Try (Javaslang 2.0.0 API)

Type Parameters:

T - Value type in the case of success.

All Superinterfaces:

Iterable<T>, Value<T>

All Known Implementing Classes:

Try.Failure, Try.Success
```
public interface Try<T>
extends Value<T>
```
An implementation similar to Scala's Try control.

Since:

1.0.0

Author:

Daniel Dietrich

Nested Class Summary

Nested Classes
Modifier and Type	Interface and Description
`static interface`	`Try.CheckedConsumer<T>` A Consumer which may throw.
`static interface`	`Try.CheckedFunction<T,R>` A Function which may throw.
`static interface`	`Try.CheckedPredicate<T>` A Predicate which may throw.
`static interface`	`Try.CheckedRunnable` A Runnable which may throw.
`static interface`	`Try.CheckedSupplier<R>` A Supplier which may throw.
`static class`	`Try.Failure<T>` A failed Try.
`static class`	`Try.FatalException` An unchecked wrapper for Fatal exceptions.
`static class`	`Try.NonFatalException` An unchecked wrapper for non-fatal/recoverable exceptions.
`static class`	`Try.Success<T>` A succeeded Try.

Method Summary

All Methods Static Methods Instance Methods Abstract Methods Default Methods
Modifier and Type	Method and Description
`default Try<T>`	`andThen(Consumer<? super T> consumer)` Shortcut for `andThenTry(consumer::accept)`, see `andThenTry(CheckedConsumer)`.
`default Try<T>`	`andThen(Runnable runnable)` Shortcut for `andThenTry(runnable::run)`, see `andThenTry(CheckedRunnable)`.
`default Try<T>`	`andThenTry(Try.CheckedConsumer<? super T> consumer)` Passes the result to the given `consumer` if this is a `Success`.
`default Try<T>`	`andThenTry(Try.CheckedRunnable runnable)` Runs the given runnable if this is a `Success`, otherwise returns this `Failure`.
`boolean`	`equals(Object o)` Clarifies that values have a proper equals() method implemented.
`default Try<Throwable>`	`failed()` Returns `Success(throwable)` if this is a `Failure(throwable)`, otherwise a `Failure(new NoSuchElementException("Success.failed()"))` if this is a Success.
`static <T> Try<T>`	`failure(Throwable exception)` Creates a `Try.Failure` that contains the given `exception`.
`default Try<T>`	`filter(Predicate<? super T> predicate)` Shortcut for `filterTry(predicate::test)`, see `filterTry(CheckedPredicate)`}.
`default Try<T>`	`filterTry(Try.CheckedPredicate<? super T> predicate)` Returns `this` if this is a Failure or this is a Success and the value satisfies the predicate.
`default <U> Try<U>`	`flatMap(Function<? super T,? extends Try<? extends U>> mapper)` Shortcut for `flatMapTry(mapper::apply)`, see `flatMapTry(CheckedFunction)`.
`default <U> Try<U>`	`flatMapTry(Try.CheckedFunction<? super T,? extends Try<? extends U>> mapper)` FlatMaps the value of a Success or returns a Failure.
`T`	`get()` Gets the result of this Try if this is a Success or throws if this is a Failure.
`Throwable`	`getCause()` Gets the cause if this is a Failure or throws if this is a Success.
`default T`	`getOrElseGet(Function<? super Throwable,? extends T> other)`
`default <X extends Throwable> T`	`getOrElseThrow(Function<? super Throwable,X> exceptionProvider)`
`int`	`hashCode()` Clarifies that values have a proper hashCode() method implemented.
`boolean`	`isEmpty()` Checks whether this Try has no result, i.e.
`boolean`	`isFailure()` Checks if this is a Failure.
`default boolean`	`isSingleValued()` A `Try` is a single-valued.
`boolean`	`isSuccess()` Checks if this is a Success.
`default Iterator<T>`	`iterator()` Returns a rich `javaslang.collection.Iterator`.
`default <U> Try<U>`	`map(Function<? super T,? extends U> mapper)` Shortcut for `mapTry(mapper::apply)`, see `mapTry(CheckedFunction)`.
`default <U> Try<U>`	`mapTry(Try.CheckedFunction<? super T,? extends U> mapper)` Runs the given checked function if this is a `Success`, passing the result of the current expression to it.
`static <T> Try<T>`	`narrow(Try<? extends T> t)` Narrows a widened `Try<? extends T>` to `Try<T>` by performing a type safe-cast.
`static <T> Try<T>`	`of(Try.CheckedSupplier<? extends T> supplier)` Creates a Try of a CheckedSupplier.
`default Try<T>`	`onFailure(Consumer<? super Throwable> action)` Consumes the throwable if this is a Failure.
`default Try<T>`	`onSuccess(Consumer<? super T> action)` Consumes the value if this is a Success.
`default Try<T>`	`orElse(Supplier<? extends Try<? extends T>> supplier)`
`default Try<T>`	`orElse(Try<? extends T> other)`
`default void`	`orElseRun(Consumer<? super Throwable> action)`
`default Try<T>`	`peek(Consumer<? super T> action)` Applies the action to the value of a Success or does nothing in the case of a Failure.
`default Try<T>`	`recover(Function<? super Throwable,? extends T> f)` Returns `this`, if this is a `Success`, otherwise tries to recover the exception of the failure with `f`, i.e.
`default Try<T>`	`recoverWith(Function<? super Throwable,? extends Try<? extends T>> f)` Returns `this`, if this is a Success, otherwise tries to recover the exception of the failure with `f`, i.e.
`static Try<Void>`	`run(Try.CheckedRunnable runnable)` Creates a Try of a CheckedRunnable.
`static <T> Try<Seq<T>>`	`sequence(Iterable<? extends Try<? extends T>> values)` Reduces many `Try`s into a single `Try` by transforming an `Iterable<Try<? extends T>>` into a `Try<Seq<T>>`.
`static <T> Try<T>`	`success(T value)` Creates a `Try.Success` that contains the given `value`.
`default Either<Throwable,T>`	`toEither()` Converts this `Try` to an `Either`.
`String`	`toString()` Clarifies that values have a proper toString() method implemented.
`default <U> U`	`transform(Function<? super Try<T>,? extends U> f)` Transforms this `Try`.

