org.apache.brooklyn.util.core.task

Class ValueResolverIterator<T>

java.lang.Object

org.apache.brooklyn.util.core.task.ValueResolverIterator<T>

All Implemented Interfaces:

java.util.Iterator<Maybe<java.lang.Object>>

public class ValueResolverIterator<T>
extends java.lang.Object
implements java.util.Iterator<Maybe<java.lang.Object>>

Resolve one step at a time, returning intermediate results or absent if there's a resolve error. Each step is a single one-level evaluation of the previous value. Use this if you are interested in intermediate suppliers wrapping the end result. Use ValueResolver if you need the deeper-most value.

Constructor Summary

Constructors

Constructor and Description
ValueResolverIterator(ValueResolver<T> resolver)

Method Summary

Modifier and Type	Method and Description
boolean	hasNext() Returns true if the current value is resolvable.
Maybe<T>	last()
Maybe<java.lang.Object>	next() Resolves the value recursively, returning the immediately resolved value.
<S> Maybe<S>	next(java.lang.Class<S> type)
Maybe<java.lang.Object>	nextOrLast(<any> stopCondition)
Maybe<java.lang.Object>	peek()
void	remove()

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Iterator

forEachRemaining

Constructor Detail

ValueResolverIterator

public ValueResolverIterator(ValueResolver<T> resolver)

Method Detail

peek

public Maybe<java.lang.Object> peek()

Returns:

the current element in the iterator. If Maybe.absent() there was a resolve error.

hasNext

public boolean hasNext()

Returns true if the current value is resolvable.

Specified by:

hasNext in interface java.util.Iterator<Maybe<java.lang.Object>>

next

public Maybe<java.lang.Object> next()

Resolves the value recursively, returning the immediately resolved value. If there's a resolve failure a Maybe.absent() is returned containing the failure description as the last element.

Specified by:

next in interface java.util.Iterator<Maybe<java.lang.Object>>

remove

public void remove()

Specified by:

remove in interface java.util.Iterator<Maybe<java.lang.Object>>

nextOrLast

public Maybe<java.lang.Object> nextOrLast(<any> stopCondition)

Returns:

the first resolved value satisfying the stopCondition. If none is found return the last element.

next

public <S> Maybe<S> next(java.lang.Class<S> type)

Returns:

the first resolved value instance of type. If not found returns Maybe.absent() either due to the end reached or a resolve error. To check if there was a resolve error call peek().isAbsent().

last

public Maybe<T> last()

Returns:

the last element of the iterator reached either because resolving no longer possible or there was a resolve error.