Package org.apache.velocity.tools.generic

Class LoopTool.ManagedIterator

  • All Implemented Interfaces:
    Iterator
    Enclosing class:
    LoopTool
    public static class LoopTool.ManagedIterator
extends Object
implements Iterator
    Iterator implementation that wraps a standard Iterator and allows it to be prematurely stopped, skipped ahead, and associated with a name for advanced nested loop control. This also allows a arbitrary LoopTool.ActionConditions to be added in order to have it automatically skip over or stop before certain elements in the iterator.

    • Method Detail

      • getName

        public String getName()
        Returns the name of this instance.

      • isFirst

        public boolean isFirst()
        Returns true if either 0 or 1 elements have been returned by next().

      • isLast

        public boolean isLast()
        Returns true if the last element returned by next() is the last element available in the iterator being managed which satisfies any/all LoopTool.ActionConditions set for this instance. Otherwise, returns false.

      • getFirst

        public boolean getFirst()
        Returns the result of isFirst(). Exists to allow $loop.this.first syntax.

      • getLast

        public boolean getLast()
        Returns the result of isLast(). Exists to allow $loop.this.last syntax.

      • hasNext

        public boolean hasNext()
        Returns true if there are more elements in the iterator being managed by this instance which satisfy all the LoopTool.ActionConditions set for this instance. Returns false if there are no more valid elements available.
        Specified by:
        hasNext in interface Iterator

      • getHasNext

        public boolean getHasNext()
        Returns the result of hasNext(). Exists to allow $loop.this.hasNext syntax.

      • isSyncedWith

        public boolean isSyncedWith​(String name)
        Returns true if this ManagedIterator has a sync'ed iterator with the specified name.

      • get

        public Object get​(String name)
        Returns the parallel value from the specified sync'ed iterator. If no sync'ed iterator exists with that name or that iterator is finished, this will return null.

      • getCount

        public int getCount()
        Returns the number of elements returned by next() so far.

      • getIndex

        public int getIndex()
        Returns the 0-based index of the current item.

      • remove

        public void remove()
        This operation is unsupported.
        Specified by:
        remove in interface Iterator

      • stop

        public void stop()
        Stops this iterator from doing any further iteration.

      • sync

        public LoopTool.ManagedIterator sync​(Object iterable)

        Adds another iterator to be kept in sync with the one being managed by this instance. The values of the parallel iterator can be retrieved from the LoopTool under the name s"synced" (e.g. $loop.synced or $loop.get('synced')) and are automatically updated for each iteration by this instance.

        NOTE: if you are sync'ing multiple iterators with the same managed iterator, you must use sync(Object,String) or else your the later iterators will simply replace the earlier ones under the default 'synced' key.

        Returns:
        This same LoopTool.ManagedIterator instance
        See Also:
        LoopTool.SyncedIterator, get(String)

      • sync

        public LoopTool.ManagedIterator sync​(Object iterable,
                                     String name)
        Adds another iterator to be kept in sync with the one being managed by this instance. The values of the parallel iterator can be retrieved from the LoopTool under the name specified here (e.g. $loop.name or $loop.get('name')) and are automatically updated for each iteration by this instance.
        Returns:
        This same LoopTool.ManagedIterator instance
        See Also:
        LoopTool.SyncedIterator, get(String)