Methods inherited from interface javaslang.Value
contains, corresponds, eq, exists, forAll, forEach, getOption, getOrElse, getOrElse, getOrElseThrow, getOrElseTry, narrow, out, out, stderr, stdout, stringPrefix, toArray, toCharSeq, toJavaArray, toJavaArray, toJavaCollection, toJavaList, toJavaList, toJavaMap, toJavaMap, toJavaOptional, toJavaSet, toJavaSet, toJavaStream, toLeft, toLeft, toList, toMap, toOption, toQueue, toRight, toRight, toSet, toStack, toStream, toTree, toTry, toTry, toVector

Methods inherited from interface java.lang.Iterable
spliterator

- Method Detail
 - of
```
static <T> Try<T> of(Try.CheckedSupplier<? extends T> supplier)
```
 Creates a Try of a CheckedSupplier.
 
 Type Parameters:
 
 T - Component type
 
 Parameters:
 
 supplier - A checked supplier
 
 Returns:
 
 Success(supplier.get()) if no exception occurs, otherwise Failure(throwable) if an exception occurs calling supplier.get().
 - run
```
static Try<Void> run(Try.CheckedRunnable runnable)
```
 Creates a Try of a CheckedRunnable.
 
 Parameters:
 
 runnable - A checked runnable
 
 Returns:
 
 Success(null) if no exception occurs, otherwise Failure(throwable) if an exception occurs calling runnable.run().
 - sequence
```
static <T> Try<Seq<T>> sequence(Iterable<? extends Try<? extends T>> values)
```
 Reduces many Trys into a single Try by transforming an Iterable<Try<? extends T>> into a Try<Seq<T>>. If any of the Trys are Try.Failure, then this returns a Try.Failure.
 
