com.davisor.data.stream
Class ListIteratorDataStream

java.lang.Object
  com.davisor.data.VoidData
      com.davisor.data.stream.IteratorDataStream
          com.davisor.data.stream.ListIteratorDataStream

All Implemented Interfaces:

Data, DataStream

public class ListIteratorDataStream

extends IteratorDataStream

ListIteratorDataStream represents a data stream that uses a standard Java list iterator to implement stream elements. In particular, the target list may be iterated forward or backward. The elements may or may not be DataValues, and they may or may not be of a mutually equal type. The stream itself has a single type, however.

References to DataValue elements are returned as they are. Elements not of the expected type are converted first to data objects of the proper type, and then the converted objects are returned. The original objects in the source are not changed.

Since:

JDK1.1

See Also:

next(), EnumeratorDataStream, Type

Field Summary

protected boolean

M_reversed

Fields inherited from class com.davisor.data.stream.IteratorDataStream

M_hasNext, M_index, M_iterator, M_metaData, M_nextData

Fields inherited from class com.davisor.data.VoidData

M_type

Fields inherited from interface com.davisor.data.stream.DataStream

INITIAL_INDEX

Constructor Summary

ListIteratorDataStream(java.util.List list, boolean reversed)
Creates a data stream out of a list.

ListIteratorDataStream(java.util.ListIterator iterator, boolean reversed)
Creates a data stream out of an iterator.

ListIteratorDataStream(java.util.ListIterator iterator, Type type, boolean reversed)
Creates a data stream out of an iterator and the given type.

ListIteratorDataStream(java.util.List list, Type type, boolean reversed)
Creates a data stream out of a list and given type.

Method Summary

DataValue

next() Gets the next data value from the stream.

Methods inherited from class com.davisor.data.stream.IteratorDataStream

close, getIndex, hasNext, init, toString

Methods inherited from class com.davisor.data.VoidData

equals, getDataValue, getType, hashCode, setType

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface com.davisor.data.Data

getType

Field Detail

M_reversed

protected boolean M_reversed

Constructor Detail

ListIteratorDataStream

public ListIteratorDataStream(java.util.List list,
                              boolean reversed)
                       throws InvalidDataException

Creates a data stream out of a list. The data stream type is taken from the first element in the list.

Parameters:

list - data list to create a stream from

reversed - controls if stream reads list forwards or backwards

Throws:

InvalidDataException - if the first element is not a DataValue

ListIteratorDataStream

public ListIteratorDataStream(java.util.List list,
                              Type type,
                              boolean reversed)
                       throws InvalidDataException

Creates a data stream out of a list and given type.

Parameters:

list - data collection to create a stream from

type - the type of data in stream

reversed - controls if stream reads list forwards or backwards

Throws:

InvalidDataException - if the first element is not of the given type, and cannot be converted to a data object of that type

ListIteratorDataStream

public ListIteratorDataStream(java.util.ListIterator iterator,
                              boolean reversed)
                       throws InvalidDataException

Creates a data stream out of an iterator. The data stream type is set to AutoType.

Parameters:

iterator - data iterator to create a stream from

reversed - controls if stream reads list forwards or backwards

Throws:

InvalidDataException - if the first element was not a DataValue, and no suitable type could be created for it

ListIteratorDataStream

public ListIteratorDataStream(java.util.ListIterator iterator,
                              Type type,
                              boolean reversed)
                       throws InvalidDataException

Creates a data stream out of an iterator and the given type.

Parameters:

iterator - data iterator to create a stream from

type - the type of data in stream

reversed - controls if stream reads list forwards or backwards

Throws:

InvalidDataException - if the first element is not of the given type, and cannot be converted to a data object of that type

Method Detail

next

public DataValue next()
               throws InvalidDataException

Gets the next data value from the stream.

Specified by:

next in interface DataStream

Overrides:

next in class IteratorDataStream

Throws:

InvalidDataException - if the stream content does not satisfy the stream type.

See Also:

IteratorDataStream.close(), VoidData.getDataValue(java.lang.Object), IteratorDataStream.hasNext(), IteratorDataStream.init(java.util.Iterator)