com.aol.cyclops.trycatch

Interface Try<T,X extends java.lang.Throwable>

Type Parameters:

T - Return type (success)

X - Base Error type

All Superinterfaces:

com.aol.cyclops.objects.Decomposable, java.lang.Iterable<T>, com.aol.cyclops.matcher.recursive.Matchable, java.util.function.Supplier<T>, com.aol.cyclops.sequence.streamable.ToStream<T>, com.aol.cyclops.value.ValueObject

All Known Implementing Classes:

Failure, Success

public interface Try<T,X extends java.lang.Throwable>
extends java.util.function.Supplier<T>, com.aol.cyclops.value.ValueObject, com.aol.cyclops.sequence.streamable.ToStream<T>

Light weight Try Monad Fail fast behaviour with more explicit declararions required compared to with scala.util.Try and javaslang.monad.Try. This is probably closer to how most Java devs currently handle exceptions. Goals / features Support for init block / try block / finally block Try with resources Try with multiple resources Does not automatically catch exceptions in combinators Can target specific exception types Exception types to be caught can be specified in xxxWithCatch methods Handle exceptions conciously, not coding bugs Fluent step builders Fail fast

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static interface	Try.AndFinally<T,V,X extends java.lang.Throwable>
static interface	Try.CheckedConsumer<T,X extends java.lang.Throwable>
static interface	Try.CheckedFunction<T,R,X extends java.lang.Throwable>
static interface	Try.CheckedRunnable<X extends java.lang.Throwable>
static interface	Try.CheckedSupplier<T,X extends java.lang.Throwable>
static interface	Try.Init<X extends java.lang.Throwable>
static class	Try.MyFinallyBlock<T,V,X extends java.lang.Throwable>
static class	Try.MyInit<X extends java.lang.Throwable>
static class	Try.MyTryCatch<V,X extends java.lang.Throwable>
static interface	Try.TryCatch<V,X extends java.lang.Throwable>

Method Summary

Modifier and Type	Method and Description
com.aol.cyclops.monad.AnyM<T>	anyM()
com.aol.cyclops.monad.AnyM<X>	anyMFailure()
com.aol.cyclops.monad.AnyM<T>	anyMSuccess()
static <X extends java.lang.Throwable> Try.Init<X>	catchExceptions(java.lang.Class<? extends X>... classes) Fluent step builder for Try / Catch / Finally and Try with resources equivalents.
java.util.Optional<T>	filter(java.util.function.Predicate<T> p)
<R> Try<R,X>	flatMap(java.util.function.Function<T,Try<R,X>> fn)
Try<T,X>	flatten() Flatten a nested Try Structure
void	foreach(java.util.function.Consumer<T> consumer)
void	foreachFailed(java.util.function.Consumer<X> consumer)
T	get()
boolean	isFailure()
boolean	isSuccess()
<R> Try<R,X>	map(java.util.function.Function<T,R> fn)
static <T,X extends java.lang.Throwable> Try<T,X>	of(T value, java.lang.Class<? extends java.lang.Throwable>... classes) Return a Try that will catch specified exceptions when map / flatMap called For use with liftM / liftM2 and For Comprehensions (when Try is at the top level)
Try<T,X>	onFail(java.lang.Class<? extends X> t, java.util.function.Consumer<X> consumer)
Try<T,X>	onFail(java.util.function.Consumer<X> consumer)
T	orElse(T value)
T	orElseGet(java.util.function.Supplier<T> value)
default Try<T,X>	peek(java.util.function.Consumer<T> consumer)
default Try<T,X>	peekFailed(java.util.function.Consumer<X> consumer)
Success<T,X>	recover(java.util.function.Function<X,T> fn)
Try<T,X>	recoverFor(java.lang.Class<? extends X> t, java.util.function.Function<X,T> fn) Recover if exception is of specified type
Success<T,X>	recoverWith(java.util.function.Function<X,Success<T,X>> fn) flatMap recovery
Try<T,X>	recoverWithFor(java.lang.Class<? extends X> t, java.util.function.Function<X,Success<T,X>> fn) FlatMap recovery function if exception is of specified type
static <X extends java.lang.Throwable> Try<java.lang.Void,X>	runWithCatch(Try.CheckedRunnable cf, java.lang.Class<? extends X>... classes) Try to execute supplied Runnable and will Catch specified Excpetions or java.lang.Exception if none specified.
java.util.stream.Stream<T>	stream()
void	throwException() Throw exception if Failure, do nothing if success
java.util.Optional<X>	toFailedOptional()
java.util.stream.Stream<X>	toFailedStream()
java.util.Optional<T>	toOptional()
static <T,X extends java.lang.Throwable> Try<T,X>	withCatch(Try.CheckedSupplier<T,X> cf, java.lang.Class<? extends X>... classes) Try to execute supplied Supplier and will Catch specified Excpetions or java.lang.Exception if none specified.

