Java tutorial
import java.awt.Shape; import java.awt.geom.Arc2D; import java.awt.geom.Ellipse2D; import java.awt.geom.GeneralPath; import java.awt.geom.Line2D; import java.awt.geom.PathIterator; import java.awt.geom.Rectangle2D; import java.io.IOException; import java.io.ObjectInputStream; import java.io.ObjectOutputStream; import java.io.Serializable; /* * JCommon : a free general purpose class library for the Java(tm) platform * * * (C) Copyright 2000-2005, by Object Refinery Limited and Contributors. * * Project Info: http://www.jfree.org/jcommon/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. * * [Java is a trademark or registered trademark of Sun Microsystems, Inc. * in the United States and other countries.] * * ------------ * IOUtils.java * ------------ * (C)opyright 2002-2004, by Thomas Morgner and Contributors. * * Original Author: Thomas Morgner; * Contributor(s): David Gilbert (for Object Refinery Limited); * * $Id: IOUtils.java,v 1.8 2009/01/22 08:34:58 taqua Exp $ * * Changes * ------- * 26-Jan-2003 : Initial version * 23-Feb-2003 : Documentation * 25-Feb-2003 : Fixed Checkstyle issues (DG); * 29-Apr-2003 : Moved to jcommon * 04-Jan-2004 : Fixed JDK 1.2.2 issues with createRelativeURL; * added support for query strings within these urls (TM); */ public class Main { /** * Returns <code>true</code> if a class implements <code>Serializable</code> * and <code>false</code> otherwise. * * @param c the class. * * @return A boolean. */ public static boolean isSerializable(final Class c) { /** final Class[] interfaces = c.getInterfaces(); for (int i = 0; i < interfaces.length; i++) { if (interfaces[i].equals(Serializable.class)) { return true; } } Class cc = c.getSuperclass(); if (cc != null) { return isSerializable(cc); } */ return (Serializable.class.isAssignableFrom(c)); } /** * Reads a <code>Shape</code> object that has been serialised by the * {@link #writeShape(Shape, ObjectOutputStream)} method. * * @param stream the input stream (<code>null</code> not permitted). * * @return The shape object (possibly <code>null</code>). * * @throws IOException if there is an I/O problem. * @throws ClassNotFoundException if there is a problem loading a class. */ public static Shape readShape(final ObjectInputStream stream) throws IOException, ClassNotFoundException { if (stream == null) { throw new IllegalArgumentException("Null 'stream' argument."); } Shape result = null; final boolean isNull = stream.readBoolean(); if (!isNull) { final Class c = (Class) stream.readObject(); if (c.equals(Line2D.class)) { final double x1 = stream.readDouble(); final double y1 = stream.readDouble(); final double x2 = stream.readDouble(); final double y2 = stream.readDouble(); result = new Line2D.Double(x1, y1, x2, y2); } else if (c.equals(Rectangle2D.class)) { final double x = stream.readDouble(); final double y = stream.readDouble(); final double w = stream.readDouble(); final double h = stream.readDouble(); result = new Rectangle2D.Double(x, y, w, h); } else if (c.equals(Ellipse2D.class)) { final double x = stream.readDouble(); final double y = stream.readDouble(); final double w = stream.readDouble(); final double h = stream.readDouble(); result = new Ellipse2D.Double(x, y, w, h); } else if (c.equals(Arc2D.class)) { final double x = stream.readDouble(); final double y = stream.readDouble(); final double w = stream.readDouble(); final double h = stream.readDouble(); final double as = stream.readDouble(); // Angle Start final double ae = stream.readDouble(); // Angle Extent final int at = stream.readInt(); // Arc type result = new Arc2D.Double(x, y, w, h, as, ae, at); } else if (c.equals(GeneralPath.class)) { final GeneralPath gp = new GeneralPath(); final float[] args = new float[6]; boolean hasNext = stream.readBoolean(); while (!hasNext) { final int type = stream.readInt(); for (int i = 0; i < 6; i++) { args[i] = stream.readFloat(); } switch (type) { case PathIterator.SEG_MOVETO: gp.moveTo(args[0], args[1]); break; case PathIterator.SEG_LINETO: gp.lineTo(args[0], args[1]); break; case PathIterator.SEG_CUBICTO: gp.curveTo(args[0], args[1], args[2], args[3], args[4], args[5]); break; case PathIterator.SEG_QUADTO: gp.quadTo(args[0], args[1], args[2], args[3]); break; case PathIterator.SEG_CLOSE: gp.closePath(); break; default: throw new RuntimeException("JFreeChart - No path exists"); } gp.setWindingRule(stream.readInt()); hasNext = stream.readBoolean(); } result = gp; } else { result = (Shape) stream.readObject(); } } return result; } /** * Serialises a <code>Shape</code> object. * * @param shape the shape object (<code>null</code> permitted). * @param stream the output stream (<code>null</code> not permitted). * * @throws IOException if there is an I/O error. */ public static void writeShape(final Shape shape, final ObjectOutputStream stream) throws IOException { if (stream == null) { throw new IllegalArgumentException("Null 'stream' argument."); } if (shape != null) { stream.writeBoolean(false); if (shape instanceof Line2D) { final Line2D line = (Line2D) shape; stream.writeObject(Line2D.class); stream.writeDouble(line.getX1()); stream.writeDouble(line.getY1()); stream.writeDouble(line.getX2()); stream.writeDouble(line.getY2()); } else if (shape instanceof Rectangle2D) { final Rectangle2D rectangle = (Rectangle2D) shape; stream.writeObject(Rectangle2D.class); stream.writeDouble(rectangle.getX()); stream.writeDouble(rectangle.getY()); stream.writeDouble(rectangle.getWidth()); stream.writeDouble(rectangle.getHeight()); } else if (shape instanceof Ellipse2D) { final Ellipse2D ellipse = (Ellipse2D) shape; stream.writeObject(Ellipse2D.class); stream.writeDouble(ellipse.getX()); stream.writeDouble(ellipse.getY()); stream.writeDouble(ellipse.getWidth()); stream.writeDouble(ellipse.getHeight()); } else if (shape instanceof Arc2D) { final Arc2D arc = (Arc2D) shape; stream.writeObject(Arc2D.class); stream.writeDouble(arc.getX()); stream.writeDouble(arc.getY()); stream.writeDouble(arc.getWidth()); stream.writeDouble(arc.getHeight()); stream.writeDouble(arc.getAngleStart()); stream.writeDouble(arc.getAngleExtent()); stream.writeInt(arc.getArcType()); } else if (shape instanceof GeneralPath) { stream.writeObject(GeneralPath.class); final PathIterator pi = shape.getPathIterator(null); final float[] args = new float[6]; stream.writeBoolean(pi.isDone()); while (!pi.isDone()) { final int type = pi.currentSegment(args); stream.writeInt(type); // TODO: could write this to only stream the values // required for the segment type for (int i = 0; i < 6; i++) { stream.writeFloat(args[i]); } stream.writeInt(pi.getWindingRule()); pi.next(); stream.writeBoolean(pi.isDone()); } } else { stream.writeObject(shape.getClass()); stream.writeObject(shape); } } else { stream.writeBoolean(true); } } }