org.sormula.operation

Class SelectIterator<R>

java.lang.Object

org.sormula.operation.SelectIterator<R>

Type Parameters:

R - class type for row

All Implemented Interfaces:

java.util.Iterator<R>

public class SelectIterator<R>
extends java.lang.Object
implements java.util.Iterator<R>

Iterator for a ScalarSelectOperation. Returned by ScalarSelectOperation.iterator() or may be instantiated and used stand-alone.

Since:

3.0

Author:

Jeff Miller

Constructor Summary

Constructors

Constructor and Description
SelectIterator(ScalarSelectOperation<R> selectOperation) Constructs for a select operation.

Method Summary

Modifier and Type	Method and Description
boolean	hasNext() Tests if there is a row available for next().
R	next() Reads the next row from the select operation or returns the row found in most recent use of hasNext().
void	remove() Throws UnsupportedOperationException.

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Iterator

forEachRemaining

Constructor Detail

SelectIterator

public SelectIterator(ScalarSelectOperation<R> selectOperation)

Constructs for a select operation. All parameters must be set on operation prior to the first use of hasNext(). If ScalarSelectOperation.execute() has not be invoked, then it will be upon first invocation of hasNext().

Parameters:

selectOperation - operation to iterate over

Since:

4.1

Method Detail

hasNext

public boolean hasNext()

Tests if there is a row available for next(). This method will invoke ScalarSelectOperation.readNext() to look ahead to find out if another row is available if it does not already know about next row.

Specified by:

hasNext in interface java.util.Iterator<R>

Returns:

true if at least one more row is available through next(); false if not

next

public R next()

Reads the next row from the select operation or returns the row found in most recent use of hasNext(). This method advances cursor of reads so that repeated invocations will iterate through all rows.

Specified by:

next in interface java.util.Iterator<R>

Returns:

next row or null if no more rows

remove

public void remove()

Throws UnsupportedOperationException.

Specified by:

remove in interface java.util.Iterator<R>