com.day.util.OrderedStringKeyMap Maven / Gradle / Ivy
/*
* $Id: OrderedStringKeyMap.java 12345 2004-08-22 04:56:09Z fielding $
*
* Copyright 1997-2004 Day Management AG
* Barfuesserplatz 6, 4001 Basel, Switzerland
* All Rights Reserved.
*
* This software is the confidential and proprietary information of
* Day Management AG, ("Confidential Information"). You shall not
* disclose such Confidential Information and shall use it only in
* accordance with the terms of the license agreement you entered into
* with Day.
*/
package com.day.util;
import java.util.*;
/**
* a simple implementation for a map with internal ordering. it actually
* combines a list with a map. but takes only strings as keys.
*
* @version $Revision: 1.22 $, $Date: 2004-08-22 06:56:09 +0200 (Sun, 22 Aug 2004) $
* @author tripod
* @since antbear
* @audience wad
*/
public class OrderedStringKeyMap {
/** the internal list */
private final ArrayList list = new ArrayList();
/** the internal map */
private final HashMap map = new HashMap();
/**
* creates a new OrderedMap
*/
public OrderedStringKeyMap() {
}
/**
* Returns the number of the elelemts in this map
* @return the number of the elelemts in this map
*/
public int size() {
return list.size();
}
/**
* Checks if this map is empty.
*
* @return true if this map is empty;
* false otherwise.
*/
public boolean isEmpty() {
return list.isEmpty();
}
/**
* Checks if this map contains the specified value.
*
* @param o the object the check
*
* @return true if this map contains the value;
* false otherwise.
*/
public boolean contains(Object o) {
return map.containsValue(o);
}
/**
* Checks if this map contains the specified key.
*
* @param key the key to check
*
* @return true if this map contaisn the key;
* false otherwise.
*/
public boolean contains(String key) {
return map.containsKey(key);
}
/**
* Checks if this map contains the specified value.
*
* @param o the object the check
*
* @return true if this map contains the value;
* false otherwise.
*/
public boolean containsValue(Object o) {
return map.containsValue(o);
}
/**
* Checks if this map contains the specified key.
*
* @param key the key to check
*
* @return true if this map contaisn the key;
* false otherwise.
*/
public boolean containsKey(String key) {
return map.containsKey(key);
}
/**
* Returns the value with the given key or null if
* the values is not in this map.
*
* @param key the key of the value
*
* @return the value or null
*/
public Object get(String key) {
return map.get(key);
}
/**
* Returns the element at the specified position in this list.
*
* @param index index of element to return.
* @return the element at the specified position in this list.
* @throws IndexOutOfBoundsException if index is out of range (index
* < 0 || index >= size()).
*/
public Object get(int index) {
return list.get(index);
}
/**
* Returns an iterator over the elements in this list in proper
* sequence.
*
* @return an iterator over the elements in this list in proper sequence.
*/
public Iterator iterator() {
return list.iterator();
}
/**
* Returns an iterator over the elements in this list in proper
* sequence.
*
* @param reverse if set to true, the elemens are iterated in
* reverse order
*
* @return an iterator over the elements in this list in proper sequence.
*/
public Iterator iterator(boolean reverse) {
return reverse ? new ReverseListIterator(list) : list.iterator();
}
/**
* Returns an iterator over all keys in the map in any order.
*
* @return an iterator over all keys in the map in any order.
*/
public Iterator keys() {
return map.keySet().iterator();
}
/**
* Returns an array containing all of the elements in this list
* in the correct order.
*
* @return an array containing all of the elements in this list
* in the correct order.
*/
public Object[] toArray() {
return list.toArray();
}
/**
* Returns an array containing all of the elements in this list in the
* correct order. The runtime type of the returned array is that of the
* specified array. If the list fits in the specified array, it is
* returned therein. Otherwise, a new array is allocated with the runtime
* type of the specified array and the size of this list.
*
* If the list fits in the specified array with room to spare (i.e., the
* array has more elements than the list), the element in the array
* immediately following the end of the collection is set to
* null. This is useful in determining the length of the list
* only if the caller knows that the list does not contain any
* null elements.
*
* @param a the array into which the elements of the list are to
* be stored, if it is big enough; otherwise, a new array of the
* same runtime type is allocated for this purpose.
* @return an array containing the elements of the list.
* @throws ArrayStoreException if the runtime type of a is not a supertype
* of the runtime type of every element in this list.
*/
public Object[] toArray(Object a[]) {
return list.toArray(a);
}
/**
* Removes all of the elements from this key map. The key map will
* be empty after this call returns.
*/
public void clear() {
list.clear();
map.clear();
}
/**
* Puts an element into the map and appends it to the end of the list.
* @param key the key of the element
* @param value the value of the element
*
* @return the old element that was assigned with this key or
* null if there was no such element.
*/
public Object put(String key, Object value) {
Object old=map.put(key, value);
if (old!=null) list.remove(old);
list.add(value);
return old;
}
/**
* Puts an element in this key map and replaces it in the internal list
* if an element with the key already exists, or appends it to the end
* of the list, otherwise.
