Java tutorial
/* =========================================================== * JFreeChart : a free chart library for the Java(tm) platform * =========================================================== * * (C) Copyright 2000-2013, by Object Refinery Limited and Contributors. * * Project Info: http://www.jfree.org/jfreechart/index.html * * This library 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 2.1 of the License, or * (at your option) any later version. * * This library 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 Lesser General Public * License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, * USA. * * [Oracle and Java are registered trademarks of Oracle and/or its affiliates. * Other names may be trademarks of their respective owners.] * * ----------------------- * DefaultKeyedValues.java * ----------------------- * (C) Copyright 2002-2013, by Object Refinery Limited. * * Original Author: David Gilbert (for Object Refinery Limited); * Contributor(s): Thomas Morgner; * * Changes: * -------- * 31-Oct-2002 : Version 1 (DG); * 11-Feb-2003 : Fixed bug in getValue(key) method for unrecognised key (DG); * 05-Mar-2003 : Added methods to sort stored data 'by key' or 'by value' (DG); * 13-Mar-2003 : Implemented Serializable (DG); * 08-Apr-2003 : Modified removeValue(Comparable) method to fix bug 717049 (DG); * 18-Aug-2003 : Implemented Cloneable (DG); * 27-Aug-2003 : Moved SortOrder from org.jfree.data --> org.jfree.util (DG); * 09-Feb-2004 : Modified getIndex() method - see bug report 893256 (DG); * 15-Sep-2004 : Updated clone() method and added PublicCloneable * interface (DG); * 25-Nov-2004 : Small update to the clone() implementation (DG); * 24-Feb-2005 : Added methods addValue(Comparable, double) and * setValue(Comparable, double) for convenience (DG); * ------------- JFREECHART 1.0.x --------------------------------------------- * 31-Jul-2006 : Added a clear() method (DG); * 01-Aug-2006 : Added argument check to getIndex() method (DG); * 30-Apr-2007 : Added insertValue() methods (DG); * 31-Oct-2007 : Performance improvements by using separate lists for keys and * values (TM); * 21-Nov-2007 : Fixed bug in removeValue() method from previous patch (DG); * 03-Jul-2013 : Use ParamChecks (DG); * */ package org.jfree.data; import java.io.Serializable; import java.util.ArrayList; import java.util.Arrays; import java.util.Comparator; import java.util.HashMap; import java.util.List; import org.jfree.chart.util.ParamChecks; import org.jfree.util.PublicCloneable; import org.jfree.util.SortOrder; /** * An ordered list of (key, value) items. This class provides a default * implementation of the {@link KeyedValues} interface. */ public class DefaultKeyedValues implements KeyedValues, Cloneable, PublicCloneable, Serializable { /** For serialization. */ private static final long serialVersionUID = 8468154364608194797L; /** Storage for the keys. */ private ArrayList keys; /** Storage for the values. */ private ArrayList values; /** * Contains (key, Integer) mappings, where the Integer is the index for * the key in the list. */ private HashMap indexMap; /** * Creates a new collection (initially empty). */ public DefaultKeyedValues() { this.keys = new ArrayList(); this.values = new ArrayList(); this.indexMap = new HashMap(); } /** * Returns the number of items (values) in the collection. * * @return The item count. */ @Override public int getItemCount() { return this.indexMap.size(); } /** * Returns a value. * * @param item the item of interest (zero-based index). * * @return The value (possibly <code>null</code>). * * @throws IndexOutOfBoundsException if <code>item</code> is out of bounds. */ @Override public Number getValue(int item) { return (Number) this.values.get(item); } /** * Returns a key. * * @param index the item index (zero-based). * * @return The row key. * * @throws IndexOutOfBoundsException if <code>item</code> is out of bounds. */ @Override public Comparable getKey(int index) { return (Comparable) this.keys.get(index); } /** * Returns the index for a given key. * * @param key the key (<code>null</code> not permitted). * * @return The index, or <code>-1</code> if the key is not recognised. * * @throws IllegalArgumentException if <code>key</code> is * <code>null</code>. */ @Override public int getIndex(Comparable key) { ParamChecks.nullNotPermitted(key, "key"); final Integer i = (Integer) this.indexMap.get(key); if (i == null) { return -1; // key not found } return i.intValue(); } /** * Returns the keys for the values in the collection. * * @return The keys (never <code>null</code>). */ @Override public List getKeys() { return (List) this.keys.clone(); } /** * Returns the value for a given key. * * @param key the key (<code>null</code> not permitted). * * @return The value (possibly <code>null</code>). * * @throws UnknownKeyException if the key is not recognised. * * @see #getValue(int) */ @Override public Number getValue(Comparable key) { int index = getIndex(key); if (index < 0) { throw new UnknownKeyException("Key not found: " + key); } return getValue(index); } /** * Updates an existing value, or adds a new value to the collection. * * @param key the key (<code>null</code> not permitted). * @param value the value. * * @see #addValue(Comparable, Number) */ public void addValue(Comparable key, double value) { addValue(key, new Double(value)); } /** * Adds a new value to the collection, or updates an existing value. * This method passes control directly to the * {@link #setValue(Comparable, Number)} method. * * @param key the key (<code>null</code> not permitted). * @param value the value (<code>null</code> permitted). */ public void addValue(Comparable key, Number value) { setValue(key, value); } /** * Updates an existing value, or adds a new value to the collection. * * @param key the key (<code>null</code> not permitted). * @param value the value. */ public void