pu.pi.collect

Class Iterators

java.lang.Object

pu.pi.collect.Iterators

public final class Iterators
extends java.lang.Object

Author: xiaoxing Date: 29/09/13

Method Summary

Modifier and Type	Method and Description
static <T> java.util.Iterator<java.util.List<T>>	partition(java.util.Iterator<T> iterator, int size) Divides an iterator into unmodifiable sublists of the given size (the final list may be smaller).
static <T> java.util.Iterator<java.util.List<T>>	partition(java.util.List<T> list, int size) Partition List,better performance with RandomAccess type.

Methods inherited from class java.lang.Object

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

Method Detail

partition

public static <T> java.util.Iterator<java.util.List<T>> partition(java.util.Iterator<T> iterator,
                                                                  int size)

Divides an iterator into unmodifiable sublists of the given size (the final list may be smaller). For example, partitioning an iterator containing [a, b, c, d, e] with a partition size of 3 yields [[a, b, c], [d, e]] -- an outer iterator containing two inner lists of three and two elements, all in the original order.

The returned lists implement RandomAccess.

Parameters:

iterator - the iterator to return a partitioned view of

size - the desired size of each partition (the last may be smaller)

Returns:

an iterator of immutable lists containing the elements of iterator divided into partitions

Throws:

java.lang.IllegalArgumentException - if size is nonpositive

partition

public static <T> java.util.Iterator<java.util.List<T>> partition(java.util.List<T> list,
                                                                  int size)

Partition List,better performance with RandomAccess type. next method is atomic.

Type Parameters:

T - Element type.

Parameters:

list - Data.

size - Chunk size.

Returns:

Partitioned chunks.