Package aQute.bnd.result

Class Ok<V>

java.lang.Object

aQute.bnd.result.Ok<V>

Type Parameters:

V - The value type

All Implemented Interfaces:

Result<V>

final class Ok<V>
extends java.lang.Object
implements Result<V>

This class represents the Ok side of @{link Result}.

Field Summary

Fields

Modifier and Type	Field	Description
private V	value

Constructor Summary

Constructors

Constructor	Description
Ok(V value)	Constructor.

Method Summary

Modifier and Type	Method	Description
void	accept(ConsumerWithException<? super V> ok, ConsumerWithException<? super java.lang.String> err)	Processes the result.
<U> Result<U>	asError()	If an Err, return this coerced to the desired generic type.
java.util.Optional<java.lang.String>	error()	Returns the error of this instance as an Optional.
<U> Result<U>	flatMap(FunctionWithException<? super V,? extends Result<? extends U>> mapper)	FlatMap the contained value if this is an Ok value.
boolean	isErr()	Returns true if this instance represents an Err value, false otherwise.
boolean	isOk()	Returns true if this instance represents an Ok value, false otherwise.
<U> Result<U>	map(FunctionWithException<? super V,? extends U> mapper)	Map the contained value if this is an Ok value.
Result<V>	mapErr(FunctionWithException<? super java.lang.String,? extends java.lang.CharSequence> mapper)	Map the contained error if this is an Err value.
V	orElse(V orElse)	Returns the contained value if this is an Ok value.
V	orElseGet(SupplierWithException<? extends V> orElseSupplier)	Returns the contained value if this is an Ok value.
<R extends java.lang.Throwable> V	orElseThrow(FunctionWithException<? super java.lang.String,? extends R> throwableSupplier)	Returns the contained value if this is an Ok value.
Result<V>	recover(FunctionWithException<? super java.lang.String,? extends V> recover)	Recover the contained error if this is an Err value.
Result<V>	recoverWith(FunctionWithException<? super java.lang.String,? extends Result<? extends V>> recover)	Recover the contained error if this is an Err value.
java.lang.String	toString()
V	unwrap()	Returns the contained value if this is an Ok value.
V	unwrap(java.lang.CharSequence message)	Express the expectation that this object is an Ok value.
java.util.Optional<V>	value()	Returns the value of this instance as an Optional.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

value

private final V value

Constructor Detail

Ok

Ok(V value)

Constructor.

Parameters:

value - the value

Method Detail

isOk

public boolean isOk()

Returns true if this instance represents an Ok value, false otherwise.

Specified by:

isOk in interface Result<V>

Returns:

true if this instance represents an Ok value, false otherwise.

isErr

public boolean isErr()

Returns true if this instance represents an Err value, false otherwise.

Specified by:

isErr in interface Result<V>

Returns:

true if this instance represents an Err value, false otherwise.

value

public java.util.Optional<V> value()

Returns the value of this instance as an Optional. Returns Optional.empty() if this is an Err instance.

Specified by:

value in interface Result<V>

Returns:

The value of this instance as an Optional. Returns Optional.empty() if this is an Err instance.

error

public java.util.Optional<java.lang.String> error()

Returns the error of this instance as an Optional. Returns Optional.empty() if this is an Ok instance.

Specified by:

error in interface Result<V>

Returns:

The error of this instance as an Optional. Returns Optional.empty() if this is an Ok instance.

unwrap

public V unwrap()

Returns the contained value if this is an Ok value. Otherwise throws a ResultException.

Specified by:

unwrap in interface Result<V>

Returns:

The contained value

unwrap

public V unwrap(java.lang.CharSequence message)
         throws ResultException

Express the expectation that this object is an Ok value. Otherwise throws a ResultException with the specified message.

Specified by:

unwrap in interface Result<V>

Parameters:

message - The message to pass to a potential ResultException. Must not be null.

Throws:

ResultException - If this is an Err instance.

orElse

public V orElse(V orElse)

Returns the contained value if this is an Ok value. Otherwise returns the specified alternate value.

