throwing-function

Checked Exceptions-enabled Java 8+ functional interfaces + adapters

Provides shortcuts for solving Java 8 checked exceptions lambda repackaging hell.

You can define functions that throw checked exceptions:

ThrowingFunction<String, URI, URISyntaxException> toUri = URI::new;

And use those functions seamlessly with native `java.util.function` classes by using a custom `ThrowingFunction#unchecked` adapter:

...stream()
  .map(unchecked(URI::new)) // static import of ThrowingFunction#unchecked
  .forEach(System.out::println);

No more:

 ...stream().map(path -> {
     try {
         return new URI(path);
     } catch (URISyntaxException e) {
         throw new RuntimeException(e);
     }}).forEach(System.out::println);

For Maven users:

<dependency>
    <groupId>pl.touk</groupId>
    <artifactId>throwing-function</artifactId>
    <version>1.3</version>
</dependency>

For Gradle users:

compile 'pl.touk:throwing-function:1.3'

Available types:

ThrowingBiConsumer
ThrowingBiFunction
ThrowingBiPredicate
ThrowingBinaryOperator
ThrowingConsumer
ThrowingFunction
ThrowingPredicate
ThrowingRunnable
ThrowingSupplier
ThrowingUnaryOperator

Additional features:

default Function<T, R> uncheck() {...}

Transforms a ThrowingFunction instance into a regular Function. Checked exceptions get wrapped in a RuntimeException. Feature is available for all java.util.function types. Comes both as a static and as an instance method.

static Function<T, R> uncheck(ThrowingFunction<> f) {...}

Static version of the uncheck() method. Works nice when using with original java functional types. ...stream().map(unchecked(URI::new)).forEach(System.out::println);

static Function<T, Optional<R>> lifted() {...}

Transforms ThrowingFunction into a regular Function returning result wrapped into an Optional instance. If exception is thrown, result will contain an empty Optional instance. Exception gets ignored. Comes as a static method. Equivalent instance method is called lift()

default ThrowingFunction<T, Void, E> asFunction() {...}

Returns ThrowingPredicate/ThrowingSupplier/ThrowingConsumer instance as a new ThrowingFunction instance.

Checker.checked()

Additional static function allowing catching wrapped checked exceptions, unwrap and rethrow them. Comes in handy sometimes.

dkapil/throwing-function