Checked-exception-enabled Java functional interfaces — a zero-dependency drop-in for java.util.function.
Java's java.util.function interfaces don't support checked exceptions, turning clean one-liners into verbose try-catch blocks:
// what you want
.map(path -> new URI(path))
// what Java forces you to write
.map(path -> {
try {
return new URI(path);
} catch (URISyntaxException e) {
throw new RuntimeException(e);
}
})throwing-function provides checked-exception-aware variants of all standard functional interfaces:
ThrowingFunction<String, URI, URISyntaxException> toUri = URI::new;And adapters to integrate them into standard Java APIs:
stream.map(ThrowingFunction.unchecked(URI::new))
.forEach(System.out::println);| Interface | Functional method |
|---|---|
ThrowingFunction<T, R, E> |
R apply(T t) throws E |
ThrowingBiFunction<T1, T2, R, E> |
R apply(T1 t1, T2 t2) throws E |
ThrowingUnaryOperator<T, E> |
T apply(T t) throws E |
ThrowingBinaryOperator<T, E> |
T apply(T t1, T t2) throws E |
ThrowingConsumer<T, E> |
void accept(T t) throws E |
ThrowingBiConsumer<T, U, E> |
void accept(T t, U u) throws E |
ThrowingSupplier<T, E> |
T get() throws E |
ThrowingPredicate<T, E> |
boolean test(T t) throws E |
ThrowingBiPredicate<T, U, E> |
boolean test(T t, U u) throws E |
ThrowingRunnable<E> |
void run() throws E |
ThrowingToLongFunction<T, E> |
long applyAsLong(T t) throws E |
Each interface provides static adapter methods to bridge Throwing* instances into standard java.util.function types.
Wraps the checked exception in a CheckedException (a RuntimeException subclass) and rethrows it. Available on all interfaces.
stream.map(ThrowingFunction.unchecked(URI::new))
.forEach(System.out::println);Rethrows the checked exception as-is, bypassing the compiler's checked-exception enforcement via type erasure. Available on all interfaces.
stream.map(ThrowingFunction.sneaky(URI::new))
.forEach(System.out::println);Returns the result wrapped in an Optional, or Optional.empty() on exception. No exception is propagated.
ThrowingFunction.lifted(f)→Function<T, Optional<R>>ThrowingBiFunction.optional(f)→BiFunction<T1, T2, Optional<R>>ThrowingSupplier.optional(s)→Supplier<Optional<T>>
stream.map(ThrowingFunction.lifted(URI::new)) // Stream<Optional<URI>>
.forEach(System.out::println);<dependency>
<groupId>com.pivovarit</groupId>
<artifactId>throwing-function</artifactId>
<version>1.6.1</version>
</dependency>implementation 'com.pivovarit:throwing-function:1.6.1'- bbottema/simple-java-mail — Simple Java Mail, one of the most widely used Jakarta Mail / SMTP wrappers in the Java ecosystem.
None. Implemented using core Java libraries only.