https://openjdk.java.net/ 
/*
 * Copyright (c) 1997, 2017, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code 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 Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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 * questions.
 */

package java.awt.geom;

import java.awt.Shape;
import java.awt.Rectangle;
import java.io.Serializable;


This Line2D represents a line segment in (x,y) coordinate space. 

This class is only the abstract superclass for all objects that
store a 2D line segment.
The actual storage representation of the coordinates is left to
the subclass.

Author:     Jim Graham
Since:1.2
/**
 * This {@code Line2D} represents a line segment in {@code (x,y)}
 * coordinate space.
 * <p>
 * This class is only the abstract superclass for all objects that
 * store a 2D line segment.
 * The actual storage representation of the coordinates is left to
 * the subclass.
 *
 * @author      Jim Graham
 * @since 1.2
 */
public abstract class Line2D implements Shape, Cloneable {

    
A line segment specified with float coordinates.

Since:1.2
/**
     * A line segment specified with float coordinates.
     * @since 1.2
     */
    public static class Float extends Line2D implements Serializable {
        
The X coordinate of the start point of the line segment.

Since:1.2
@serial
/**
         * The X coordinate of the start point of the line segment.
         * @since 1.2
         * @serial
         */
        public float x1;

        
The Y coordinate of the start point of the line segment.

Since:1.2
@serial
/**
         * The Y coordinate of the start point of the line segment.
         * @since 1.2
         * @serial
         */
        public float y1;

        
The X coordinate of the end point of the line segment.

Since:1.2
@serial
/**
         * The X coordinate of the end point of the line segment.
         * @since 1.2
         * @serial
         */
        public float x2;

        
The Y coordinate of the end point of the line segment.

Since:1.2
@serial
/**
         * The Y coordinate of the end point of the line segment.
         * @since 1.2
         * @serial
         */
        public float y2;

        
Constructs and initializes a Line with coordinates (0, 0) → (0, 0).

Since:1.2
/**
         * Constructs and initializes a Line with coordinates (0, 0) &rarr; (0, 0).
         * @since 1.2
         */
        public Float() {
        }

        
Constructs and initializes a Line from the specified coordinates.

Params:
  • x1 – the X coordinate of the start point
  • y1 – the Y coordinate of the start point
  • x2 – the X coordinate of the end point
  • y2 – the Y coordinate of the end point
Since:1.2
/**
         * Constructs and initializes a Line from the specified coordinates.
         * @param x1 the X coordinate of the start point
         * @param y1 the Y coordinate of the start point
         * @param x2 the X coordinate of the end point
         * @param y2 the Y coordinate of the end point
         * @since 1.2
         */
        public Float(float x1, float y1, float x2, float y2) {
            setLine(x1, y1, x2, y2);
        }

        
Constructs and initializes a Line2D from the specified Point2D objects. 
Params:
  • p1 – the start Point2D of this line segment
  • p2 – the end Point2D of this line segment
Since:1.2
/**
         * Constructs and initializes a {@code Line2D} from the
         * specified {@code Point2D} objects.
         * @param p1 the start {@code Point2D} of this line segment
         * @param p2 the end {@code Point2D} of this line segment
         * @since 1.2
         */
        public Float(Point2D p1, Point2D p2) {
            setLine(p1, p2);
        }

        
{@inheritDoc}

Since:1.2
/**
         * {@inheritDoc}
         * @since 1.2
         */
        public double getX1() {
            return (double) x1;
        }

        
{@inheritDoc}

Since:1.2
/**
         * {@inheritDoc}
         * @since 1.2
         */
        public double getY1() {
            return (double) y1;
        }

        
{@inheritDoc}

Since:1.2
/**
         * {@inheritDoc}
         * @since 1.2
         */
        public Point2D getP1() {
            return new Point2D.Float(x1, y1);
        }

        
{@inheritDoc}

Since:1.2
/**
         * {@inheritDoc}
         * @since 1.2
         */
        public double getX2() {
            return (double) x2;
        }

        
{@inheritDoc}

Since:1.2
/**
         * {@inheritDoc}
         * @since 1.2
         */
        public double getY2() {
            return (double) y2;
        }

        
{@inheritDoc}

Since:1.2
/**
         * {@inheritDoc}
         * @since 1.2
         */
        public Point2D getP2() {
            return new Point2D.Float(x2, y2);
        }

        
{@inheritDoc}

Since:1.2
/**
         * {@inheritDoc}
         * @since 1.2
         */
        public void setLine(double x1, double y1, double x2, double y2) {
            this.x1 = (float) x1;
            this.y1 = (float) y1;
            this.x2 = (float) x2;
            this.y2 = (float) y2;
        }

        
Sets the location of the end points of this Line2D to the specified float coordinates. 
Params:
  • x1 – the X coordinate of the start point
  • y1 – the Y coordinate of the start point
  • x2 – the X coordinate of the end point
  • y2 – the Y coordinate of the end point
Since:1.2
/**
         * Sets the location of the end points of this {@code Line2D}
         * to the specified float coordinates.
         * @param x1 the X coordinate of the start point
         * @param y1 the Y coordinate of the start point
         * @param x2 the X coordinate of the end point
         * @param y2 the Y coordinate of the end point
         * @since 1.2
         */
        public void setLine(float x1, float y1, float x2, float y2) {
            this.x1 = x1;
            this.y1 = y1;
            this.x2 = x2;
            this.y2 = y2;
        }

        
{@inheritDoc}

Since:1.2
/**
         * {@inheritDoc}
         * @since 1.2
         */
        public Rectangle2D getBounds2D() {
            float x, y, w, h;
            if (x1 < x2) {
                x = x1;
                w = x2 - x1;
            } else {
                x = x2;
                w = x1 - x2;
            }
            if (y1 < y2) {
                y = y1;
                h = y2 - y1;
            } else {
                y = y2;
                h = y1 - y2;
            }
            return new Rectangle2D.Float(x, y, w, h);
        }

        /*
         * JDK 1.6 serialVersionUID
         */
        private static final long serialVersionUID = 6161772511649436349L;
    }

    
A line segment specified with double coordinates.

Since:1.2
/**
     * A line segment specified with double coordinates.
     * @since 1.2
     */
    public static class Double extends Line2D implements Serializable {
        
The X coordinate of the start point of the line segment.

