SneakyThrow   🥷

This sneaky caretaker has to be taken with care. It makes checked exceptions behave like runtime exceptions, by making them generic. This bypasses the Java compiler and is perfectly allowed within the JVM, which doesn't even know about checked exceptions.

The trick is done by turning the common java functions such as Consumer, Function, Supplier, ... into throwing ones. These throwing ones are just sub interfaces of the originals, so the original superclass is then returned. The throwing method is then caught and the exception is thrown genericly.

The problem is now that everything is fine, but you know it may possibly throw an IOException. So in this case, it's advisable to have your method throw IOException too. It hands over resposibility to the caller of your method and everything is checked again.

It just comes in real handy when working with streams, but always remember that you're just hiding exceptions you would otherwise had to handle. And it's better to throw these exact exceptions, than to just throw a new RuntimeException(e) out of lazyness. It keeps the code clean, but it requires responsibility.

💡 Tip: Use static import.

sneaky

The sneaky method turns a java.util functions into throwing ones. An overview of those throwing functions is found below.

stream.forEach(SneakyThrow.sneaky(Files::readAllBytes));

throwSneaky

This method takes an Exception as argument and throws it generically. throwSneaky itself does nothing more than throwing the provided Exception as a generic one (<E extends Throwable>).

This will obfuscate the checked Exception, so that it gets treated as being a runtime Exception.

SneakyThrow.throwSneaky(new IOException());

Functions

ThrowingFunction

A java.util.Function which throws an Exception.

ThrowingBiFunction

A java.util.BiFunction which throws an Exception.

ThrowingConsumer

A java.util.Consumer which throws an Exception.

ThrowingBiConsumer

A java.util.BiConsumer which throws an Exception.

ThrowingSupplier

A java.util.Supplier which throws an Exception.

ThrowingPredicate

A java.util.Predicate which throws an Exception.