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'databene commons' is an open source Java library by Volker Bergmann.
It provides extensions to the Java core library by utility classes, abstract concepts
and concrete implementations.
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/*
* Copyright (C) 2004-2015 Volker Bergmann ([email protected]).
* All rights reserved.
*
* 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.databene.commons.collection;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;
import java.util.ListIterator;
/**
* Combines several {@link List} components to be treated as a single list which contains all component lists' elements.
* Created: 22.08.2012 17:53:31
* @param the type of the collection's elements
* @since 0.5.18
* @author Volker Bergmann
*/
public class CompositeList implements List, Serializable {
private static final long serialVersionUID = -6652107866866558487L;
List> components;
@SuppressWarnings("unchecked")
public CompositeList(List... components) {
this.components = new ArrayList>();
for (List component : components) {
if (component == null)
throw new IllegalArgumentException("Component is null");
this.components.add((List) component);
}
}
@Override
public boolean add(E element) {
return getOrCreateLastComponent().add(element);
}
@Override
public void add(int index, E element) {
for (List component : components) {
if (index < component.size()) {
component.add(index, element);
return;
}
index -= component.size();
}
if (index == 0) {
getOrCreateLastComponent().add(element);
return;
}
throw new IndexOutOfBoundsException("Index " + index + " does not exist (I have " + size() + " elements)");
}
@Override
public boolean addAll(Collection elements) {
return getOrCreateLastComponent().addAll(elements);
}
@Override
public boolean addAll(int index, Collection elements) {
for (List component : components) {
if (index < component.size()) {
return component.addAll(index, elements);
}
index -= component.size();
}
if (index == 0)
return getOrCreateLastComponent().addAll(elements);
throw new IndexOutOfBoundsException("Index " + index + " does not exist (I have " + size() + " elements)");
}
@Override
public void clear() {
this.components.clear();
}
@Override
public boolean contains(Object element) {
for (List component : components)
if (component.contains(element))
return true;
return false;
}
@Override
public boolean containsAll(Collection elements) {
for (Object element : elements)
if (!contains(element))
return false;
return true;
}
@Override
public E get(int index) {
for (List component : components) {
if (index < component.size())
return component.get(index);
index -= component.size();
}
throw new IndexOutOfBoundsException("Index " + index + " does not exist (I have " + size() + " elements)");
}
@Override
public E set(int index, E element) {
for (List component : components) {
if (index < component.size())
return component.set(index, element);
index -= component.size();
}
throw new IndexOutOfBoundsException("Index " + index + " does not exist (I have " + size() + " elements)");
}
@Override
public int indexOf(Object element) {
int offset = 0;
for (List component : components) {
int index = component.indexOf(element);
if (index >= 0)
return offset + index;
offset += component.size();
}
return -1;
}
@Override
public boolean isEmpty() {
for (List component : components)
if (!component.isEmpty())
return false;
return true;
}
@Override
public Iterator iterator() {
return new SubIterator();
}
@Override
public int lastIndexOf(Object element) {
for (int i = components.size() - 1; i >= 0; i--) {
List component = components.get(i);
int index = component.lastIndexOf(element);
if (index >= 0) {
int offset = 0;
for (int j = 0; j < i; j++)
offset += components.get(j).size();
return offset + index;
}
}
return -1;
}
@Override
public ListIterator listIterator() {
return new SubIterator();
}
@Override
public ListIterator listIterator(int index) {
return new SubIterator(index);
}
@Override
public boolean remove(Object element) {
for (List component : components)
if (component.remove(element))
return true;
return false;
}
@Override
public E remove(int index) {
for (List component : components) {
if (index < component.size())
return component.remove(index);
index -= component.size();
}
throw new IndexOutOfBoundsException("Tried to remove index " + index + " from a list with " + size() + " elements");
}
@Override
public boolean removeAll(Collection elements) {
boolean result = false;
for (List component : components)
if (component.removeAll(elements))
result = true;
return result;
}
@Override
public boolean retainAll(Collection elements) {
boolean result = false;
for (List component : components)
if (component.retainAll(elements))
result = true;
return result;
}
@Override
public int size() {
int result = 0;
for (List component : components)
result += component.size();
return result;
}
@Override
public List subList(int fromIndex, int toIndex) {
List list = new ArrayList(toIndex - fromIndex + 1);
for (int i = fromIndex; i < toIndex; i++)
list.add(get(i));
return list;
}
@Override
public Object[] toArray() {
return toArray(new Object[size()]);
}
@SuppressWarnings("unchecked")
@Override
public T[] toArray(T[] array) {
int offset = 0;
for (List component : components) {
for (int i = 0; i < components.size(); i++)
array[offset + i] = (T) component.get(i);
offset += component.size();
}
return array;
}
// private helpers -------------------------------------------------------------------------------------------------
private List getOrCreateLastComponent() {
if (components.size() == 0)
this.components.add(new ArrayList());
return components.get(components.size() - 1);
}
// java.lang.Object overrides --------------------------------------------------------------------------------------
@Override
public String toString() {
return components.toString();
}
public class SubIterator implements ListIterator {
private int superIndex;
private int subIndex;
private int totalIndex;
public SubIterator() {
this(0);
}
public SubIterator(int offset) {
this.superIndex = 0;
this.subIndex = 0;
this.totalIndex = 0;
for (int i = 0; i < offset; i++)
next();
}
@Override
public boolean hasNext() {
return (totalIndex < size());
}
@Override
public E next() {
List currentComponent = components.get(superIndex);
while (subIndex >= currentComponent.size() && superIndex < components.size() - 1) {
++superIndex;
currentComponent = components.get(superIndex);
subIndex = 0;
}
totalIndex++;
return currentComponent.get(subIndex++);
}
@Override
public int nextIndex() {
return totalIndex;
}
@Override
public boolean hasPrevious() {
return (subIndex > 0 || superIndex > 0);
}
@Override
public E previous() {
List currentComponent = components.get(superIndex);
while (subIndex <= 0 && superIndex > 0) {
--superIndex;
currentComponent = components.get(superIndex);
subIndex = currentComponent.size();
}
totalIndex--;
return currentComponent.get(--subIndex);
}
@Override
public int previousIndex() {
return totalIndex - 1;
}
@Override
public void remove() {
throw new UnsupportedOperationException("Not supported");
}
@Override
public void add(E newValue) {
throw new UnsupportedOperationException("Not supported");
}
@Override
public void set(E newValue) {
throw new UnsupportedOperationException("Not supported");
}
}
}