Since:1.2
@serial
/**
         * The X coordinate of the start point of the line segment.
         * @since 1.2
         * @serial
         */
        public double x1;

        
The Y coordinate of the start point of the line segment.

Since:1.2
@serial
/**
         * The Y coordinate of the start point of the line segment.
         * @since 1.2
         * @serial
         */
        public double y1;

        
The X coordinate of the end point of the line segment.

Since:1.2
@serial
/**
         * The X coordinate of the end point of the line segment.
         * @since 1.2
         * @serial
         */
        public double x2;

        
The Y coordinate of the end point of the line segment.

Since:1.2
@serial
/**
         * The Y coordinate of the end point of the line segment.
         * @since 1.2
         * @serial
         */
        public double y2;

        
Constructs and initializes a Line with coordinates (0, 0) → (0, 0).

Since:1.2
/**
         * Constructs and initializes a Line with coordinates (0, 0) &rarr; (0, 0).
         * @since 1.2
         */
        public Double() {
        }

        
Constructs and initializes a Line2D from the specified coordinates. 
Params:
  • x1 – the X coordinate of the start point
  • y1 – the Y coordinate of the start point
  • x2 – the X coordinate of the end point
  • y2 – the Y coordinate of the end point
Since:1.2
/**
         * Constructs and initializes a {@code Line2D} from the
         * specified coordinates.
         * @param x1 the X coordinate of the start point
         * @param y1 the Y coordinate of the start point
         * @param x2 the X coordinate of the end point
         * @param y2 the Y coordinate of the end point
         * @since 1.2
         */
        public Double(double x1, double y1, double x2, double y2) {
            setLine(x1, y1, x2, y2);
        }

        
Constructs and initializes a Line2D from the specified Point2D objects. 
Params:
  • p1 – the start Point2D of this line segment
  • p2 – the end Point2D of this line segment
Since:1.2
/**
         * Constructs and initializes a {@code Line2D} from the
         * specified {@code Point2D} objects.
         * @param p1 the start {@code Point2D} of this line segment
         * @param p2 the end {@code Point2D} of this line segment
         * @since 1.2
         */
        public Double(Point2D p1, Point2D p2) {
            setLine(p1, p2);
        }

        
{@inheritDoc}

Since:1.2
/**
         * {@inheritDoc}
         * @since 1.2
         */
        public double getX1() {
            return x1;
        }

        
{@inheritDoc}

Since:1.2
/**
         * {@inheritDoc}
         * @since 1.2
         */
        public double getY1() {
            return y1;
        }

        
{@inheritDoc}

Since:1.2
/**
         * {@inheritDoc}
         * @since 1.2
         */
        public Point2D getP1() {
            return new Point2D.Double(x1, y1);
        }

        
{@inheritDoc}

Since:1.2
/**
         * {@inheritDoc}
         * @since 1.2
         */
        public double getX2() {
            return x2;
        }

        
{@inheritDoc}

Since:1.2
/**
         * {@inheritDoc}
         * @since 1.2
         */
        public double getY2() {
            return y2;
        }

        
{@inheritDoc}

Since:1.2
/**
         * {@inheritDoc}
         * @since 1.2
         */
        public Point2D getP2() {
            return new Point2D.Double(x2, y2);
        }

        
{@inheritDoc}

Since:1.2
/**
         * {@inheritDoc}
         * @since 1.2
         */
        public void setLine(double x1, double y1, double x2, double y2) {
            this.x1 = x1;
            this.y1 = y1;
            this.x2 = x2;
            this.y2 = y2;
        }

        
{@inheritDoc}

Since:1.2
/**
         * {@inheritDoc}
         * @since 1.2
         */
        public Rectangle2D getBounds2D() {
            double x, y, w, h;
            if (x1 < x2) {
                x = x1;
                w = x2 - x1;
            } else {
                x = x2;
                w = x1 - x2;
            }
            if (y1 < y2) {
                y = y1;
                h = y2 - y1;
            } else {
                y = y2;
                h = y1 - y2;
            }
            return new Rectangle2D.Double(x, y, w, h);
        }

        /*
         * JDK 1.6 serialVersionUID
         */
        private static final long serialVersionUID = 7979627399746467499L;
    }

    
This is an abstract class that cannot be instantiated directly.
Type-specific implementation subclasses are available for
instantiation and provide a number of formats for storing
the information necessary to satisfy the various accessory
methods below.

See Also:
Since:1.2
/**
     * This is an abstract class that cannot be instantiated directly.
     * Type-specific implementation subclasses are available for
     * instantiation and provide a number of formats for storing
     * the information necessary to satisfy the various accessory
     * methods below.
     *
     * @see java.awt.geom.Line2D.Float
     * @see java.awt.geom.Line2D.Double
     * @since 1.2
     */
    protected Line2D() {
    }

    
Returns the X coordinate of the start point in double precision.

Returns:the X coordinate of the start point of this Line2D object.
Since:1.2
/**
     * Returns the X coordinate of the start point in double precision.
     * @return the X coordinate of the start point of this
     *         {@code Line2D} object.
     * @since 1.2
     */
    public abstract double getX1();

    
Returns the Y coordinate of the start point in double precision.

Returns:the Y coordinate of the start point of this Line2D object.
Since:1.2
/**
     * Returns the Y coordinate of the start point in double precision.
     * @return the Y coordinate of the start point of this
     *         {@code Line2D} object.
     * @since 1.2
     */
    public abstract double getY1();

    
Returns the start Point2D of this Line2D. 
Returns:the start Point2D of this Line2D.
Since:1.2
/**
     * Returns the start {@code Point2D} of this {@code Line2D}.
     * @return the start {@code Point2D} of this {@code Line2D}.
     * @since 1.2
     */
    public abstract Point2D getP1();

    
Returns the X coordinate of the end point in double precision.

Returns:the X coordinate of the end point of this Line2D object.
Since:1.2
/**
     * Returns the X coordinate of the end point in double precision.
     * @return the X coordinate of the end point of this
     *         {@code Line2D} object.
     * @since 1.2
     */
    public abstract double getX2();

    
Returns the Y coordinate of the end point in double precision.

