Package com.apama.iaf.plugin
Class NormalisedEventIterator
- java.lang.Object
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- com.apama.iaf.plugin.NormalisedEventIterator
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public class NormalisedEventIterator extends java.lang.Object
NormalisedEventIterator implements an iterator interface similar to the C NormalisedEventIterator interface documented in the IAF manual, which can be used for iterating over the fields of a NormalisedEvent. The iterator takes a copy of the contents of the normalised event, so it may be used even after modifications have been made to the associated NormalisedEvent, although its contents will be stale.
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description boolean
back()
back Move the iterator to the previous element of the underlying normalised event instance.java.lang.String
key()
Return the key (name) associated with the current event element pointed to by the iterator.boolean
next()
Move the iterator to the next element of the underlying normalised event instance.boolean
valid()
Check whether the iterator points to a valid element of the normalised event.java.lang.String
value()
Return the value associated with the current event element pointed to by the iterator.
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Method Detail
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valid
public final boolean valid()
Check whether the iterator points to a valid element of the normalised event. Typically used as part of the loop condition when iterating over the contents of an event.- Returns:
true
if the iterator points to a valid element,false
otherwise.
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key
public final java.lang.String key()
Return the key (name) associated with the current event element pointed to by the iterator.- Returns:
- The key/name of the current normalised event element
- Throws:
java.lang.ArrayIndexOutOfBoundsException
- Thrown if valid() isfalse
(due to no values being present, or iteration after the end of the available data.
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value
public final java.lang.String value()
Return the value associated with the current event element pointed to by the iterator. The returned value may be an empty string "", or null to indicate a missing value.- Returns:
- The value of the current normalised event element
- Throws:
java.lang.ArrayIndexOutOfBoundsException
- Thrown if valid() isfalse
(due to no values being present, or iteration after the end of the available data.
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next
public final boolean next()
Move the iterator to the next element of the underlying normalised event instance. The iterator must be in a valid state (such that the valid() function would returntrue
) before this function is called. Note that the order in which elements is returned is not necessarily the same as the order in which they were added. The order may change as elements are added to or removed from the underlying event.- Returns:
true
if the iterator still points to a valid event element after moving forwards,false
otherwise.
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back
public final boolean back()
back Move the iterator to the previous element of the underlying normalised event instance. The iterator must be in a valid state (such that the valid() function would returntrue
) before this function is called. Note that the order in which elements is returned is not necessarily the same as the order in which they were added. The order may change as elements are added to or removed from the underlying event.- Returns:
true
if the iterator still points to a valid event element after moving backwards,false
otherwise.
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