 Type Parameters:
 
 T - type of the Trys
 
 Parameters:
 
 values - An Iterable of Trys
 
 Returns:
 
 A Try of a Seq of results
 
 Throws:
 
 NullPointerException - if values is null
 - success
```
static <T> Try<T> success(T value)
```
 Creates a Try.Success that contains the given value. Shortcut for new Success<>(value).
 
 Type Parameters:
 
 T - Type of the given value.
 
 Parameters:
 
 value - A value.
 
 Returns:
 
 A new Success.
 - failure
```
static <T> Try<T> failure(Throwable exception)
```
 Creates a Try.Failure that contains the given exception. Shortcut for new Failure<>(exception).
 
 Type Parameters:
 
 T - Component type of the Try.
 
 Parameters:
 
 exception - An exception.
 
 Returns:
 
 A new Failure.
 - narrow
```
static <T> Try<T> narrow(Try<? extends T> t)
```
 Narrows a widened Try<? extends T> to Try<T> by performing a type safe-cast. This is eligible because immutable/read-only collections are covariant.
 
 Type Parameters:
 
 T - Component type of the Try.
 
 Parameters:
 
 t - A Try.
 
 Returns:
 
 the given t instance as narrowed type Try<T>.
 - andThen
```
default Try<T> andThen(Consumer<? super T> consumer)
```
 Shortcut for andThenTry(consumer::accept), see andThenTry(CheckedConsumer).
 
 Parameters:
 
 consumer - A consumer
 
 Returns:
 
 this Try if this is a Failure or the consumer succeeded, otherwise the Failure of the consumption.
 
 Throws:
 
 NullPointerException - if consumer is null
 - andThenTry
```
default Try<T> andThenTry(Try.CheckedConsumer<? super T> consumer)
```
 Passes the result to the given consumer if this is a Success.
 The main use case is chaining checked functions using method references:
```
 
 Try.of(() -> 100)
 .andThen(i -> System.out.println(i));

 
 
```
 Parameters:
 
 consumer - A checked consumer
 
 Returns:
 
 this Try if this is a Failure or the consumer succeeded, otherwise the Failure of the consumption.
 
 Throws:
 
 NullPointerException - if consumer is null
 - andThen
```
default Try<T> andThen(Runnable runnable)
```
 Shortcut for andThenTry(runnable::run), see andThenTry(CheckedRunnable).
 
 Parameters:
 
 runnable - A runnable
 
 Returns:
 
 this Try if this is a Failure or the runnable succeeded, otherwise the Failure of the run.
 
 Throws:
 
 NullPointerException - if runnable is null
 - andThenTry
```
default Try<T> andThenTry(Try.CheckedRunnable runnable)
```
 Runs the given runnable if this is a Success, otherwise returns this Failure.
 The main use case is chaining runnables using method references:
```
 
 Try.run(A::methodRef).andThen(B::methodRef).andThen(C::methodRef);
 
 
```
 Please note that these lines are semantically the same:
```
 
 Try.run(this::doStuff)
 .andThen(this::doMoreStuff)
 .andThen(this::doEvenMoreStuff);

 Try.run(() -> {
 doStuff();
 doMoreStuff();
 doEvenMoreStuff();
 });
 
 
```
 Parameters:
 
 runnable - A checked runnable
 
 Returns:
 
 this Try if this is a Failure or the runnable succeeded, otherwise the Failure of the run.
 
 Throws:
 
 NullPointerException - if runnable is null
 - failed
```
default Try<Throwable> failed()
```
 Returns Success(throwable) if this is a Failure(throwable), otherwise a Failure(new NoSuchElementException("Success.failed()")) if this is a Success.
 
 Returns:
 
 a new Try
 - filter
```
default Try<T> filter(Predicate<? super T> predicate)
```
 Shortcut for filterTry(predicate::test), see filterTry(CheckedPredicate)}.
 
 Parameters:
 
 predicate - A predicate
 
 Returns:
 
 a Try instance
 
 Throws:
 
 NullPointerException - if predicate is null
 - filterTry
```
default Try<T> filterTry(Try.CheckedPredicate<? super T> predicate)
```
 Returns this if this is a Failure or this is a Success and the value satisfies the predicate.
 Returns a new Failure, if this is a Success and the value does not satisfy the Predicate or an exception occurs testing the predicate.
 
