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JavaSpecialists

Issue 338 - Adjusting Number of Carrier Threads Dynamically

Java 24 added the VirtualThreadSchedulerMXBean, which gives us insight into the pool that is executing our virtual threads. We can even change the number of carrier threads at runtime. In this newsletter we discover how this can get us out of a pickle.

Issue 337 - Module Imports

Module imports are a new feature in Java 25 and are like a wildcard import for *all* the types in a module. If you hate wildcard imports, you'll despise this even more. But if, like me, you don't really care whether someone uses a wildcard or single-type import, this is for you.

Issue 336 - CopyOnWriteArrayList.subList() ConcurrentModificationException

Java's CopyOnWriteArrayList gives us a snapshot iterator for fast reading. However, its subList() is not snapshot, and will break if the list is changed. In this newsletter we look at a way to make a safe subList() copy, using the iterator and an AbstractList.

Issue 335 - ZGC Mysteries

In our previous newsletter we posted a puzzle about ArrayList creation in ZGC. Lots of Java programmers sent in their ideas, and we are still looking for the perfect answer. Here are some more thoughts on the idea, whilst we wait for The Z Garbage Collector Book to arrive.

Issue 334 - ArrayList vs LinkedList Puzzle

Every schoolboy knows that arrays are faster than linked structures, no matter the language. In this newsletter we present a puzzle where we find LinkedList outperforming ArrayList for ZGC. Let's see who comes up with the most thorough explanation why.


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Blog Posts

What is vibe coding?

Posted by Michael Levin on June 9, 2025 at 9:37am 0 Comments

Vibe coding isn’t a formal technical term, but it’s become a slang or colloquial expression among programmers and tech communities—especially on social media and in creative coding circles.

What “vibe coding” usually means:

  1. Coding based on intuition or feel

    Instead of rigidly planning everything out, you’re:

    • Freestyling as you…
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JavaFX and SteelSeries gauges using FXML

Posted by Jim Clarke on June 25, 2012 at 9:30pm 0 Comments

Gerrit Grunwald, aka @hansolo_ on twitter, has just ported his Swing based gauges and meters framework known as SteelSeries to JavaFX as part of the JFXtras-lab project. I can't tell you how many times since Java AWT first came out, that I have had to use meters…

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Ceylon OJUG & GatorJUG Talk - Please Yo me!

Posted by Michael Levin on June 27, 2014 at 11:15am 4 Comments

Dear Codetown JUGGIES:

We have a chance for a special Ceylon talk on either Mon 10/13, Fri 10/17, Mon 10/20, or Fri 10/24 in Orlando at OrlandoJUG and/or Gainesville at GatorJUG. 

As you all know, OJUG meets 4th Th and GatorJUG meets 2nd Wed and these are Mondays and Fridays, so I need your…

Continue

What's bit.ly?

Posted by Michael Levin on March 22, 2009 at 12:00pm 0 Comments

On the surface, bit.ly appears to be a tinyurl.com clone. But, bit.ly has a powerful API so you can use it in your websites. It also has semantic capability and uses Amazon S3 to store your data. It's GeoSpatially enabled, which raises all sorts of possibilities. Think iPhone apps - especially with iPhone 3G's GPS capability. Here's a good… Continue

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Java books for any library 5 Replies

What books should be on the bookshelf of EVERY Java programmer, no matter what specific technologies they are working on?The two that come to my mind areThinking in JavaJava Concurrency in PracticeWhat else am I missing?Continue

Started by David Moskowitz in Java. Last reply by sneha gulati Feb 8, 2019.

Error trying to use Fragment

I am new to Android.  I have been working thru some examples in a book called  Head First Android Development.  I entered a small program using fragments and get a Casting Error.cannot cast andoid.app.fragment to…Continue

Tags: Fragment

Started by Robert Sobol in Java Oct 10, 2017.

Fragment Syntax Problem

My name is Rob Sobol.I have been working through a book called Head First Android Development.I hit a syntax error in a simple exercise that uses one fragment. I have been trying to figure out the error for days.  I am hoping some in the forum can…Continue

Tags: Fragments

Started by Robert Sobol in Java Oct 10, 2017.

Hadoop getting old?

An article just came out in InfoWorld about trends, which is always an interesting subject. Funny, they said Hadoop wasn't hot. Spark is. It's a good read. …Continue

Tags: codetown, infoworld, programming, hadoop, trends

Started by Michael Levin in Trends Apr 10, 2017.

What's functional programming, anyway?

Can you believe people are still trying to come up with a good definition or explanation of what functional programming is? Paul Krill is a journalist with InfoWorld. Here's an article he just wrote: …Continue

Tags: functions., codetown, lambdas, clojure, programming

Started by Michael Levin in Functional Programming Feb 21, 2016.

Santafe College 2 Replies

Santafe just added a new BAS  bachelor's program of study. 5651  ProgrammingContinue

Started by Dan Lackey in Dynamic Languages. Last reply by Michael Levin Feb 15, 2016.