Returns:the Y coordinate of the end point of this Line2D object.
Since:1.2
/**
     * Returns the Y coordinate of the end point in double precision.
     * @return the Y coordinate of the end point of this
     *         {@code Line2D} object.
     * @since 1.2
     */
    public abstract double getY2();

    
Returns the end Point2D of this Line2D. 
Returns:the end Point2D of this Line2D.
Since:1.2
/**
     * Returns the end {@code Point2D} of this {@code Line2D}.
     * @return the end {@code Point2D} of this {@code Line2D}.
     * @since 1.2
     */
    public abstract Point2D getP2();

    
Sets the location of the end points of this Line2D to the specified double coordinates. 
Params:
  • x1 – the X coordinate of the start point
  • y1 – the Y coordinate of the start point
  • x2 – the X coordinate of the end point
  • y2 – the Y coordinate of the end point
Since:1.2
/**
     * Sets the location of the end points of this {@code Line2D} to
     * the specified double coordinates.
     * @param x1 the X coordinate of the start point
     * @param y1 the Y coordinate of the start point
     * @param x2 the X coordinate of the end point
     * @param y2 the Y coordinate of the end point
     * @since 1.2
     */
    public abstract void setLine(double x1, double y1, double x2, double y2);

    
Sets the location of the end points of this Line2D to the specified Point2D coordinates. 
Params:
  • p1 – the start Point2D of the line segment
  • p2 – the end Point2D of the line segment
Since:1.2
/**
     * Sets the location of the end points of this {@code Line2D} to
     * the specified {@code Point2D} coordinates.
     * @param p1 the start {@code Point2D} of the line segment
     * @param p2 the end {@code Point2D} of the line segment
     * @since 1.2
     */
    public void setLine(Point2D p1, Point2D p2) {
        setLine(p1.getX(), p1.getY(), p2.getX(), p2.getY());
    }

    
Sets the location of the end points of this Line2D to the same as those end points of the specified Line2D. 
Params:
  • l – the specified Line2D
Since:1.2
/**
     * Sets the location of the end points of this {@code Line2D} to
     * the same as those end points of the specified {@code Line2D}.
     * @param l the specified {@code Line2D}
     * @since 1.2
     */
    public void setLine(Line2D l) {
        setLine(l.getX1(), l.getY1(), l.getX2(), l.getY2());
    }

    
Returns an indicator of where the specified point (px,py) lies with respect to the line segment from (x1,y1) to (x2,y2). The return value can be either 1, -1, or 0 and indicates in which direction the specified line must pivot around its first end point, (x1,y1), in order to point at the specified point (px,py). 
A return value of 1 indicates that the line segment must
turn in the direction that takes the positive X axis towards
the negative Y axis.  In the default coordinate system used by
Java 2D, this direction is counterclockwise.

A return value of -1 indicates that the line segment must
turn in the direction that takes the positive X axis towards
the positive Y axis.  In the default coordinate system, this
direction is clockwise.

A return value of 0 indicates that the point lies
exactly on the line segment.  Note that an indicator value
of 0 is rare and not useful for determining collinearity
because of floating point rounding issues.

If the point is colinear with the line segment, but not between the end points, then the value will be -1 if the point lies "beyond (x1,y1)" or 1 if the point lies "beyond (x2,y2)". 
Params:
  • x1 – the X coordinate of the start point of the
          specified line segment
  • y1 – the Y coordinate of the start point of the
          specified line segment
  • x2 – the X coordinate of the end point of the
          specified line segment
  • y2 – the Y coordinate of the end point of the
          specified line segment
  • px – the X coordinate of the specified point to be
          compared with the specified line segment
  • py – the Y coordinate of the specified point to be
          compared with the specified line segment
Returns:an integer that indicates the position of the third specified
                 coordinates with respect to the line segment formed
                 by the first two specified coordinates.
Since:1.2
/**
     * Returns an indicator of where the specified point
     * {@code (px,py)} lies with respect to the line segment from
     * {@code (x1,y1)} to {@code (x2,y2)}.
     * The return value can be either 1, -1, or 0 and indicates
     * in which direction the specified line must pivot around its
     * first end point, {@code (x1,y1)}, in order to point at the
     * specified point {@code (px,py)}.
     * <p>A return value of 1 indicates that the line segment must
     * turn in the direction that takes the positive X axis towards
     * the negative Y axis.  In the default coordinate system used by
     * Java 2D, this direction is counterclockwise.
     * <p>A return value of -1 indicates that the line segment must
     * turn in the direction that takes the positive X axis towards
     * the positive Y axis.  In the default coordinate system, this
     * direction is clockwise.
     * <p>A return value of 0 indicates that the point lies
     * exactly on the line segment.  Note that an indicator value
     * of 0 is rare and not useful for determining collinearity
     * because of floating point rounding issues.
     * <p>If the point is colinear with the line segment, but
     * not between the end points, then the value will be -1 if the point
     * lies "beyond {@code (x1,y1)}" or 1 if the point lies
     * "beyond {@code (x2,y2)}".
     *
     * @param x1 the X coordinate of the start point of the
     *           specified line segment
     * @param y1 the Y coordinate of the start point of the
     *           specified line segment
     * @param x2 the X coordinate of the end point of the
     *           specified line segment
     * @param y2 the Y coordinate of the end point of the
     *           specified line segment
     * @param px the X coordinate of the specified point to be
     *           compared with the specified line segment
     * @param py the Y coordinate of the specified point to be
     *           compared with the specified line segment
     * @return an integer that indicates the position of the third specified
     *                  coordinates with respect to the line segment formed
     *                  by the first two specified coordinates.
     * @since 1.2
     */
    public static int relativeCCW(double x1, double y1,
                                  double x2, double y2,
                                  double px, double py)
    {
        x2 -= x1;
        y2 -= y1;
        px -= x1;
        py -= y1;
        double ccw = px * y2 - py * x2;
        if (ccw == 0.0) {
            // The point is colinear, classify based on which side of
            // the segment the point falls on.  We can calculate a
            // relative value using the projection of px,py onto the
            // segment - a negative value indicates the point projects
            // outside of the segment in the direction of the particular
            // endpoint used as the origin for the projection.
            ccw = px * x2 + py * y2;
            if (ccw > 0.0) {
                // Reverse the projection to be relative to the original x2,y2
                // x2 and y2 are simply negated.
                // px and py need to have (x2 - x1) or (y2 - y1) subtracted
                //    from them (based on the original values)
                // Since we really want to get a positive answer when the
                //    point is "beyond (x2,y2)", then we want to calculate
                //    the inverse anyway - thus we leave x2 & y2 negated.
                px -= x2;
                py -= y2;
                ccw = px * x2 + py * y2;
                if (ccw < 0.0) {
                    ccw = 0.0;
                }
            }
        }
        return (ccw < 0.0) ? -1 : ((ccw > 0.0) ? 1 : 0);
    }

