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.] * * ------------------ * KeyedObject2D.java * ------------------ * (C) Copyright 2003-2013, by Object Refinery Limited. * * Original Author: David Gilbert (for Object Refinery Limited); * Contributor(s): -; * * Changes * ------- * 05-Feb-2003 : Version 1 (DG); * 01-Mar-2004 : Added equals() and clone() methods and implemented * Serializable (DG); * 03-Oct-2007 : Updated getObject() to handle modified behaviour in * KeyedObjects class, added clear() method (DG); * 03-Jul-2013 : Use ParamChecks (DG); * */ package org.jfree.data; import java.io.Serializable; import java.util.Collections; import java.util.Iterator; import java.util.List; import org.jfree.chart.util.ParamChecks; /** * A data structure that stores zero, one or many objects, where each object is * associated with two keys (a 'row' key and a 'column' key). */ public class KeyedObjects2D implements Cloneable, Serializable { /** For serialization. */ private static final long serialVersionUID = -1015873563138522374L; /** The row keys. */ private List rowKeys; /** The column keys. */ private List columnKeys; /** The row data. */ private List rows; /** * Creates a new instance (initially empty). */ public KeyedObjects2D() { this.rowKeys = new java.util.ArrayList(); this.columnKeys = new java.util.ArrayList(); this.rows = new java.util.ArrayList(); } /** * Returns the row count. * * @return The row count. * * @see #getColumnCount() */ public int getRowCount() { return this.rowKeys.size(); } /** * Returns the column count. * * @return The column count. * * @see #getRowCount() */ public int getColumnCount() { return this.columnKeys.size(); } /** * Returns the object for a given row and column. * * @param row the row index (in the range 0 to getRowCount() - 1). * @param column the column index (in the range 0 to getColumnCount() - 1). * * @return The object (possibly <code>null</code>). * * @see #getObject(Comparable, Comparable) */ public Object getObject(int row, int column) { Object result = null; KeyedObjects rowData = (KeyedObjects) this.rows.get(row); if (rowData != null) { Comparable columnKey = (Comparable) this.columnKeys.get(column); if (columnKey != null) { int index = rowData.getIndex(columnKey); if (index >= 0) { result = rowData.getObject(columnKey); } } } return result; } /** * Returns the key for a given row. * * @param row the row index (zero based). * * @return The row index. * * @see #getRowIndex(Comparable) */ public Comparable getRowKey(int row) { return (Comparable) this.rowKeys.get(row); } /** * Returns the row index for a given key, or <code>-1</code> if the key * is not recognised. * * @param key the key (<code>null</code> not permitted). * * @return The row index. * * @see #getRowKey(int) */ public int getRowIndex(Comparable key) { ParamChecks.nullNotPermitted(key, "key"); return this.rowKeys.indexOf(key); } /** * Returns the row keys. * * @return The row keys (never <code>null</code>). * * @see #getRowKeys() */ public List getRowKeys() { return Collections.unmodifiableList(this.rowKeys); } /** * Returns the key for a given column. * * @param column the column. * * @return The key. * * @see #getColumnIndex(Comparable) */ public Comparable getColumnKey(int column) { return (Comparable) this.columnKeys.get(column); } /** * Returns the column index for a given key, or <code>-1</code> if the key * is not recognised. * * @param key the key (<code>null</code> not permitted). * * @return The column index. * * @see #getColumnKey(int) */ public int getColumnIndex(Comparable key) { ParamChecks.nullNotPermitted(key, "key"); return this.columnKeys.indexOf(key); } /** * Returns the column keys. * * @return The column keys (never <code>null</code>). * * @see #getRowKeys() */ public List getColumnKeys() { return Collections.unmodifiableList(this.columnKeys); } /** * Returns the object for the given row and column keys. * * @param rowKey the row key (<code>null</code> not permitted). * @param columnKey the column key (<code>null</code> not permitted). * * @return The object (possibly <code>null</code>). * * @throws IllegalArgumentException if <code>rowKey</code> or * <code>columnKey</code> is <code>null</code>. * @throws UnknownKeyException if <code>rowKey</code> or * <code>columnKey</code> is not recognised. */ public Object getObject(Comparable rowKey, Comparable columnKey) { ParamChecks.nullNotPermitted(rowKey, "rowKey"); ParamChecks.nullNotPermitted(columnKey, "columnKey"); int row = this.rowKeys.indexOf(rowKey); if (row < 0) { throw new UnknownKeyException("Row key (" + rowKey + ") not recognised."); } int column = this.columnKeys.indexOf(columnKey); if (column < 0) { throw new UnknownKeyException("Column key (" + columnKey + ") not recognised."); } KeyedObjects rowData = (KeyedObjects) this.rows.get(row); int index = rowData.getIndex(columnKey); if (index >= 0) { return rowData.getObject(index); } else { return null; } } /** * Adds an object to the table. Performs the same function as setObject(). * * @param object the object. * @param rowKey the row key (<code>null</code> not permitted). * @param columnKey the column key (<code>null</code> not permitted). */ public void addObject(Object object, Comparable rowKey, Comparable columnKey) { setObject(object, rowKey, columnKey); } /** * Adds or updates an object. * * @param object the object. * @param rowKey the row key (<code>null</code> not permitted). * @param columnKey the column key (<code>null</code> not permitted). */ public void setObject(Object object, Comparable rowKey, Comparable