*
* @param key the key of the element
* @param value the value of the element
*
* @return the old element that was assigned with this key or
* null if there was no such element.
*/
public Object set(String key, Object value) {
Object old=map.put(key, value);
if (old!=null) {
int idx = list.indexOf(old);
list.remove(old);
list.add(idx, value);
} else {
list.add(value);
}
return old;
}
/**
* Searches for the first occurence of the given argument, testing
* for equality using the equals method.
*
* @param value an object.
* @return the index of the first occurrence of the argument in this
* list; returns -1 if the object is not found.
* @see Object#equals(Object)
*/
public int indexOf(Object value) {
return list.indexOf(value);
}
/**
* Inserts the specified element at the specified position in this
* list. Shifts the element currently at that position (if any) and
* any subsequent elements to the right (adds one to their indices).
*
* @param key the key of the element
* @param value element to be inserted.
* @param index index at which the specified element is to be inserted.
*
* @return the old element that was assigned with this key or
* null if there was no such element.
*
* @throws IndexOutOfBoundsException if index is out of range
* (index < 0 || index > size()).
*/
public Object put(String key, Object value, int index) {
Object old = map.remove(key);
if (old!=null) list.remove(old);
list.add(index, value);
map.put(key,value);
return old;
}
/**
* Inserts the specified element above the element specified with
* above.
*
* @param key the key of the element
* @param value element to be inserted.
* @param above the key of the element to insert above
*
* @return the old element that was assigned with this key or
* null if there was no such element.
*/
public Object put(String key, Object value, String above) {
Object old=map.remove(key);
if (old!=null) list.remove(old);
int index=above==null?-1:list.indexOf(map.get(above));
map.put(key, value);
if (index<0) {
list.add(value);
} else {
list.add(index, value);
}
return old;
}
/**
* Removes the mapping for this key from this map if present.
*
* @param key key whose mapping is to be removed from the map.
* @return previous value associated with specified key, or null
* if there was no mapping for key. A null return can
* also indicate that the map previously associated null
* with the specified key.
*/
public Object remove(String key) {
Object old=map.remove(key);
if (old!=null) list.remove(old);
return old;
}
/**
* Removes the element at the specified position in this list.
* Shifts any subsequent elements to the left (subtracts one from their
* indices).
*
* @param index the index of the element to removed.
* @return the element that was removed from the list.
* @throws IndexOutOfBoundsException if index out of range (index
* < 0 || index >= size()).
*/
public Object remove(int index) {
Object old=list.remove(index);
if (old!=null) map.remove(old);
return old;
}
/**
* Returns the last element of this list, or null if this list
* is empty.
*
* @return the last element of this list.
*/
public Object lastElement() {
if (list.isEmpty()) return null;
return list.get(list.size()-1);
}
/**
* Moves the element with the key above the one specified
* with above.
*/
public void move(String key, String above) {
Object elem=map.get(key);
if (elem==null) {
throw new NoSuchElementException(key);
}
if (key.equals(above)) {
return;
}
Object aboveElem;
if (above==null || above.equals("") || (aboveElem=map.get(above))==null) {
list.remove(elem);
list.add(elem);
} else {
list.remove(elem);
list.add(list.indexOf(aboveElem), elem);
}
}
/**
* Returns a collection view of the mappings contained in this map. Each
* element in the returned collection is a Map.Entry. The
* collection is backed by the map, so changes to the map are reflected in
* the collection, and vice-versa. The collection supports element
* removal, which removes the corresponding mapping from the map, via the
* Iterator.remove, Collection.remove,
* removeAll, retainAll, and clear operations.
* It does not support the add or addAll operations.
*
* @return a collection view of the mappings contained in this map.
* @see Map.Entry
*/
public Set entrySet() {
return map.entrySet();
}
/**
* Returns a set view of the keys contained in this map. The set is
* backed by the map, so changes to the map are reflected in the set, and
* vice-versa. The set supports element removal, which removes the
* corresponding mapping from this map, via the Iterator.remove,
* Set.remove, removeAll, retainAll, and
* clear operations. It does not support the add or
* addAll operations.
*
* @return a set view of the keys contained in this map.
*/
public Set keySet() {
return map.keySet();
}
//--------------------------------------------------------------------------
private static final class ReverseListIterator implements Iterator {
/** the list to iterate */
private final List list;
/** the position of the next element to return */
private int pos;
/**
* Constructs a new ReverseListIterator
*
* @param list the list to iterate
*/
public ReverseListIterator(List list) {
this.list = list;
pos = list.size()-1;
}
/**
* @see Iterator#hasNext()
*/
public boolean hasNext() {
return pos>=0;
}
/**
* @see Iterator#next()
*/
public Object next() throws NoSuchElementException {
if (pos<0) {
throw new NoSuchElementException();
}
return list.get(pos--);
}
/**
* @see Iterator#remove()
*/
public void remove() {
throw new UnsupportedOperationException();
}
}
}