org.apache.commons.collections
public interface MapIterator extends Iterator
Map
.
This iterator is a special version designed for maps. It can be more efficient to use this rather than an entry set iterator where the option is available, and it is certainly more convenient.
A map that provides this interface may not hold the data internally using Map Entry objects, thus this interface can avoid lots of object creation.
In use, this iterator iterates through the keys in the map. After each call
to next()
, the getValue()
method provides direct
access to the value. The value can also be set using setValue()
.
MapIterator it = map.mapIterator(); while (it.hasNext()) { Object key = it.next(); Object value = it.getValue(); it.setValue(newValue); }
Since: Commons Collections 3.0
Version: $Revision: 155406 $ $Date: 2005-02-26 12:55:26 +0000 (Sat, 26 Feb 2005) $
Method Summary | |
---|---|
Object | getKey()
Gets the current key, which is the key returned by the last call
to next() .
|
Object | getValue()
Gets the current value, which is the value associated with the last key
returned by next() .
|
boolean | hasNext()
Checks to see if there are more entries still to be iterated.
|
Object | next()
Gets the next key from the Map .
|
void | remove()
Removes the last returned key from the underlying Map (optional operation).
|
Object | setValue(Object value)
Sets the value associated with the current key (optional operation).
|
next()
.
Returns: the current key
Throws: IllegalStateException if next()
has not yet been called
next()
.
Returns: the current value
Throws: IllegalStateException if next()
has not yet been called
Returns: true
if the iterator has more elements
Map
.
Returns: the next key in the iteration
Throws: java.util.NoSuchElementException if the iteration is finished
Map
(optional operation).
This method can be called once per call to next()
.
Throws: UnsupportedOperationException if remove is not supported by the map IllegalStateException if next()
has not yet been called IllegalStateException if remove()
has already been called
since the last call to next()
Parameters: value the new value
Returns: the previous value
Throws: UnsupportedOperationException if setValue is not supported by the map IllegalStateException if next()
has not yet been called IllegalStateException if remove()
has been called since the
last call to next()