columnKey) { ParamChecks.nullNotPermitted(rowKey, "rowKey"); ParamChecks.nullNotPermitted(columnKey, "columnKey"); KeyedObjects row; int rowIndex = this.rowKeys.indexOf(rowKey); if (rowIndex >= 0) { row = (KeyedObjects) this.rows.get(rowIndex); } else { this.rowKeys.add(rowKey); row = new KeyedObjects(); this.rows.add(row); } row.setObject(columnKey, object); int columnIndex = this.columnKeys.indexOf(columnKey); if (columnIndex < 0) { this.columnKeys.add(columnKey); } } /** * Removes an object from the table by setting it to <code>null</code>. If * all the objects in the specified row and/or column are now * <code>null</code>, the row and/or column is removed from the table. * * @param rowKey the row key (<code>null</code> not permitted). * @param columnKey the column key (<code>null</code> not permitted). * * @see #addObject(Object, Comparable, Comparable) */ public void removeObject(Comparable rowKey, Comparable columnKey) { int rowIndex = getRowIndex(rowKey); if (rowIndex < 0) { throw new UnknownKeyException("Row key (" + rowKey + ") not recognised."); } int columnIndex = getColumnIndex(columnKey); if (columnIndex < 0) { throw new UnknownKeyException("Column key (" + columnKey + ") not recognised."); } setObject(null, rowKey, columnKey); // 1. check whether the row is now empty. boolean allNull = true; KeyedObjects row = (KeyedObjects) this.rows.get(rowIndex); for (int item = 0, itemCount = row.getItemCount(); item < itemCount; item++) { if (row.getObject(item) != null) { allNull = false; break; } } if (allNull) { this.rowKeys.remove(rowIndex); this.rows.remove(rowIndex); } // 2. check whether the column is now empty. allNull = true; for (int item = 0, itemCount = this.rows.size(); item < itemCount; item++) { row = (KeyedObjects) this.rows.get(item); int colIndex = row.getIndex(columnKey); if (colIndex >= 0 && row.getObject(colIndex) != null) { allNull = false; break; } } if (allNull) { for (int item = 0, itemCount = this.rows.size(); item < itemCount; item++) { row = (KeyedObjects) this.rows.get(item); int colIndex = row.getIndex(columnKey); if (colIndex >= 0) { row.removeValue(colIndex); } } this.columnKeys.remove(columnKey); } } /** * Removes an entire row from the table. * * @param rowIndex the row index. * * @see #removeColumn(int) */ public void removeRow(int rowIndex) { this.rowKeys.remove(rowIndex); this.rows.remove(rowIndex); } /** * Removes an entire row from the table. * * @param rowKey the row key (<code>null</code> not permitted). * * @throws UnknownKeyException if <code>rowKey</code> is not recognised. * * @see #removeColumn(Comparable) */ public void removeRow(Comparable rowKey) { int index = getRowIndex(rowKey); if (index < 0) { throw new UnknownKeyException("Row key (" + rowKey + ") not recognised."); } removeRow(index); } /** * Removes an entire column from the table. * * @param columnIndex the column index. * * @see #removeRow(int) */ public void removeColumn(int columnIndex) { Comparable columnKey = getColumnKey(columnIndex); removeColumn(columnKey); } /** * Removes an entire column from the table. * * @param columnKey the column key (<code>null</code> not permitted). * * @throws UnknownKeyException if <code>rowKey</code> is not recognised. * * @see #removeRow(Comparable) */ public void removeColumn(Comparable columnKey) { int index = getColumnIndex(columnKey); if (index < 0) { throw new UnknownKeyException("Column key (" + columnKey + ") not recognised."); } Iterator iterator = this.rows.iterator(); while (iterator.hasNext()) { KeyedObjects rowData = (KeyedObjects) iterator.next(); int i = rowData.getIndex(columnKey); if (i >= 0) { rowData.removeValue(i); } } this.columnKeys.remove(columnKey); } /** * Clears all the data and associated keys. * * @since 1.0.7 */ public void clear() { this.rowKeys.clear(); this.columnKeys.clear(); this.rows.clear(); } /** * Tests this object for equality with an arbitrary object. * * @param obj the object to test (<code>null</code> permitted). * * @return A boolean. */ @Override public boolean equals(Object obj) { if (obj == this) { return true; } if (!(obj instanceof KeyedObjects2D)) { return false; } KeyedObjects2D that = (KeyedObjects2D) obj; if (!getRowKeys().equals(that.getRowKeys())) { return false; } if (!getColumnKeys().equals(that.getColumnKeys())) { return false; } int rowCount = getRowCount(); if (rowCount != that.getRowCount()) { return false; } int colCount = getColumnCount(); if (colCount != that.getColumnCount()) { return false; } for (int r = 0; r < rowCount; r++) { for (int c = 0; c < colCount; c++) { Object v1 = getObject(r, c); Object v2 = that.getObject(r, c); if (v1 == null) { if (v2 != null) { return false; } } else { if (!v1.equals(v2)) { return false; } } } } return true; } /** * Returns a hashcode for this object. * * @return A hashcode. */ @Override public int hashCode() { int result; result = this.rowKeys.hashCode(); result = 29 * result + this.columnKeys.hashCode(); result = 29 * result + this.rows.hashCode(); return result; } /** * Returns a clone. * * @return A clone. * * @throws CloneNotSupportedException this class will not throw this * exception, but subclasses (if any) might. */ @Override public Object clone() throws CloneNotSupportedException { KeyedObjects2D clone = (KeyedObjects2D) super.clone(); clone.columnKeys = new java.util.ArrayList(this.columnKeys); clone.rowKeys = new java.util.ArrayList(this.rowKeys); clone.rows = new java.util.ArrayList(this.rows.size()); Iterator iterator = this.rows.iterator(); while (iterator.hasNext()) { KeyedObjects row = (KeyedObjects) iterator.next(); clone.rows.add(row.clone()); } return clone; } }