I got a lot of interesting feedback on Checked exceptions and lambdas. Let’s start with my own: after writing the post, I realized I had written a similar post some time ago. Mistakes I made I made a mistake in the code regarding Apache Commons Lang 3, where I mistakenly used the recover() function, which is actually from Vavr. Apache Commons Lang provides a regular utility function, which mimics the custom code we wrote last week.

Java’s checked exceptions were a massive improvement over C’s error-handling mechanism. As time passed and experience accumulated, we collectively concluded that we weren’t there yet. However, Java’s focus on stability has kept checked exceptions in its existing API. Java 8 brought lambdas after the 'checked exceptions are great' trend. None of the functional interface methods accepts a checked exception.

Java introduced the concept of checked exceptions. The idea of forcing developers to manage exceptions was revolutionary compared to the earlier approaches. Nowadays, Java remains the only widespread language to offer checked exceptions. For example, every exception in Kotlin is unchecked. Even in Java, new features are at odds with checked exceptions: the signature of Java’s built-in functional interfaces doesn’t use exceptions.