Methods inherited from interface com.aol.cyclops.matcher.recursive.Matchable

getMatchable, listOfValues, matches, matches, matches, matches, matches, mayMatch, mayMatch, mayMatch, mayMatch, mayMatch, of, ofDecomposable, ofStream

Methods inherited from interface com.aol.cyclops.objects.Decomposable

unapply, unwrap

Methods inherited from interface com.aol.cyclops.sequence.streamable.ToStream

getStreamable, isEmpty, iterator, reveresedSequenceM, reveresedStream, sequenceM

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Method Detail

anyM

com.aol.cyclops.monad.AnyM<T> anyM()

Returns:

This monad, wrapped as AnyM of Success

anyMFailure

com.aol.cyclops.monad.AnyM<X> anyMFailure()

Returns:

This monad, wrapped as AnyM of Failure

anyMSuccess

com.aol.cyclops.monad.AnyM<T> anyMSuccess()

Returns:

This monad, wrapped as AnyM of Success

get

T get()

Specified by:

get in interface java.util.function.Supplier<T>

Returns:

Successful value or will throw Throwable (X) if Failire

throwException

void throwException()

Throw exception if Failure, do nothing if success

orElse

T orElse(T value)

Parameters:

value - Return value supplied if Failure, otherwise return Success value

Returns:

Success value or supplied value

orElseGet

T orElseGet(java.util.function.Supplier<T> value)

Parameters:

value - from supplied Supplier if Failure otherwise return Success value

Returns:

Success value

map

<R> Try<R,X> map(java.util.function.Function<T,R> fn)

Parameters:

fn - Map success value from T to R. Do nothing if Failure (return this)

Returns:

New Try with mapped value (Success) or this (Failure)

flatMap

<R> Try<R,X> flatMap(java.util.function.Function<T,Try<R,X>> fn)

Parameters:

fn - FlatMap success value or Do nothing if Failure (return this)

Returns:

Try returned from FlatMap fn

filter

java.util.Optional<T> filter(java.util.function.Predicate<T> p)

Parameters:

p - Convert a Success to a Failure (with a null value for Exception) if predicate does not hold. Do nothing to a Failure

Returns:

this if Success and Predicate holds, or if Failure. New Failure if Success and Predicate fails

onFail

Try<T,X> onFail(java.util.function.Consumer<X> consumer)

Parameters:

consumer - Accept Exception if present (Failure)

Returns:

this

onFail

Try<T,X> onFail(java.lang.Class<? extends X> t,
                java.util.function.Consumer<X> consumer)

Parameters:

t - Class type of match Exception against

consumer - Accept Exception if present (Failure) and if class types match

Returns:

this

recover

Success<T,X> recover(java.util.function.Function<X,T> fn)

Parameters:

fn - Recovery function - map from a failure to a Success.

