Package com.saperion.common.lang.iterator

Class Iterators

java.lang.Object

com.saperion.common.lang.iterator.Iterators

public final class Iterators
extends Object

Utility class for iterator treatment.

Author:

agz

Method Summary

Modifier and Type	Method	Description
static <T> T	extractSingleElement(Iterator<? extends T> iteratorInput, Criterion<? super T> criterion)	Returns the one-and-only element of the specified specified input Iterator that satisfies the specified Criterion.
static <T> void	filter(Iterator<T> iteratorInput, Criterion<? super T> criterion, Collection<? super T> colOutput)	Iterates through the element of the specified input Iterator and adds those elements that satisfy the specified Criterion to the specified output Collection.
static <T> ArrayList<T>	newArrayList(Iterator<? extends T> iteratorInput, Criterion<? super T> criterion, int sizeGuess)	Creates a new ArrayList with those elements of the specified input Iterator that satisfy the specified Criterion.
static boolean	startsWith(Iterator<?> iterator1, Iterator<?> iterator2)	Returns whether the first specified Iterator starts with the same elements as the second specified Iterator (by Object.equals(Object)-comparison) and contains at least the same number of elements.

Methods inherited from class java.lang.Object

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

Method Details

filter

public static <T> void filter(Iterator<T> iteratorInput,
 Criterion<? super T> criterion,
 Collection<? super T> colOutput)

Iterates through the element of the specified input Iterator and adds those elements that satisfy the specified Criterion to the specified output Collection.

The specified input Iterator must not be null.

The specified Criterion may be null, in which case all elements of the input Iterator are copied to the output Collection.

The specified output Collection must not be null.

After this call the specified input Iterator will be expired.

Type Parameters:

T - Type of elements of the input Iterator

Parameters:

iteratorInput - input Iterator whose elements are to filter with the specified Criterion and to add to the output Collection

criterion - Criterion to filter the elements of the input Iterator with

colOutput - output Collection to accept the filtered input

newArrayList

public static <T> ArrayList<T> newArrayList(Iterator<? extends T> iteratorInput,
 Criterion<? super T> criterion,
 int sizeGuess)

Creates a new ArrayList with those elements of the specified input Iterator that satisfy the specified Criterion.

The specified input Iterator must not be null.

The specified Criterion may be null, in which case all elements of the input Iterator are copied to the new ArrayList.

After this call the specified input Iterator will be expired.

Type Parameters:

T - Type of the elements of the new ArrayList

Parameters:

iteratorInput - input Iterator whose elements are to filter with the specified Criterion and to add to the new ArrayList

criterion - Criterion to filter the input Iterator with

sizeGuess - size guess of the new list/count of filtered elements

Returns:

new ArrayList with those elements of the specified input Iterator that satisfy the specified Criterion

extractSingleElement

public static <T> T extractSingleElement(Iterator<? extends T> iteratorInput,
 Criterion<? super T> criterion)

Returns the one-and-only element of the specified specified input Iterator that satisfies the specified Criterion.

Returns null if no such element exists.

Throws a runtime exception if more than one element satisfy the specified Criterion.

The specified input Iterator must not be null.

The specified Criterion may be null, in which case the Iterator must not iterate through more than one element.

After this call the specified input Iterator will be expired.

Type Parameters:

T - Type of the element to return

Parameters:

iteratorInput - input Iterator whose elements are to filter with the specified Criterion

criterion - Criterion to filter the input Iterator with

Returns:

the one-and-only element of the specified input Iterator that satisfies the specified Criterion

startsWith

public static boolean startsWith(Iterator<?> iterator1,
 Iterator<?> iterator2)

Returns whether the first specified Iterator starts with the same elements as the second specified Iterator (by Object.equals(Object)-comparison) and contains at least the same number of elements.

If this method returns true, the first Iterator points to the first element that is not contained in the second Iterator and the second Iterator has no more elements to iterate.

If this method returns false, the positions of both Iterators are undefined.

Parameters:

iterator1 - Iterator to test the first objects for

iterator2 - Iterator that contains the sequence of starting objects to test the first Iterator for

Returns:

whether the first specified Iterator starts with the same elements as the second specified Iterator