Codetown

Issue 296 - Concurrent LinkedHashSet

LinkedHashSet is a set that can also maintain order. To make this thread-safe, we can wrap it with Collections.synchronizedSet(). However, this is not a good option, because iteration would still be fast-fail. And what's the point of a thread-safe LinkedHashSet that we cannot iterate over? In this newsletter we try to create a concurrent set that behaves like a LinkedHashSet, but with minimal locking and with a weakly-consistent iteration.

Issue 295 - Faster Empty Streams

Streams can make our code more readable, and therefore more maintainable. However, there is some overhead in setting up the stream, a cost that might become pronounced when the stream is empty. In this newsletter we will consider an idea of the EmptyStream to reduce that cost.

Issue 294 - String.format() 3x faster in Java 17

One of the most convenient ways of constructing complex Strings is with String.format(). It used to be excessively slow, but in Java 17 is about 3x faster. In this newsletter we discover what the difference is and where it will help you. Also when you should use format() instead of the plain String addition with +.

Issue 293 - Canonical Orders

Should we write "public abstract static class" or "public static abstract class"? And should fields be "final static private" or "private static final"? In this newsletter we explore the canonical order of modifiers in Java.

Issue 292 - StartingGun Synchronizer

CountDownLatch is easy to understand, but can be hard to use, especially the await() method that throws InterruptedException. In this newsletter we show how we can create our own synchronizer based on the AbstractQueuedSynchronizer.