Returns:

new Success

recoverWith

Success<T,X> recoverWith(java.util.function.Function<X,Success<T,X>> fn)

flatMap recovery

Parameters:

fn - Recovery FlatMap function. Map from a failure to a Success

Returns:

Success from recovery function

recoverFor

Try<T,X> recoverFor(java.lang.Class<? extends X> t,
                    java.util.function.Function<X,T> fn)

Recover if exception is of specified type

Parameters:

t - Type of exception to match against

fn - Recovery function

Returns:

New Success if failure and types match / otherwise this

recoverWithFor

Try<T,X> recoverWithFor(java.lang.Class<? extends X> t,
                        java.util.function.Function<X,Success<T,X>> fn)

FlatMap recovery function if exception is of specified type

Parameters:

t - Type of exception to match against

fn - Recovery FlatMap function. Map from a failure to a Success

Returns:

Success from recovery function or this and types match or if already Success

flatten

Try<T,X> flatten()

Flatten a nested Try Structure

Returns:

Lowest nested Try

toOptional

java.util.Optional<T> toOptional()

Returns:

Optional present if Success, Optional empty if failure

stream

java.util.stream.Stream<T> stream()

Specified by:

stream in interface com.aol.cyclops.sequence.streamable.ToStream<T>

Returns:

Stream with value if Sucess, Empty Stream if failure

toFailedOptional

java.util.Optional<X> toFailedOptional()

Returns:

Optional present if Failure (with Exception), Optional empty if Success

toFailedStream

java.util.stream.Stream<X> toFailedStream()

Returns:

Stream with error if Failure, Empty Stream if success

isSuccess

boolean isSuccess()

Returns:

true if Success / false if Failure

isFailure

boolean isFailure()

Returns:

True if Failure / false if Success

foreach

void foreach(java.util.function.Consumer<T> consumer)

Parameters:

consumer - Accept value if Success / not called on Failure

foreachFailed

void foreachFailed(java.util.function.Consumer<X> consumer)

Parameters:

consumer - Accept value if Failure / not called on Failure

peek

default Try<T,X> peek(java.util.function.Consumer<T> consumer)

Parameters:

consumer - Accept value if Success

Returns:

this

peekFailed

default Try<T,X> peekFailed(java.util.function.Consumer<X> consumer)

Parameters:

consumer - Accept Exception if Failure

Returns:

this

of

@SafeVarargs
static <T,X extends java.lang.Throwable> Try<T,X> of(T value,
                                                                  java.lang.Class<? extends java.lang.Throwable>... classes)

Return a Try that will catch specified exceptions when map / flatMap called For use with liftM / liftM2 and For Comprehensions (when Try is at the top level)

Parameters:

value - Initial value

classes - Exceptions to catch during map / flatMap

Returns:

Try instance

withCatch

@SafeVarargs
static <T,X extends java.lang.Throwable> Try<T,X> withCatch(Try.CheckedSupplier<T,X> cf,
                                                                         java.lang.Class<? extends X>... classes)

Try to execute supplied Supplier and will Catch specified Excpetions or java.lang.Exception if none specified.

Parameters:

cf - CheckedSupplier to attempt to execute

classes - Exception types to catch (or java.lang.Exception if none specified)

Returns:

New Try

runWithCatch

@SafeVarargs
static <X extends java.lang.Throwable> Try<java.lang.Void,X> runWithCatch(Try.CheckedRunnable cf,
                                                                                       java.lang.Class<? extends X>... classes)

Try to execute supplied Runnable and will Catch specified Excpetions or java.lang.Exception if none specified.

Parameters:

cf - CheckedRunnable to attempt to execute

classes - Exception types to catch (or java.lang.Exception if none specified)

Returns:

New Try

catchExceptions

@SafeVarargs
static <X extends java.lang.Throwable> Try.Init<X> catchExceptions(java.lang.Class<? extends X>... classes)

Fluent step builder for Try / Catch / Finally and Try with resources equivalents. Start with Exception types to catch.

Parameters:

classes - Exception types to catch

Returns:

Next step in the fluent Step Builder