Specified by:

orElse in interface Result<V>

Parameters:

orElse - The value to return if this is an Err instance.

Returns:

The contained value or the alternate value

orElseGet

public V orElseGet(SupplierWithException<? extends V> orElseSupplier)

Returns the contained value if this is an Ok value. Otherwise returns the alternate value supplied by the specified supplier.

Specified by:

orElseGet in interface Result<V>

Parameters:

orElseSupplier - The supplier to supply an alternate value if this is an Err instance. Must not be null.

Returns:

The contained value or the alternate value

orElseThrow

public <R extends java.lang.Throwable> V orElseThrow(FunctionWithException<? super java.lang.String,? extends R> throwableSupplier)
                                              throws R extends java.lang.Throwable

Returns the contained value if this is an Ok value. Otherwise throws the exception supplied by the specified function.

Specified by:

orElseThrow in interface Result<V>

Type Parameters:

R - The exception type.

Parameters:

throwableSupplier - The supplier to supply an exception if this is an Err instance. Must not be null. The supplier must return a non-null result.

Returns:

The contained value.

Throws:

R - The exception returned by the throwableSupplier if this is an Err instance.

R extends java.lang.Throwable

map

public <U> Result<U> map(FunctionWithException<? super V,? extends U> mapper)

Map the contained value if this is an Ok value. Otherwise return this.

Specified by:

map in interface Result<V>

Type Parameters:

U - The new value type.

Parameters:

mapper - The function to map the contained value into a new value. Must not be null.

Returns:

A result containing the mapped value if this is an Ok value. Otherwise this.

mapErr

public Result<V> mapErr(FunctionWithException<? super java.lang.String,? extends java.lang.CharSequence> mapper)

Map the contained error if this is an Err value. Otherwise return this.

Specified by:

mapErr in interface Result<V>

Parameters:

mapper - The function to map the contained error into a new error. Must not be null. The function must return a non-null error.

Returns:

A result containing the mapped error if this is an Err value. Otherwise this.

flatMap

public <U> Result<U> flatMap(FunctionWithException<? super V,? extends Result<? extends U>> mapper)

FlatMap the contained value if this is an Ok value. Otherwise return this.

Specified by:

flatMap in interface Result<V>

Type Parameters:

U - The new value type.

Parameters:

mapper - The function to flatmap the contained value into a new result. Must not be null. The function must return a non-null result.

Returns:

The flatmapped result if this is an Ok value. Otherwise this.

recover

public Result<V> recover(FunctionWithException<? super java.lang.String,? extends V> recover)

Recover the contained error if this is an Err value. Otherwise return this.

To recover with a recovery value of null, the Result.recoverWith(FunctionWithException) method must be used. The specified function for Result.recoverWith(FunctionWithException) can return Result.ok(null) to supply the desired null value.

Specified by:

recover in interface Result<V>

Parameters:

recover - The function to recover the contained error into a new value. Must not be null.

Returns:

A result containing the new non-null value if this is an Err value. Otherwise this if this is an Ok value or the recover function returned null.

recoverWith

public Result<V> recoverWith(FunctionWithException<? super java.lang.String,? extends Result<? extends V>> recover)

Recover the contained error if this is an Err value. Otherwise return this.

Specified by:

recoverWith in interface Result<V>

Parameters:

recover - The function to recover the contained error into a new result. Must not be null. The function must return a non-null value.

Returns:

A result if this is an Err value. Otherwise this.

accept

public void accept(ConsumerWithException<? super V> ok,
                   ConsumerWithException<? super java.lang.String> err)

Processes the result.

Specified by:

accept in interface Result<V>

Parameters:

ok - The consumer called this result is an Ok value. Must not be null.

err - The consumer called when this result is an Err value. Must not be null.

asError

public <U> Result<U> asError()

If an Err, return this coerced to the desired generic type.

Specified by:

asError in interface Result<V>

Type Parameters:

U - The desired generic type of the Err.

Returns:

this

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object