    
Returns an indicator of where the specified point (px,py) lies with respect to this line segment. See the method comments of relativeCCW(double, double, double, double, double, double) to interpret the return value. 
Params:
  • px – the X coordinate of the specified point to be compared with this Line2D
  • py – the Y coordinate of the specified point to be compared with this Line2D
See Also:
Returns:an integer that indicates the position of the specified coordinates with respect to this Line2D
Since:1.2
/**
     * Returns an indicator of where the specified point
     * {@code (px,py)} lies with respect to this line segment.
     * See the method comments of
     * {@link #relativeCCW(double, double, double, double, double, double)}
     * to interpret the return value.
     * @param px the X coordinate of the specified point
     *           to be compared with this {@code Line2D}
     * @param py the Y coordinate of the specified point
     *           to be compared with this {@code Line2D}
     * @return an integer that indicates the position of the specified
     *         coordinates with respect to this {@code Line2D}
     * @see #relativeCCW(double, double, double, double, double, double)
     * @since 1.2
     */
    public int relativeCCW(double px, double py) {
        return relativeCCW(getX1(), getY1(), getX2(), getY2(), px, py);
    }

    
Returns an indicator of where the specified Point2D lies with respect to this line segment. See the method comments of relativeCCW(double, double, double, double, double, double) to interpret the return value. 
Params:
  • p – the specified Point2D to be compared with this Line2D
See Also:
Returns:an integer that indicates the position of the specified Point2D with respect to this Line2D
Since:1.2
/**
     * Returns an indicator of where the specified {@code Point2D}
     * lies with respect to this line segment.
     * See the method comments of
     * {@link #relativeCCW(double, double, double, double, double, double)}
     * to interpret the return value.
     * @param p the specified {@code Point2D} to be compared
     *          with this {@code Line2D}
     * @return an integer that indicates the position of the specified
     *         {@code Point2D} with respect to this {@code Line2D}
     * @see #relativeCCW(double, double, double, double, double, double)
     * @since 1.2
     */
    public int relativeCCW(Point2D p) {
        return relativeCCW(getX1(), getY1(), getX2(), getY2(),
                           p.getX(), p.getY());
    }

    
Tests if the line segment from (x1,y1) to (x2,y2) intersects the line segment from (x3,y3) to (x4,y4). 
Params:
  • x1 – the X coordinate of the start point of the first
          specified line segment
  • y1 – the Y coordinate of the start point of the first
          specified line segment
  • x2 – the X coordinate of the end point of the first
          specified line segment
  • y2 – the Y coordinate of the end point of the first
          specified line segment
  • x3 – the X coordinate of the start point of the second
          specified line segment
  • y3 – the Y coordinate of the start point of the second
          specified line segment
  • x4 – the X coordinate of the end point of the second
          specified line segment
  • y4 – the Y coordinate of the end point of the second
          specified line segment
Returns:true if the first specified line segment and the second specified line segment intersect each other; false otherwise.
Since:1.2
/**
     * Tests if the line segment from {@code (x1,y1)} to
     * {@code (x2,y2)} intersects the line segment from {@code (x3,y3)}
     * to {@code (x4,y4)}.
     *
     * @param x1 the X coordinate of the start point of the first
     *           specified line segment
     * @param y1 the Y coordinate of the start point of the first
     *           specified line segment
     * @param x2 the X coordinate of the end point of the first
     *           specified line segment
     * @param y2 the Y coordinate of the end point of the first
     *           specified line segment
     * @param x3 the X coordinate of the start point of the second
     *           specified line segment
     * @param y3 the Y coordinate of the start point of the second
     *           specified line segment
     * @param x4 the X coordinate of the end point of the second
     *           specified line segment
     * @param y4 the Y coordinate of the end point of the second
     *           specified line segment
     * @return {@code true} if the first specified line segment
     *                  and the second specified line segment intersect
     *                  each other; {@code false} otherwise.
     * @since 1.2
     */
    public static boolean linesIntersect(double x1, double y1,
                                         double x2, double y2,
                                         double x3, double y3,
                                         double x4, double y4)
    {
        return ((relativeCCW(x1, y1, x2, y2, x3, y3) *
                 relativeCCW(x1, y1, x2, y2, x4, y4) <= 0)
                && (relativeCCW(x3, y3, x4, y4, x1, y1) *
                    relativeCCW(x3, y3, x4, y4, x2, y2) <= 0));
    }

    
Tests if the line segment from (x1,y1) to (x2,y2) intersects this line segment. 
Params:
  • x1 – the X coordinate of the start point of the
          specified line segment
  • y1 – the Y coordinate of the start point of the
          specified line segment
  • x2 – the X coordinate of the end point of the
          specified line segment
  • y2 – the Y coordinate of the end point of the
          specified line segment
Returns:true if this line segment and the specified line segment intersect each other; false otherwise.
Since:1.2
/**
     * Tests if the line segment from {@code (x1,y1)} to
     * {@code (x2,y2)} intersects this line segment.
     *
     * @param x1 the X coordinate of the start point of the
     *           specified line segment
     * @param y1 the Y coordinate of the start point of the
     *           specified line segment
     * @param x2 the X coordinate of the end point of the
     *           specified line segment
     * @param y2 the Y coordinate of the end point of the
     *           specified line segment
     * @return {@code true} if this line segment and the specified line segment
     *                  intersect each other; {@code false} otherwise.
     * @since 1.2
     */
    public boolean intersectsLine(double x1, double y1, double x2, double y2) {
        return linesIntersect(x1, y1, x2, y2,
                              getX1(), getY1(), getX2(), getY2());
    }

    
Tests if the specified line segment intersects this line segment.

