react

Class Try<T>

java.lang.Object

react.Try<T>

Direct Known Subclasses:

Try.Failure, Try.Success

public abstract class Try<T>
extends Object

Represents a computation that either provided a result, or failed with an exception. Monadic methods are provided that allow one to map and compose tries in ways that propagate failure. This class is not itself "reactive", but it facilitates a more straightforward interface and implementation for RFuture and RPromise.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	Try.Failure<T> Represents a failed try.
static class	Try.Success<T> Represents a successful try.

Method Summary

Modifier and Type	Method and Description
static <T> Try<T>	failure(Throwable cause) Creates a failed try.
abstract <R> Try<R>	flatMap(Function<? super T,Try<R>> func) Maps successful tries through func, passes failure through as is.
abstract T	get() Returns the value associated with a successful try, or rethrows the exception if the try failed.
abstract Throwable	getFailure() Returns the cause of failure for a failed try.
boolean	isFailure() Returns try if this is a failed try, false if it is a successful try.
abstract boolean	isSuccess() Returns try if this is a successful try, false if it is a failed try.
static <T,R> Function<Try<T>,Try<R>>	lift(Function<T,R> func) Lifts func, a function on values, to a function on tries.
abstract <R> Try<R>	map(Function<? super T,R> func) Maps successful tries through func, passees failure through as is.
abstract Try<T>	recover(Function<? super Throwable,T> func) Maps failed tries through func, passes success through as is.
static <T> Try<T>	success(T value) Creates a successful try.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

success

public static <T> Try<T> success(T value)

Creates a successful try.

failure

public static <T> Try<T> failure(Throwable cause)

Creates a failed try.

lift

public static <T,R> Function<Try<T>,Try<R>> lift(Function<T,R> func)

Lifts func, a function on values, to a function on tries.

get

public abstract T get()

Returns the value associated with a successful try, or rethrows the exception if the try failed. If the exception is a checked exception, it will be thrown as a the cause of a newly constructed RuntimeException.

getFailure

public abstract Throwable getFailure()

Returns the cause of failure for a failed try. Throws IllegalStateException if called on a successful try.

isSuccess

public abstract boolean isSuccess()

Returns try if this is a successful try, false if it is a failed try.

isFailure

public boolean isFailure()

Returns try if this is a failed try, false if it is a successful try.

map

public abstract <R> Try<R> map(Function<? super T,R> func)

Maps successful tries through func, passees failure through as is.

recover

public abstract Try<T> recover(Function<? super Throwable,T> func)

Maps failed tries through func, passes success through as is. Note: if func throws an exception, you will get back a failure try with the new failure. Ideally one could generalize the type T here but Java doesn't allow type parameters with lower bounds.

flatMap

public abstract <R> Try<R> flatMap(Function<? super T,Try<R>> func)

Maps successful tries through func, passes failure through as is.