sunjpegencoderadapter.java

来自「JfreeChart 常用图表例子」· Java 代码 · 共 143 行

/* ===========================================================
 * JFreeChart : a free chart library for the Java(tm) platform
 * ===========================================================
 *
 * (C) Copyright 2000-2005, 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
 *
 * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 
 * in the United States and other countries.]
 *
 * -------------------
 * SunJPEGEncoderAdapter.java
 * -------------------
 * (C) Copyright 2004, by Richard Atkinson and Contributors.
 *
 * Original Author:  Richard Atkinson;
 * Contributor(s):   -;
 *
 * $Id: SunJPEGEncoderAdapter.java,v 1.3 2005/03/28 19:38:57 mungady Exp $
 *
 * Changes
 * -------
 * 01-Aug-2004 : Initial version (RA);
 *
 */

package org.jfree.chart.encoders;

import com.sun.image.codec.jpeg.JPEGImageEncoder;
import com.sun.image.codec.jpeg.JPEGCodec;
import com.sun.image.codec.jpeg.JPEGEncodeParam;

import java.awt.image.BufferedImage;
import java.io.IOException;
import java.io.OutputStream;
import java.io.ByteArrayOutputStream;

/**
 * Adapter class for the Sun JPEG Encoder.
 *
 * @author Richard Atkinson
 */
public class SunJPEGEncoderAdapter implements ImageEncoder {
    private float quality = 0.75f;

    /**
     * Default constructor.
     */
    public SunJPEGEncoderAdapter() {
    }

    /**
     * Get the quality of the image encoding.
     *
     * @return A float representing the quality.
     */
    public float getQuality() {
        return this.quality;
    }

    /**
     * Set the quality of the image encoding (supported).
     *
     * @param quality  A float representing the quality.
     */
    public void setQuality(float quality) {
        this.quality = quality;
    }

    /**
     * Get whether the encoder encodes alpha transparency (always false).
     *
     * @return Whether the encoder is encoding alpha transparency.
     */
    public boolean isEncodingAlpha() {
        return false;
    }

    /**
     * Set whether the encoder should encode alpha transparency (not supported 
     * for JPEG).
     *
     * @param encodingAlpha  Whether the encoder should encode alpha 
     *                       transparency.
     */
    public void setEncodingAlpha(boolean encodingAlpha) {
        //  No op
    }

    /**
     * Encodes an image in JPEG format.
     *
     * @param bufferedImage  The image to be encoded.
     * 
     * @return The byte[] that is the encoded image.
     * 
     * @throws IOException
     */
    public byte[] encode(BufferedImage bufferedImage) throws IOException {
        ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
        encode(bufferedImage, outputStream);
        return outputStream.toByteArray();
    }

    /**
     * Encodes an image in JPEG format and writes it to an OutputStream.
     *
     * @param bufferedImage  The image to be encoded.
     * @param outputStream  The OutputStream to write the encoded image to.
     * @throws IOException
     */
    public void encode(BufferedImage bufferedImage, OutputStream outputStream) 
        throws IOException {
        if (bufferedImage == null) {
            throw new IllegalArgumentException("Null 'image' argument.");
        }
        if (outputStream == null) {
            throw new IllegalArgumentException("Null 'outputStream' argument.");
        }
        JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(outputStream);
        JPEGEncodeParam param 
            = encoder.getDefaultJPEGEncodeParam(bufferedImage);
        param.setQuality(this.quality, true);
        encoder.encode(bufferedImage, param);
    }

}