Params:
  • l – the specified Line2D
Returns:true if this line segment and the specified line segment intersect each other; false otherwise.
Since:1.2
/**
     * Tests if the specified line segment intersects this line segment.
     * @param l the specified {@code Line2D}
     * @return {@code true} if this line segment and the specified line
     *                  segment intersect each other;
     *                  {@code false} otherwise.
     * @since 1.2
     */
    public boolean intersectsLine(Line2D l) {
        return linesIntersect(l.getX1(), l.getY1(), l.getX2(), l.getY2(),
                              getX1(), getY1(), getX2(), getY2());
    }

    
Returns the square of the distance from a point to a line segment.
The distance measured is the distance between the specified
point and the closest point between the specified end points.
If the specified point intersects the line segment in between the
end points, this method returns 0.0.

Params:
  • x1 – the X coordinate of the start point of the
          specified line segment
  • y1 – the Y coordinate of the start point of the
          specified line segment
  • x2 – the X coordinate of the end point of the
          specified line segment
  • y2 – the Y coordinate of the end point of the
          specified line segment
  • px – the X coordinate of the specified point being
          measured against the specified line segment
  • py – the Y coordinate of the specified point being
          measured against the specified line segment
See Also:
Returns:a double value that is the square of the distance from the
                 specified point to the specified line segment.
Since:1.2
/**
     * Returns the square of the distance from a point to a line segment.
     * The distance measured is the distance between the specified
     * point and the closest point between the specified end points.
     * If the specified point intersects the line segment in between the
     * end points, this method returns 0.0.
     *
     * @param x1 the X coordinate of the start point of the
     *           specified line segment
     * @param y1 the Y coordinate of the start point of the
     *           specified line segment
     * @param x2 the X coordinate of the end point of the
     *           specified line segment
     * @param y2 the Y coordinate of the end point of the
     *           specified line segment
     * @param px the X coordinate of the specified point being
     *           measured against the specified line segment
     * @param py the Y coordinate of the specified point being
     *           measured against the specified line segment
     * @return a double value that is the square of the distance from the
     *                  specified point to the specified line segment.
     * @see #ptLineDistSq(double, double, double, double, double, double)
     * @since 1.2
     */
    public static double ptSegDistSq(double x1, double y1,
                                     double x2, double y2,
                                     double px, double py)
    {
        // Adjust vectors relative to x1,y1
        // x2,y2 becomes relative vector from x1,y1 to end of segment
        x2 -= x1;
        y2 -= y1;
        // px,py becomes relative vector from x1,y1 to test point
        px -= x1;
        py -= y1;
        double dotprod = px * x2 + py * y2;
        double projlenSq;
        if (dotprod <= 0.0) {
            // px,py is on the side of x1,y1 away from x2,y2
            // distance to segment is length of px,py vector
            // "length of its (clipped) projection" is now 0.0
            projlenSq = 0.0;
        } else {
            // switch to backwards vectors relative to x2,y2
            // x2,y2 are already the negative of x1,y1=>x2,y2
            // to get px,py to be the negative of px,py=>x2,y2
            // the dot product of two negated vectors is the same
            // as the dot product of the two normal vectors
            px = x2 - px;
            py = y2 - py;
            dotprod = px * x2 + py * y2;
            if (dotprod <= 0.0) {
                // px,py is on the side of x2,y2 away from x1,y1
                // distance to segment is length of (backwards) px,py vector
                // "length of its (clipped) projection" is now 0.0
                projlenSq = 0.0;
            } else {
                // px,py is between x1,y1 and x2,y2
                // dotprod is the length of the px,py vector
                // projected on the x2,y2=>x1,y1 vector times the
                // length of the x2,y2=>x1,y1 vector
                projlenSq = dotprod * dotprod / (x2 * x2 + y2 * y2);
            }
        }
        // Distance to line is now the length of the relative point
        // vector minus the length of its projection onto the line
        // (which is zero if the projection falls outside the range
        //  of the line segment).
        double lenSq = px * px + py * py - projlenSq;
        if (lenSq < 0) {
            lenSq = 0;
        }
        return lenSq;
    }

    
Returns the distance from a point to a line segment.
The distance measured is the distance between the specified
point and the closest point between the specified end points.
If the specified point intersects the line segment in between the
end points, this method returns 0.0.

Params:
  • x1 – the X coordinate of the start point of the
          specified line segment
  • y1 – the Y coordinate of the start point of the
          specified line segment
  • x2 – the X coordinate of the end point of the
          specified line segment
  • y2 – the Y coordinate of the end point of the
          specified line segment
  • px – the X coordinate of the specified point being
          measured against the specified line segment
  • py – the Y coordinate of the specified point being
          measured against the specified line segment
See Also:
Returns:a double value that is the distance from the specified point
                         to the specified line segment.
Since:1.2
/**
     * Returns the distance from a point to a line segment.
     * The distance measured is the distance between the specified
     * point and the closest point between the specified end points.
     * If the specified point intersects the line segment in between the
     * end points, this method returns 0.0.
     *
     * @param x1 the X coordinate of the start point of the
     *           specified line segment
     * @param y1 the Y coordinate of the start point of the
     *           specified line segment
     * @param x2 the X coordinate of the end point of the
     *           specified line segment
     * @param y2 the Y coordinate of the end point of the
     *           specified line segment
     * @param px the X coordinate of the specified point being
     *           measured against the specified line segment
     * @param py the Y coordinate of the specified point being
     *           measured against the specified line segment
     * @return a double value that is the distance from the specified point
     *                          to the specified line segment.
     * @see #ptLineDist(double, double, double, double, double, double)
     * @since 1.2
     */
    public static double ptSegDist(double x1, double y1,
                                   double x2, double y2,
                                   double px, double py)
    {
        return Math.sqrt(ptSegDistSq(x1, y1, x2, y2, px, py));
    }

    
Returns the square of the distance from a point to this line segment.
The distance measured is the distance between the specified
point and the closest point between the current line's end points.
If the specified point intersects the line segment in between the
end points, this method returns 0.0.