 Parameters:
 
 predicate - A checked predicate
 
 Returns:
 
 a Try instance
 
 Throws:
 
 NullPointerException - if predicate is null
 - flatMap
```
default  Try flatMap(Function<? super T,? extends Try<? extends U>> mapper)
```
 Shortcut for flatMapTry(mapper::apply), see flatMapTry(CheckedFunction).
 
 Type Parameters:
 
 U - The new component type
 
 Parameters:
 
 mapper - A mapper
 
 Returns:
 
 a Try
 
 Throws:
 
 NullPointerException - if mapper is null
 - flatMapTry
```
default  Try flatMapTry(Try.CheckedFunction<? super T,? extends Try<? extends U>> mapper)
```
 FlatMaps the value of a Success or returns a Failure.
 
 Type Parameters:
 
 U - The new component type
 
 Parameters:
 
 mapper - A mapper
 
 Returns:
 
 a Try
 
 Throws:
 
 NullPointerException - if mapper is null
 - get
```
T get()
```
 Gets the result of this Try if this is a Success or throws if this is a Failure.
 
 Specified by:
 
 get in interface Value<T>
 
 Returns:
 
 The result of this Try.
 
 Throws:
 
 Try.NonFatalException - if this is a Failure
 - getCause
```
Throwable getCause()
```
 Gets the cause if this is a Failure or throws if this is a Success.
 
 Returns:
 
 The cause if this is a Failure
 
 Throws:
 
 UnsupportedOperationException - if this is a Success
 - isEmpty
```
boolean isEmpty()
```
 Checks whether this Try has no result, i.e. is a Failure.
 
 Specified by:
 
 isEmpty in interface Value<T>
 
 Returns:
 
 true if this is a Failure, returns false if this is a Success.
 - isFailure
```
boolean isFailure()
```
 Checks if this is a Failure.
 
 Returns:
 
 true, if this is a Failure, otherwise false, if this is a Success
 - isSingleValued
```
default boolean isSingleValued()
```
 A Try is a single-valued.
 
 Specified by:
 
 isSingleValued in interface Value<T>
 
 Returns:
 
 true
 - isSuccess
```
boolean isSuccess()
```
 Checks if this is a Success.
 
 Returns:
 
 true, if this is a Success, otherwise false, if this is a Failure
 - iterator
```
default Iterator<T> iterator()
```
 Description copied from interface: Value
 
 Returns a rich javaslang.collection.Iterator.
 
 Specified by:
 
 iterator in interface Iterable<T>
 
 Specified by:
 
 iterator in interface Value<T>
 
 Returns:
 
 A new Iterator
 - map
```
default  Try map(Function<? super T,? extends U> mapper)
```
 Shortcut for mapTry(mapper::apply), see mapTry(CheckedFunction).
 
 Specified by:
 
 map in interface Value<T>
 
 Type Parameters:
 
 U - The new component type
 
 Parameters:
 
 mapper - A checked function
 
 Returns:
 
 a Try
 
 Throws:
 
 NullPointerException - if mapper is null
 - mapTry
```
default  Try mapTry(Try.CheckedFunction<? super T,? extends U> mapper)
```
 Runs the given checked function if this is a Success, passing the result of the current expression to it. If this expression is a Failure then it'll return a new Failure of type R with the original exception. The main use case is chaining checked functions using method references:
```
 
 Try.of(() -> 0)
 .map(x -> 1 / x); // division by zero
 
 
```
 Type Parameters:
 
 U - The new component type
 
 Parameters:
 
 mapper - A checked function
 
 Returns:
 
 a Try
 
 Throws:
 
 NullPointerException - if mapper is null
 - onFailure
```
default Try<T> onFailure(Consumer<? super Throwable> action)
```
 Consumes the throwable if this is a Failure.
 
 Parameters:
 
 action - An exception consumer
 
 Returns:
 
 this
 
 Throws:
 
 NullPointerException - if action is null
 - onSuccess
```
default Try<T> onSuccess(Consumer<? super T> action)
```
 Consumes the value if this is a Success.
 