Using SQL with Node,.js 1 Reply

All the tutorials and books for node.js seem to use Mongo as the database.  I am not sold on 'document' databases and would like to know how difficult it is to use any version for plain old tried-and-true SQL with Node.js.Does anybody have any…Continue

Tags: 'document, databases', SQL, node, node.js

Started by Kevin Neelands in Dynamic Languages. Last reply by Lou Caudell Nov 10, 2015.

The advantages of a RESTfull web-based API 5 Replies

I need to get a better handle on the advantages of a RESTful web-based API.  People tell me they scale better than other methods, but I don't see how they reduce database access or have any other feature that helps handle large amounts of traffic.…Continue

Tags: API', 'web-based, RESTful

Started by Kevin Neelands in Dynamic Languages. Last reply by Kevin Neelands Oct 25, 2015.

Want a Job? 1 Reply

Hi, Not sure if this is the appropriate place to post this sort of things (forgive me if its not). My company (really nice company btw) is looking to hire two junior and two senior Java Developers. Please forward me your resume to slaassel@gmail.com…Continue

Started by Saad Laassel in Java. Last reply by Theresa Wizorek-MacIntyre Oct 15, 2014.

Storing Sensitive Data ( like SSNs ) 1 Reply

We might have to store Social Security Numbers.  We REALLY don't want to do this in our own database, we'd like some external 'vault' service that stores them encrypted and getting to them is difficult.  Does anyone have any ideas along these lines?Continue

Started by Kevin Neelands in Java. Last reply by Michael Levin May 7, 2014.

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I recently read an article describing how to pair an Apple Watch with an iPhone. Looks great. You can leave your iPhone someplace and then use your Apple Watch as a phone. I don’t know anything about Apple watches, but they have them at Costco and of course at the Apple Store. What’s the latest, best one to get And Ann what do you know about this idea?…See More
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I recently read an article describing how to pair an Apple Watch with an iPhone. Looks great. You can leave your iPhone someplace and then use your Apple Watch as a phone. I don’t know anything about Apple watches, but they have them at Costco and of course at the Apple Store. What’s the latest, best one to get And Ann what do you know about this idea?…See More
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Notes

Welcome to Codetown!

Codetown is a social network. It's got blogs, forums, groups, personal pages and more! You might think of Codetown as a funky camper van with lots of compartments for your stuff and a great multimedia system, too! Best of all, Codetown has room for all of your friends.

When you create a profile for yourself you get a personal page automatically. That's where you can be creative and do your own thing. People who want to get to know you will click on your name or picture and…
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Created by Michael Levin Dec 18, 2008 at 6:56pm. Last updated by Michael Levin May 4, 2018.

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InfoQ Reading List

AWS Capacity Largely Sold Out Through 2027, With On Demand Headroom Reserved

Amazon CEO Andy Jassy says AWS’s large committed cloud capacity is largely sold out through 2027, with part of 2028 already allocated, while the company continues to reserve headroom for On Demand, EC2 and Bedrock. Practitioners discussing the remarks report difficulty obtaining On Demand capacity for ordinary EC2 instances, and similar constraints at other providers.

By Steef-Jan Wiggers

File Mover Express: AWS Releases Open-Source Tool for S3 File Transfers

AWS has recently released File Mover Express, an open-source application under the Apache 2.0 license for transferring large files between local systems and Amazon S3. Available for macOS, Windows, and Linux, it supports parallel transfers, automatic performance tuning, retries, pause and resume, and file integrity verification.

By Renato Losio

Cloudflare’s Post-Quantum GeoKey Manager Enters Closed Beta Without Attribute-Based Encryption

Cloudflare has moved a post-quantum rebuild of GeoKey Manager into closed beta, guarding geo-fenced keys with hybrid ML-KEM-768 and X25519 instead of the attribute-based encryption used since 2022. Keys live only in kernel memory on verified regional servers, and any failed check rejects the request, a fail-closed choice practitioners ask could cause a regional outage. GA is planned for Q1 2027.

By Steef-Jan Wiggers

OpenBSD 8.0 Brings Expanded Hardware Support, Security Enhancements, and Virtualization Improvements

OpenBSD 8.0 is a substantial upgrade bringing broader hardware compatibility, enhanced security, an expanded virtual address space, and support for modern architectures, including Intel Arc A-Series graphics support, ARM64 hibernation, RISC-V improvements, and enhanced virtual machine support.

By Sergio De Simone

Spring News Roundup: First Release Candidates of Boot, Framework, Data, Security, Modulith, AI

There was a flurry of activity during the week of October 19th, 2026, highlighting: first release candidates of: Spring Boot, Spring Framework, Spring Data, Spring Cloud, Spring Security, Spring for GraphQL, Spring Session, Spring Integration, Spring HATEOS, Spring Modulith, Spring REST Docs, Spring AI, Spring Batch, Spring AMQP, Spring for Apache Kafka, Spring LDAP and Spring Web Services.

By Michael Redlich

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