setValue(Comparable key, double value) { setValue(key, new Double(value)); } /** * Updates an existing value, or adds a new value to the collection. * * @param key the key (<code>null</code> not permitted). * @param value the value (<code>null</code> permitted). */ public void setValue(Comparable key, Number value) { ParamChecks.nullNotPermitted(key, "key"); int keyIndex = getIndex(key); if (keyIndex >= 0) { this.keys.set(keyIndex, key); this.values.set(keyIndex, value); } else { this.keys.add(key); this.values.add(value); this.indexMap.put(key, new Integer(this.keys.size() - 1)); } } /** * Inserts a new value at the specified position in the dataset or, if * there is an existing item with the specified key, updates the value * for that item and moves it to the specified position. * * @param position the position (in the range 0 to getItemCount()). * @param key the key (<code>null</code> not permitted). * @param value the value. * * @since 1.0.6 */ public void insertValue(int position, Comparable key, double value) { insertValue(position, key, new Double(value)); } /** * Inserts a new value at the specified position in the dataset or, if * there is an existing item with the specified key, updates the value * for that item and moves it to the specified position. * * @param position the position (in the range 0 to getItemCount()). * @param key the key (<code>null</code> not permitted). * @param value the value (<code>null</code> permitted). * * @since 1.0.6 */ public void insertValue(int position, Comparable key, Number value) { if (position < 0 || position > getItemCount()) { throw new IllegalArgumentException("'position' out of bounds."); } ParamChecks.nullNotPermitted(key, "key"); int pos = getIndex(key); if (pos == position) { this.keys.set(pos, key); this.values.set(pos, value); } else { if (pos >= 0) { this.keys.remove(pos); this.values.remove(pos); } this.keys.add(position, key); this.values.add(position, value); rebuildIndex(); } } /** * Rebuilds the key to indexed-position mapping after an positioned insert * or a remove operation. */ private void rebuildIndex() { this.indexMap.clear(); for (int i = 0; i < this.keys.size(); i++) { final Object key = this.keys.get(i); this.indexMap.put(key, new Integer(i)); } } /** * Removes a value from the collection. * * @param index the index of the item to remove (in the range * <code>0</code> to <code>getItemCount() - 1</code>). * * @throws IndexOutOfBoundsException if <code>index</code> is not within * the specified range. */ public void removeValue(int index) { this.keys.remove(index); this.values.remove(index); rebuildIndex(); } /** * Removes a value from the collection. * * @param key the item key (<code>null</code> not permitted). * * @throws IllegalArgumentException if <code>key</code> is * <code>null</code>. * @throws UnknownKeyException if <code>key</code> is not recognised. */ public void removeValue(Comparable key) { int index = getIndex(key); if (index < 0) { throw new UnknownKeyException("The key (" + key + ") is not recognised."); } removeValue(index); } /** * Clears all values from the collection. * * @since 1.0.2 */ public void clear() { this.keys.clear(); this.values.clear(); this.indexMap.clear(); } /** * Sorts the items in the list by key. * * @param order the sort order (<code>null</code> not permitted). */ public void sortByKeys(SortOrder order) { final int size = this.keys.size(); final DefaultKeyedValue[] data = new DefaultKeyedValue[size]; for (int i = 0; i < size; i++) { data[i] = new DefaultKeyedValue((Comparable) this.keys.get(i), (Number) this.values.get(i)); } Comparator comparator = new KeyedValueComparator(KeyedValueComparatorType.BY_KEY, order); Arrays.sort(data, comparator); clear(); for (int i = 0; i < data.length; i++) { final DefaultKeyedValue value = data[i]; addValue(value.getKey(), value.getValue()); } } /** * Sorts the items in the list by value. If the list contains * <code>null</code> values, they will sort to the end of the list, * irrespective of the sort order. * * @param order the sort order (<code>null</code> not permitted). */ public void sortByValues(SortOrder order) { final int size = this.keys.size(); final DefaultKeyedValue[] data = new DefaultKeyedValue[size]; for (int i = 0; i < size; i++) { data[i] = new DefaultKeyedValue((Comparable) this.keys.get(i), (Number) this.values.get(i)); } Comparator comparator = new KeyedValueComparator(KeyedValueComparatorType.BY_VALUE, order); Arrays.sort(data, comparator); clear(); for (int i = 0; i < data.length; i++) { final DefaultKeyedValue value = data[i]; addValue(value.getKey(), value.getValue()); } } /** * Tests if this object is equal to another. * * @param obj the object (<code>null</code> permitted). * * @return A boolean. */ @Override public boolean equals(Object obj) { if (obj == this) { return true; } if (!(obj instanceof KeyedValues)) { return false; } KeyedValues that = (KeyedValues) obj; int count = getItemCount(); if (count != that.getItemCount()) { return false; } for (int i = 0; i < count; i++) { Comparable k1 = getKey(i); Comparable k2 = that.getKey(i); if (!k1.equals(k2)) { return false; } Number v1 = getValue(i); Number v2 = that.getValue(i); if (v1 == null) { if (v2 != null) { return false; } } else { if (!v1.equals(v2)) { return false; } } } return true; } /** * Returns a hash code. * * @return A hash code. */ @Override public int hashCode() { return (this.keys != null ? this.keys.hashCode() : 0); } /** * Returns a clone. * * @return A clone. * * @throws CloneNotSupportedException this class will not throw this * exception, but subclasses might. */ @Override public Object clone() throws CloneNotSupportedException { DefaultKeyedValues clone = (DefaultKeyedValues) super.clone(); clone.keys = (ArrayList) this.keys.clone(); clone.values = (ArrayList) this.values.clone(); clone.indexMap = (HashMap) this.indexMap.clone(); return clone; } }