed Types
In this post, I highlight some of the proposed changes to the Java Language Specification (JLS) for sealed types. It is important to keep in mind the tentativeness of these proposed changes: this is an of JLS changes for a feature associated with a JDK Enhancement Proposal (JEP).
Mark Reinhold announced two new closely related candidate JDK Enhancement Proposals (JEPs) on the OpenJDK amber-dev mailing list this week with the posts "New candidate JEP: 359: Records (Preview)" and " New candidate JEP: 360: Sealed Types (Preview)." Both of these candidate JEPs are "preview features" (defined by JEP 12).
In other JDK news: java.lang.Records: Draft Specification
The JEP 359 "Summary" states, "Enhance the Java programming language with records. Records provide a compact syntax for declaring classes which are transparent holders for shallowly immutable data."
JEP 280 ("Indify String Concatenation") was implemented in conjunction with JDK 9 and, according to its "Summary" section, "Change[s] the static String-concatenation bytecode sequence generated by javac to use invokedynamic calls to JDK library functions." The impact this has on string concatenation in Java is most easily seen by looking at the javap output of classes using string concatenation that is compiled in pre-JDK 9 and post-JDK 9 JDKs.
The following simple Java class named "HelloWorldStringConcat" will be used for the first demonstration.