Params:
  • px – the X coordinate of the specified point being
          measured against this line segment
  • py – the Y coordinate of the specified point being
          measured against this line segment
See Also:
Returns:a double value that is the square of the distance from the
                 specified point to the current line segment.
Since:1.2
/**
     * Returns the square of the distance from a point to this line segment.
     * The distance measured is the distance between the specified
     * point and the closest point between the current line's end points.
     * If the specified point intersects the line segment in between the
     * end points, this method returns 0.0.
     *
     * @param px the X coordinate of the specified point being
     *           measured against this line segment
     * @param py the Y coordinate of the specified point being
     *           measured against this line segment
     * @return a double value that is the square of the distance from the
     *                  specified point to the current line segment.
     * @see #ptLineDistSq(double, double)
     * @since 1.2
     */
    public double ptSegDistSq(double px, double py) {
        return ptSegDistSq(getX1(), getY1(), getX2(), getY2(), px, py);
    }

    
Returns the square of the distance from a Point2D to this line segment. The distance measured is the distance between the specified point and the closest point between the current line's end points. If the specified point intersects the line segment in between the end points, this method returns 0.0. 
Params:
  • pt – the specified Point2D being measured against this line segment.
See Also:
Returns:a double value that is the square of the distance from the specified Point2D to the current line segment.
Since:1.2
/**
     * Returns the square of the distance from a {@code Point2D} to
     * this line segment.
     * The distance measured is the distance between the specified
     * point and the closest point between the current line's end points.
     * If the specified point intersects the line segment in between the
     * end points, this method returns 0.0.
     * @param pt the specified {@code Point2D} being measured against
     *           this line segment.
     * @return a double value that is the square of the distance from the
     *                  specified {@code Point2D} to the current
     *                  line segment.
     * @see #ptLineDistSq(Point2D)
     * @since 1.2
     */
    public double ptSegDistSq(Point2D pt) {
        return ptSegDistSq(getX1(), getY1(), getX2(), getY2(),
                           pt.getX(), pt.getY());
    }

    
Returns the distance from a point to this line segment.
The distance measured is the distance between the specified
point and the closest point between the current line's end points.
If the specified point intersects the line segment in between the
end points, this method returns 0.0.

Params:
  • px – the X coordinate of the specified point being
          measured against this line segment
  • py – the Y coordinate of the specified point being
          measured against this line segment
See Also:
Returns:a double value that is the distance from the specified
                 point to the current line segment.
Since:1.2
/**
     * Returns the distance from a point to this line segment.
     * The distance measured is the distance between the specified
     * point and the closest point between the current line's end points.
     * If the specified point intersects the line segment in between the
     * end points, this method returns 0.0.
     *
     * @param px the X coordinate of the specified point being
     *           measured against this line segment
     * @param py the Y coordinate of the specified point being
     *           measured against this line segment
     * @return a double value that is the distance from the specified
     *                  point to the current line segment.
     * @see #ptLineDist(double, double)
     * @since 1.2
     */
    public double ptSegDist(double px, double py) {
        return ptSegDist(getX1(), getY1(), getX2(), getY2(), px, py);
    }

    
Returns the distance from a Point2D to this line segment. The distance measured is the distance between the specified point and the closest point between the current line's end points. If the specified point intersects the line segment in between the end points, this method returns 0.0. 
Params:
  • pt – the specified Point2D being measured against this line segment
See Also:
Returns:a double value that is the distance from the specified Point2D to the current line segment.
Since:1.2
/**
     * Returns the distance from a {@code Point2D} to this line
     * segment.
     * The distance measured is the distance between the specified
     * point and the closest point between the current line's end points.
     * If the specified point intersects the line segment in between the
     * end points, this method returns 0.0.
     * @param pt the specified {@code Point2D} being measured
     *          against this line segment
     * @return a double value that is the distance from the specified
     *                          {@code Point2D} to the current line
     *                          segment.
     * @see #ptLineDist(Point2D)
     * @since 1.2
     */
    public double ptSegDist(Point2D pt) {
        return ptSegDist(getX1(), getY1(), getX2(), getY2(),
                         pt.getX(), pt.getY());
    }

    
Returns the square of the distance from a point to a line.
The distance measured is the distance between the specified
point and the closest point on the infinitely-extended line
defined by the specified coordinates.  If the specified point
intersects the line, this method returns 0.0.

Params:
  • x1 – the X coordinate of the start point of the specified line
  • y1 – the Y coordinate of the start point of the specified line
  • x2 – the X coordinate of the end point of the specified line
  • y2 – the Y coordinate of the end point of the specified line
  • px – the X coordinate of the specified point being
          measured against the specified line
  • py – the Y coordinate of the specified point being
          measured against the specified line
See Also:
Returns:a double value that is the square of the distance from the
                 specified point to the specified line.
Since:1.2
/**
     * Returns the square of the distance from a point to a line.
     * The distance measured is the distance between the specified
     * point and the closest point on the infinitely-extended line
     * defined by the specified coordinates.  If the specified point
     * intersects the line, this method returns 0.0.
     *
     * @param x1 the X coordinate of the start point of the specified line
     * @param y1 the Y coordinate of the start point of the specified line
     * @param x2 the X coordinate of the end point of the specified line
     * @param y2 the Y coordinate of the end point of the specified line
     * @param px the X coordinate of the specified point being
     *           measured against the specified line
     * @param py the Y coordinate of the specified point being
     *           measured against the specified line
     * @return a double value that is the square of the distance from the
     *                  specified point to the specified line.
     * @see #ptSegDistSq(double, double, double, double, double, double)
     * @since 1.2
     */
    public static double ptLineDistSq(double x1, double y1,
                                      double x2, double y2,
                                      double px, double py)
    {
        // Adjust vectors relative to x1,y1
        // x2,y2 becomes relative vector from x1,y1 to end of segment
        x2 -= x1;
        y2 -= y1;
        // px,py becomes relative vector from x1,y1 to test point
        px -= x1;
        py -= y1;
        double dotprod = px * x2 + py * y2;
        // dotprod is the length of the px,py vector
        // projected on the x1,y1=>x2,y2 vector times the
        // length of the x1,y1=>x2,y2 vector
        double projlenSq = dotprod * dotprod / (x2 * x2 + y2 * y2);
        // Distance to line is now the length of the relative point
        // vector minus the length of its projection onto the line
        double lenSq = px * px + py * py - projlenSq;
        if (lenSq < 0) {
            lenSq = 0;
        }
        return lenSq;
    }

    
Returns the distance from a point to a line.
The distance measured is the distance between the specified
point and the closest point on the infinitely-extended line
defined by the specified coordinates.  If the specified point
intersects the line, this method returns 0.0.

