org.wildfly.discovery.ArrayIterator Maven / Gradle / Ivy
Go to download
This artifact provides a single jar that contains all classes required to use remote EJB and JMS, including
all dependencies. It is intended for use by those not using maven, maven users should just import the EJB and
JMS BOM's instead (shaded JAR's cause lots of problems with maven, as it is very easy to inadvertently end up
with different versions on classes on the class path).
/*
* JBoss, Home of Professional Open Source.
* Copyright 2016 Red Hat, Inc., and individual contributors
* as indicated by the @author tags.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.wildfly.discovery;
import java.util.ListIterator;
import java.util.NoSuchElementException;
import org.wildfly.common.Assert;
/**
* A read-only iterator over an array.
*
* @author David M. Lloyd
*/
final class ArrayIterator implements ListIterator {
private final E[] elements;
private final boolean descending;
private int idx;
/**
* Construct a new instance.
*
* @param elements the elements to iterate over
*/
public ArrayIterator(final E[] elements) {
this(elements, false);
}
/**
* Construct a new instance.
*
* @param elements the elements to iterate over
* @param descending {@code true} to iterate in descending order, {@code false} otherwise
*/
public ArrayIterator(final E[] elements, final boolean descending) {
this(elements, descending, descending ? elements.length : 0);
}
/**
* Construct a new instance.
*
* @param elements the elements to iterate over
* @param startIdx the starting index (must be within the bounds of {@code elements})
*/
public ArrayIterator(final E[] elements, final int startIdx) {
this(elements, false, startIdx);
}
/**
* Construct a new instance.
*
* @param elements the elements to iterate over
* @param descending {@code true} to iterate in descending order, {@code false} otherwise
* @param startIdx the starting index (must be within the bounds of {@code elements})
*/
public ArrayIterator(final E[] elements, final boolean descending, final int startIdx) {
Assert.checkNotNullParam("elements", elements);
Assert.checkMinimumParameter("startIdx", 0, startIdx);
Assert.checkMaximumParameter("startIdx", elements.length, startIdx);
this.elements = elements;
this.descending = descending;
this.idx = startIdx;
}
// ListIterator methods
/**
* Determine if there are more elements to iterate over in the reverse direction of this iterator.
*
* @return {@code true} if there are more elements, {@code false} otherwise
*/
public boolean hasPrevious() {
return descending ? idx < elements.length : idx > 0;
}
/**
* Determine if there are more elements to iterate over in the direction of this iterator.
*
* @return {@code true} if there are more elements, {@code false} otherwise
*/
public boolean hasNext() {
return descending ? idx > 0 : idx < elements.length;
}
/**
* Get the next element in the reverse direction of this iterator.
*
* @return the next element
*/
public E previous() {
if (! hasPrevious()) throw new NoSuchElementException();
return elements[descending ? idx ++ : -- idx];
}
/**
* Get the next element in the direction of this iterator.
*
* @return the next element
*/
public E next() {
if (! hasNext()) throw new NoSuchElementException();
return elements[descending ? -- idx : idx ++];
}
/**
* Get the next index in the direction of this iterator.
*
* @return the next index
*/
public int nextIndex() {
return descending ? idx - 1 : idx;
}
/**
* Get the next index in the reverse direction of this iterator.
*
* @return the next index
*/
public int previousIndex() {
return descending ? idx : idx - 1;
}
// Unsupported stuff
/**
* Unsupported.
*/
public void remove() {
throw Assert.unsupported();
}
/**
* Unsupported.
*
* @param e ignored
*/
public void set(final E e) {
throw Assert.unsupported();
}
/**
* Unsupported.
*
* @param e ignored
*/
public void add(final E e) {
throw Assert.unsupported();
}
}