Everything You Ever Wanted to Know About Java and Didn’t Know Whom to Ask 

Speakers: Everyone 🙂

For more blog posts, see The Oracle Code One table of contents

Q&A

• What is the best way to get a new method/feature into Java?
  • Discuss, open JEP, debate. Search Thread.onSpinWait() for an example
  • Discussion first is important. Starts discussion about problem. The code provided isn’t always the best way to solve it.
  • The thing that ends up happening is not what you started with
• How to integrate collection PL/SQL in Java?
  • <missed answer>
• Why is TreeMap implemented as a red black tree?
  • best/only way to do it
  • balanced tree
• Is Java too slow?
  • Always want faster
  • Not too slow for a language with a statically compiled language
  • Tune for use case
  • Java will work faster on CPU don’t have yet. JIT compilers will optimize for it.
• Is String interpolation coming?
  • Java 12 “briefly” had raw string literals
  • Recognize sprint interpolation is valuable
  • Need to figure out a way to do cleanly
  • Need to get multi line done. Then escape sequences. Then string interpolation
• How move past Java 8?
  • Business and technical question
  • First step: will it compile/run
  • Don’t need to rewrite everything with new features
  • Business might not want to spend money on technical problem
  • A handful of people have only Java 11 in prod. Many people have one app/POC in prod. A lot of people only Java 8.
  • Java 9 and 10 is irrelevant. Nobody supports. Binaries not rebuilt with security updates.
  • The technical challenges are libraries that used Unsafe or assumed version strings begin with 1.x.
  • Evangelism message: upgrading to a higher version of Java is just like upgrading to a later version of 8.
  • Counterpoint: People have jars that don’t run on 11.
  • Sometimes features or APIs are removed.
• How do you look at OSGi?
  • Nobody does anymore
• Are you happy with the new release cycle?
  • Bruno interviewed Brian Goetz who said he was skeptical at first, but now done four times and smooth.
  • Java 13 came out this week. Brian was at Code One. Not managing process. No longer have months of meetings about release.
• Deprecate serialization?
  • No plans
  • Many problems.
  • There is a need for something like serialization.
  • Brian wrote up ideas: http://cr.openjdk.java.net/~briangoetz/amber/serialization.html (Not a proposal for replacing serialization)
• How do we keep up with six month releases?
  • Try when come out.
  • We know when they come out
  • Not a lot will break if do each time
  • Counterpoint: Play on laptop, but don’t use features until LTS comes out. If using 12.0.2 and security issue, you have to run 13 when it is 3 weeks old. Going to prod on feature release is risky.
• Real tuples in Java?
  • Proposal for records in Java
• Is it possible to break a nested loop in Java?
  • Yes with labels. [but please don’t].
• Fixing exception handling on lambdas
  • Aware of issues
  • Not convenient to deal with
  • Ideas, but no current plans
• Map on how to choose a JDK for a given use case
  • AdoptOpenJDK and Java Champions discussing how to create that map
• New features we are looking forward to
  • Value types
  • Pattern matching
  • Generic specialization
• How long will Unsafe be around
  • However long it takes to pull out all the useful features
  • ex: Java 9 var handles
  • Will take years
• Low level libraries that are useful
  • ASM
  • Byte Buddy
• Type extraction on return values
  • Return a tuple and set to multiple variables
  • “Let’s compare Java to Kotlin”
  • Could write something like it with pattern matching
• Why are Strings in Java harder than other languages?
  • Strings have evolved
  • Unsolved problem
  • Changed a lot underneath
  • String concatenation now performed by invoke dynamic

My take

I like how he accepted questions both verbally and via Twitter. The variety of questions was fun. I like that Gil asked the “who is on Java 11” question well. He asked granularly enough to answer honestly and realistically. Stuart did a great job with his Dr Deprecator character when there was discussion about APIs being removed.