Params:
  • x1 – the X coordinate of the start point of the specified line
  • y1 – the Y coordinate of the start point of the specified line
  • x2 – the X coordinate of the end point of the specified line
  • y2 – the Y coordinate of the end point of the specified line
  • px – the X coordinate of the specified point being
          measured against the specified line
  • py – the Y coordinate of the specified point being
          measured against the specified line
See Also:
Returns:a double value that is the distance from the specified
                  point to the specified line.
Since:1.2
/**
     * Returns the distance from a point to a line.
     * The distance measured is the distance between the specified
     * point and the closest point on the infinitely-extended line
     * defined by the specified coordinates.  If the specified point
     * intersects the line, this method returns 0.0.
     *
     * @param x1 the X coordinate of the start point of the specified line
     * @param y1 the Y coordinate of the start point of the specified line
     * @param x2 the X coordinate of the end point of the specified line
     * @param y2 the Y coordinate of the end point of the specified line
     * @param px the X coordinate of the specified point being
     *           measured against the specified line
     * @param py the Y coordinate of the specified point being
     *           measured against the specified line
     * @return a double value that is the distance from the specified
     *                   point to the specified line.
     * @see #ptSegDist(double, double, double, double, double, double)
     * @since 1.2
     */
    public static double ptLineDist(double x1, double y1,
                                    double x2, double y2,
                                    double px, double py)
    {
        return Math.sqrt(ptLineDistSq(x1, y1, x2, y2, px, py));
    }

    
Returns the square of the distance from a point to this line. The distance measured is the distance between the specified point and the closest point on the infinitely-extended line defined by this Line2D. If the specified point intersects the line, this method returns 0.0. 
Params:
  • px – the X coordinate of the specified point being
          measured against this line
  • py – the Y coordinate of the specified point being
          measured against this line
See Also:
Returns:a double value that is the square of the distance from a
                 specified point to the current line.
Since:1.2
/**
     * Returns the square of the distance from a point to this line.
     * The distance measured is the distance between the specified
     * point and the closest point on the infinitely-extended line
     * defined by this {@code Line2D}.  If the specified point
     * intersects the line, this method returns 0.0.
     *
     * @param px the X coordinate of the specified point being
     *           measured against this line
     * @param py the Y coordinate of the specified point being
     *           measured against this line
     * @return a double value that is the square of the distance from a
     *                  specified point to the current line.
     * @see #ptSegDistSq(double, double)
     * @since 1.2
     */
    public double ptLineDistSq(double px, double py) {
        return ptLineDistSq(getX1(), getY1(), getX2(), getY2(), px, py);
    }

    
Returns the square of the distance from a specified Point2D to this line. The distance measured is the distance between the specified point and the closest point on the infinitely-extended line defined by this Line2D. If the specified point intersects the line, this method returns 0.0. 
Params:
  • pt – the specified Point2D being measured against this line
See Also:
Returns:a double value that is the square of the distance from a specified Point2D to the current line.
Since:1.2
/**
     * Returns the square of the distance from a specified
     * {@code Point2D} to this line.
     * The distance measured is the distance between the specified
     * point and the closest point on the infinitely-extended line
     * defined by this {@code Line2D}.  If the specified point
     * intersects the line, this method returns 0.0.
     * @param pt the specified {@code Point2D} being measured
     *           against this line
     * @return a double value that is the square of the distance from a
     *                  specified {@code Point2D} to the current
     *                  line.
     * @see #ptSegDistSq(Point2D)
     * @since 1.2
     */
    public double ptLineDistSq(Point2D pt) {
        return ptLineDistSq(getX1(), getY1(), getX2(), getY2(),
                            pt.getX(), pt.getY());
    }

    
Returns the distance from a point to this line. The distance measured is the distance between the specified point and the closest point on the infinitely-extended line defined by this Line2D. If the specified point intersects the line, this method returns 0.0. 
Params:
  • px – the X coordinate of the specified point being
          measured against this line
  • py – the Y coordinate of the specified point being
          measured against this line
See Also:
Returns:a double value that is the distance from a specified point
                 to the current line.
Since:1.2
/**
     * Returns the distance from a point to this line.
     * The distance measured is the distance between the specified
     * point and the closest point on the infinitely-extended line
     * defined by this {@code Line2D}.  If the specified point
     * intersects the line, this method returns 0.0.
     *
     * @param px the X coordinate of the specified point being
     *           measured against this line
     * @param py the Y coordinate of the specified point being
     *           measured against this line
     * @return a double value that is the distance from a specified point
     *                  to the current line.
     * @see #ptSegDist(double, double)
     * @since 1.2
     */
    public double ptLineDist(double px, double py) {
        return ptLineDist(getX1(), getY1(), getX2(), getY2(), px, py);
    }

    
Returns the distance from a Point2D to this line. The distance measured is the distance between the specified point and the closest point on the infinitely-extended line defined by this Line2D. If the specified point intersects the line, this method returns 0.0. 
Params:
  • pt – the specified Point2D being measured
See Also:
Returns:a double value that is the distance from a specified Point2D to the current line.
Since:1.2
/**
     * Returns the distance from a {@code Point2D} to this line.
     * The distance measured is the distance between the specified
     * point and the closest point on the infinitely-extended line
     * defined by this {@code Line2D}.  If the specified point
     * intersects the line, this method returns 0.0.
     * @param pt the specified {@code Point2D} being measured
     * @return a double value that is the distance from a specified
     *                  {@code Point2D} to the current line.
     * @see #ptSegDist(Point2D)
     * @since 1.2
     */
    public double ptLineDist(Point2D pt) {
        return ptLineDist(getX1(), getY1(), getX2(), getY2(),
                         pt.getX(), pt.getY());
    }

    
Tests if a specified coordinate is inside the boundary of this Line2D. This method is required to implement the Shape interface, but in the case of Line2D objects it always returns false since a line contains no area. 
Params:
  • x – the X coordinate of the specified point to be tested
  • y – the Y coordinate of the specified point to be tested
Returns:false because a Line2D contains no area.
Since:1.2
/**
     * Tests if a specified coordinate is inside the boundary of this
     * {@code Line2D}.  This method is required to implement the
     * {@link Shape} interface, but in the case of {@code Line2D}
     * objects it always returns {@code false} since a line contains
     * no area.
     * @param x the X coordinate of the specified point to be tested
     * @param y the Y coordinate of the specified point to be tested
     * @return {@code false} because a {@code Line2D} contains
     * no area.
     * @since 1.2
     */
    public boolean contains(double x, double y) {
        return false;
    }