 Parameters:
 
 action - A value consumer
 
 Returns:
 
 this
 
 Throws:
 
 NullPointerException - if action is null
 - orElse
```
default Try<T> orElse(Try<? extends T> other)
```
 - orElse
```
default Try<T> orElse(Supplier<? extends Try<? extends T>> supplier)
```
 - getOrElseGet
```
default T getOrElseGet(Function<? super Throwable,? extends T> other)
```
 - orElseRun
```
default void orElseRun(Consumer<? super Throwable> action)
```
 - getOrElseThrow
```
default <X extends Throwable> T getOrElseThrow(Function<? super Throwable,X> exceptionProvider)
 throws X extends Throwable
```
 Throws:
 
 X extends Throwable
 - peek
```
default Try<T> peek(Consumer<? super T> action)
```
 Applies the action to the value of a Success or does nothing in the case of a Failure.
 
 Specified by:
 
 peek in interface Value<T>
 
 Parameters:
 
 action - A Consumer
 
 Returns:
 
 this Try
 
 Throws:
 
 NullPointerException - if action is null
 - recover
```
default Try<T> recover(Function<? super Throwable,? extends T> f)
```
 Returns this, if this is a Success, otherwise tries to recover the exception of the failure with f, i.e. calling Try.of(() -> f.apply(throwable)).
 
 Parameters:
 
 f - A recovery function taking a Throwable
 
 Returns:
 
 a Try
 
 Throws:
 
 NullPointerException - if f is null
 - recoverWith
```
default Try<T> recoverWith(Function<? super Throwable,? extends Try<? extends T>> f)
```
 Returns this, if this is a Success, otherwise tries to recover the exception of the failure with f, i.e. calling f.apply(cause.getCause()). If an error occurs recovering a Failure, then the new Failure is returned.
 
 Parameters:
 
 f - A recovery function taking a Throwable
 
 Returns:
 
 a Try
 
 Throws:
 
 NullPointerException - if f is null
 - toEither
```
default Either<Throwable,T> toEither()
```
 Converts this Try to an Either.
 
 Returns:
 
 A new Either
 - transform
```
default  U transform(Function<? super Try<T>,? extends U> f)
```
 Transforms this Try.
 
 Type Parameters:
 
 U - Type of transformation result
 
 Parameters:
 
 f - A transformation
 
 Returns:
 
 An instance of type U
 
 Throws:
 
 NullPointerException - if f is null
 - equals
```
boolean equals(Object o)
```
 Description copied from interface: Value
 
 Clarifies that values have a proper equals() method implemented.
 See Object.equals(Object).
 
 Specified by:
 
 equals in interface Value<T>
 
 Overrides:
 
 equals in class Object
 
 Parameters:
 
 o - An object
 
 Returns:
 
 true, if this equals o, false otherwise
 - hashCode
```
int hashCode()
```
 Description copied from interface: Value
 
 Clarifies that values have a proper hashCode() method implemented.
 See Object.hashCode().
 
 Specified by:
 
 hashCode in interface Value<T>
 
 Overrides:
 
 hashCode in class Object
 
 Returns:
 
 The hashcode of this object
 - toString
```
String toString()
```
 Description copied from interface: Value
 
 Clarifies that values have a proper toString() method implemented.
 See Object.toString().
 
 Specified by:
 
 toString in interface Value<T>
 
 Overrides:
 
 toString in class Object
 
 Returns:
 
 A String representation of this object

Interface Try<T>

Nested Class Summary

Method Summary

Methods inherited from interface javaslang.Value

Methods inherited from interface java.lang.Iterable

Method Detail

of

run

sequence

success

failure

narrow

andThen

andThenTry

andThen

andThenTry

failed

filter

filterTry

flatMap

flatMapTry

get

getCause

isEmpty

isFailure

isSingleValued

isSuccess

iterator

map

mapTry

onFailure

onSuccess

orElse

orElse

getOrElseGet

orElseRun

getOrElseThrow

peek

recover

recoverWith

toEither

transform

equals

hashCode

toString