xdev.util.XdevHashtable Maven / Gradle / Ivy
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package xdev.util;
/*-
* #%L
* XDEV Application Framework
* %%
* Copyright (C) 2003 - 2020 XDEV Software
* %%
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation, either version 3 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Lesser Public License for more details.
*
* You should have received a copy of the GNU General Lesser Public
* License along with this program. If not, see
* .
* #L%
*/
import java.util.Enumeration;
import java.util.Hashtable;
import java.util.Map;
import java.util.NoSuchElementException;
import xdev.lang.Copyable;
/**
* The standard {@link Map} in XDEV. Based on {@link Hashtable}.
*
* @see Map
* @see Hashtable
*
* @author XDEV Software
* @param
* type of the key entries.
* @param
*
* @since 2.0
*/
public class XdevHashtable extends Hashtable implements Copyable>
{
/**
* JavaDoc omitted for private field.
*/
private Enumeration cursor = null;
/**
* JavaDoc omitted for private field.
*/
private K currentKey = null;
/**
* Constructs a new, empty {@link XdevHashtable} with a default initial
* capacity (11) and load factor (0.75).
*/
public XdevHashtable()
{
super();
}
/**
* Constructs a new, empty {@link XdevHashtable} with the specified initial
* capacity and default load factor (0.75).
*
* @param initialCapacity
* the initial capacity of the {@link XdevHashtable}.
* @exception IllegalArgumentException
* if the initial capacity is less than zero.
*/
public XdevHashtable(int initialCapacity) throws IllegalArgumentException
{
super(initialCapacity);
}
/**
* Constructs a new {@link XdevHashtable} with the same mappings as the
* given Map. The XdevHashtable is created with an initial capacity
* sufficient to hold the mappings in the given Map and a default load
* factor (0.75).
*
* @param m
* the map whose mappings are to be placed in this map.
* @throws NullPointerException
* if the specified map is null.
*/
public XdevHashtable(Map m) throws NullPointerException
{
super(m);
}
/**
* Constructs a new {@link XdevHashtable} with the given value pairs. The
* given parameters become paired in the order that they are passed to the
* method. The first parameter will be the key, the second parameter will be
* the value for the first pair (and so on)...
*
* @param keysAndValues
* key value pairs in sequence
*
* @throws IllegalArgumentException
* if the parameter count is not even.
*/
public XdevHashtable(Object... keysAndValues) throws IllegalArgumentException
{
super(keysAndValues.length / 2);
if(keysAndValues.length % 2 != 0)
{
throw new IllegalArgumentException("keysAndValues.length % 2 != 0");
}
for(int i = 0; i < keysAndValues.length; i += 2)
{
put((K)keysAndValues[i],(V)keysAndValues[i + 1]);
}
}
/**
* {@inheritDoc}
*/
@Override
public synchronized V put(K key, V value)
{
resetCursor();
return super.put(key,value);
}
/**
* {@inheritDoc}
*/
@Override
public synchronized void putAll(Map t)
{
resetCursor();
super.putAll(t);
}
/**
* {@inheritDoc}
*/
@Override
public synchronized V remove(Object key)
{
resetCursor();
return super.remove(key);
}
/**
* {@inheritDoc}
*/
@Override
public synchronized void clear()
{
resetCursor();
super.clear();
}
/**
* Returns a {@link XdevList} containing all the keys of this
* {@link XdevHashtable}.
*
* @return a {@link XdevList} containing all the keys of this
* {@link XdevHashtable}.
*/
public XdevList getKeys()
{
return new XdevList(keySet());
}
/**
* Returns a {@link XdevList} containing all the values of this
* {@link XdevHashtable}.
*
* @return a {@link XdevList} containing all the values of this
* {@link XdevHashtable}.
*/
public XdevList getValues()
{
return new XdevList(values());
}
/**
* Resets the cursor for this {@link XdevHashtable}.
*/
public void resetCursor()
{
cursor = null;
currentKey = null;
}
/**
* Tests if this {@link XdevHashtable} contains more elements.
*
*
* If this {@link XdevHashtable} contains more elements, the cursor is set
* to next element; otherwise the cursor is reseted via
* {@link #resetCursor()}.
*
* @return true if and only if this {@link XdevHashtable}
* object contains at least one more element to provide;
* false otherwise.
*/
public boolean next()
{
if(cursor == null)
{
cursor = keys();
currentKey = null;
}
boolean next = cursor.hasMoreElements();
if(next)
{
currentKey = cursor.nextElement();
}
else
{
resetCursor();
}
return next;
}
/**
* Returns the key at the current cursor position.
*
* @return the key at the current cursor position.
*
* @see #next()
* @see #resetCursor()
*/
public K getKey()
{
if(cursor == null)
{
throw new NoSuchElementException("Cursor out of Bounds");
}
return currentKey;
}
/**
* Returns the value at the current cursor position.
*
* @return the value at the current cursor position.
*
* @see #next()
* @see #resetCursor()
*/
public V getValue()
{
if(cursor == null)
{
throw new NoSuchElementException("Cursor out of Bounds");
}
return get(currentKey);
}
/**
* {@inheritDoc}
*/
@Override
public String toString()
{
return toString(", ");
}
/**
* Returns a {@link String} representation of all elements of this
* {@link XdevHashtable} separated by the specified separator.
*
* @param separator
* String to separated the list elements.
* @return a {@link String} representation of all elements of this
* {@link XdevHashtable} separated by the specified separator.
*/
public String toString(String separator)
{
StringBuffer sb = new StringBuffer();
Enumeration e = keys();
Object key, val;
int i = 0;
while(e.hasMoreElements())
{
if(i > 0)
{
sb.append(separator);
}
key = e.nextElement();
sb.append(key == this ? "this" : key);
sb.append("=");
val = get(key);
sb.append(val == this ? "this" : String.valueOf(val));
i++;
}
return sb.toString();
}
/**
* Creates a (defensive) copy of this {@link XdevHashtable}.
*
* @return a (defensive) copy of this {@link XdevHashtable}.
*/
public XdevHashtable copy()
{
return new XdevHashtable(this);
}
/**
* {@inheritDoc}
*/
@Override
public synchronized XdevHashtable clone()
{
return copy();
}
}