    
Tests if a given Point2D is inside the boundary of this Line2D. This method is required to implement the Shape interface, but in the case of Line2D objects it always returns false since a line contains no area. 
Params:
  • p – the specified Point2D to be tested
Returns:false because a Line2D contains no area.
Since:1.2
/**
     * Tests if a given {@code Point2D} is inside the boundary of
     * this {@code Line2D}.
     * This method is required to implement the {@link Shape} interface,
     * but in the case of {@code Line2D} objects it always returns
     * {@code false} since a line contains no area.
     * @param p the specified {@code Point2D} to be tested
     * @return {@code false} because a {@code Line2D} contains
     * no area.
     * @since 1.2
     */
    public boolean contains(Point2D p) {
        return false;
    }

    
{@inheritDoc}

Since:1.2
/**
     * {@inheritDoc}
     * @since 1.2
     */
    public boolean intersects(double x, double y, double w, double h) {
        return intersects(new Rectangle2D.Double(x, y, w, h));
    }

    
{@inheritDoc}

Since:1.2
/**
     * {@inheritDoc}
     * @since 1.2
     */
    public boolean intersects(Rectangle2D r) {
        return r.intersectsLine(getX1(), getY1(), getX2(), getY2());
    }

    
Tests if the interior of this Line2D entirely contains the specified set of rectangular coordinates. This method is required to implement the Shape interface, but in the case of Line2D objects it always returns false since a line contains no area. 
Params:
  • x – the X coordinate of the upper-left corner of the
         specified rectangular area
  • y – the Y coordinate of the upper-left corner of the
         specified rectangular area
  • w – the width of the specified rectangular area
  • h – the height of the specified rectangular area
Returns:false because a Line2D contains no area.
Since:1.2
/**
     * Tests if the interior of this {@code Line2D} entirely contains
     * the specified set of rectangular coordinates.
     * This method is required to implement the {@code Shape} interface,
     * but in the case of {@code Line2D} objects it always returns
     * false since a line contains no area.
     * @param x the X coordinate of the upper-left corner of the
     *          specified rectangular area
     * @param y the Y coordinate of the upper-left corner of the
     *          specified rectangular area
     * @param w the width of the specified rectangular area
     * @param h the height of the specified rectangular area
     * @return {@code false} because a {@code Line2D} contains
     * no area.
     * @since 1.2
     */
    public boolean contains(double x, double y, double w, double h) {
        return false;
    }

    
Tests if the interior of this Line2D entirely contains the specified Rectangle2D. This method is required to implement the Shape interface, but in the case of Line2D objects it always returns false since a line contains no area. 
Params:
  • r – the specified Rectangle2D to be tested
Returns:false because a Line2D contains no area.
Since:1.2
/**
     * Tests if the interior of this {@code Line2D} entirely contains
     * the specified {@code Rectangle2D}.
     * This method is required to implement the {@code Shape} interface,
     * but in the case of {@code Line2D} objects it always returns
     * {@code false} since a line contains no area.
     * @param r the specified {@code Rectangle2D} to be tested
     * @return {@code false} because a {@code Line2D} contains
     * no area.
     * @since 1.2
     */
    public boolean contains(Rectangle2D r) {
        return false;
    }

    
{@inheritDoc}

Since:1.2
/**
     * {@inheritDoc}
     * @since 1.2
     */
    public Rectangle getBounds() {
        return getBounds2D().getBounds();
    }

    
Returns an iteration object that defines the boundary of this Line2D. The iterator for this class is not multi-threaded safe, which means that this Line2D class does not guarantee that modifications to the geometry of this Line2D object do not affect any iterations of that geometry that are already in process. 
Params:
Returns:a PathIterator that defines the boundary of this Line2D.
Since:1.2
/**
     * Returns an iteration object that defines the boundary of this
     * {@code Line2D}.
     * The iterator for this class is not multi-threaded safe,
     * which means that this {@code Line2D} class does not
     * guarantee that modifications to the geometry of this
     * {@code Line2D} object do not affect any iterations of that
     * geometry that are already in process.
     * @param at the specified {@link AffineTransform}
     * @return a {@link PathIterator} that defines the boundary of this
     *          {@code Line2D}.
     * @since 1.2
     */
    public PathIterator getPathIterator(AffineTransform at) {
        return new LineIterator(this, at);
    }

    
Returns an iteration object that defines the boundary of this flattened Line2D. The iterator for this class is not multi-threaded safe, which means that this Line2D class does not guarantee that modifications to the geometry of this Line2D object do not affect any iterations of that geometry that are already in process. 
Params:
  • at – the specified AffineTransform
  • flatness – the maximum amount that the control points for a given curve can vary from colinear before a subdivided curve is replaced by a straight line connecting the end points. Since a Line2D object is always flat, this parameter is ignored.
Returns:a PathIterator that defines the boundary of the flattened Line2D
Since:1.2
/**
     * Returns an iteration object that defines the boundary of this
     * flattened {@code Line2D}.
     * The iterator for this class is not multi-threaded safe,
     * which means that this {@code Line2D} class does not
     * guarantee that modifications to the geometry of this
     * {@code Line2D} object do not affect any iterations of that
     * geometry that are already in process.
     * @param at the specified {@code AffineTransform}
     * @param flatness the maximum amount that the control points for a
     *          given curve can vary from colinear before a subdivided
     *          curve is replaced by a straight line connecting the
     *          end points.  Since a {@code Line2D} object is
     *          always flat, this parameter is ignored.
     * @return a {@code PathIterator} that defines the boundary of the
     *                  flattened {@code Line2D}
     * @since 1.2
     */
    public PathIterator getPathIterator(AffineTransform at, double flatness) {
        return new LineIterator(this, at);
    }

    
Creates a new object of the same class as this object.

Throws:
See Also:
Returns:    a clone of this instance.
Since:     1.2
/**
     * Creates a new object of the same class as this object.
     *
     * @return     a clone of this instance.
     * @exception  OutOfMemoryError            if there is not enough memory.
     * @see        java.lang.Cloneable
     * @since      1.2
     */
    public Object clone() {
        try {
            return super.clone();
        } catch (CloneNotSupportedException e) {
            // this shouldn't happen, since we are Cloneable
            throw new InternalError(e);
        }
    }
}