Java 将graphics.Images转换为org.zkoss.image.image

我正在做一个zk项目，我想在web界面上显示一些图像。我面临的问题是，模型中的contentProvider给了我swt.graphics.Image，而我没有找到显示它们的方法。

在zk 8中，图像以java.awt.Image.renderImage作为setter 在谷歌搜索时，您会进入以下网站：

因为链接将来可能会死掉，所以我将代码复制/粘贴到这里，但请注意，我不是代码的作者

/*******************************************************************************
 * Copyright (c) 2000, 2016 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.swt.snippets;

/*
 * example snippet: convert between SWT Image and AWT BufferedImage
 *
 * For a list of all SWT example snippets see
 * http://www.eclipse.org/swt/snippets/
 */
import java.awt.*;
import java.awt.image.*;

import org.eclipse.swt.*;
import org.eclipse.swt.graphics.*;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.graphics.Rectangle;
import org.eclipse.swt.widgets.*;

public class Snippet156 {

static BufferedImage convertToAWT(ImageData data) {
    ColorModel colorModel = null;
    PaletteData palette = data.palette;
    if (palette.isDirect) {
        colorModel = new DirectColorModel(data.depth, palette.redMask, palette.greenMask, palette.blueMask);
        BufferedImage bufferedImage = new BufferedImage(colorModel, colorModel.createCompatibleWritableRaster(data.width, data.height), false, null);
        for (int y = 0; y < data.height; y++) {
            for (int x = 0; x < data.width; x++) {
                int pixel = data.getPixel(x, y);
                RGB rgb = palette.getRGB(pixel);
                bufferedImage.setRGB(x, y,  rgb.red << 16 | rgb.green << 8 | rgb.blue);
            }
        }
        return bufferedImage;
    } else {
        RGB[] rgbs = palette.getRGBs();
        byte[] red = new byte[rgbs.length];
        byte[] green = new byte[rgbs.length];
        byte[] blue = new byte[rgbs.length];
        for (int i = 0; i < rgbs.length; i++) {
            RGB rgb = rgbs[i];
            red[i] = (byte)rgb.red;
            green[i] = (byte)rgb.green;
            blue[i] = (byte)rgb.blue;
        }
        if (data.transparentPixel != -1) {
            colorModel = new IndexColorModel(data.depth, rgbs.length, red, green, blue, data.transparentPixel);
        } else {
            colorModel = new IndexColorModel(data.depth, rgbs.length, red, green, blue);
        }
        BufferedImage bufferedImage = new BufferedImage(colorModel, colorModel.createCompatibleWritableRaster(data.width, data.height), false, null);
        WritableRaster raster = bufferedImage.getRaster();
        int[] pixelArray = new int[1];
        for (int y = 0; y < data.height; y++) {
            for (int x = 0; x < data.width; x++) {
                int pixel = data.getPixel(x, y);
                pixelArray[0] = pixel;
                raster.setPixel(x, y, pixelArray);
            }
        }
        return bufferedImage;
    }
}

static ImageData convertToSWT(BufferedImage bufferedImage) {
    if (bufferedImage.getColorModel() instanceof DirectColorModel) {
        DirectColorModel colorModel = (DirectColorModel)bufferedImage.getColorModel();
        PaletteData palette = new PaletteData(colorModel.getRedMask(), colorModel.getGreenMask(), colorModel.getBlueMask());
        ImageData data = new ImageData(bufferedImage.getWidth(), bufferedImage.getHeight(), colorModel.getPixelSize(), palette);
        for (int y = 0; y < data.height; y++) {
            for (int x = 0; x < data.width; x++) {
                int rgb = bufferedImage.getRGB(x, y);
                int pixel = palette.getPixel(new RGB((rgb >> 16) & 0xFF, (rgb >> 8) & 0xFF, rgb & 0xFF));
                data.setPixel(x, y, pixel);
                if (colorModel.hasAlpha()) {
                    data.setAlpha(x, y, (rgb >> 24) & 0xFF);
                }
            }
        }
        return data;
    } else if (bufferedImage.getColorModel() instanceof IndexColorModel) {
        IndexColorModel colorModel = (IndexColorModel)bufferedImage.getColorModel();
        int size = colorModel.getMapSize();
        byte[] reds = new byte[size];
        byte[] greens = new byte[size];
        byte[] blues = new byte[size];
        colorModel.getReds(reds);
        colorModel.getGreens(greens);
        colorModel.getBlues(blues);
        RGB[] rgbs = new RGB[size];
        for (int i = 0; i < rgbs.length; i++) {
            rgbs[i] = new RGB(reds[i] & 0xFF, greens[i] & 0xFF, blues[i] & 0xFF);
        }
        PaletteData palette = new PaletteData(rgbs);
        ImageData data = new ImageData(bufferedImage.getWidth(), bufferedImage.getHeight(), colorModel.getPixelSize(), palette);
        data.transparentPixel = colorModel.getTransparentPixel();
        WritableRaster raster = bufferedImage.getRaster();
        int[] pixelArray = new int[1];
        for (int y = 0; y < data.height; y++) {
            for (int x = 0; x < data.width; x++) {
                raster.getPixel(x, y, pixelArray);
                data.setPixel(x, y, pixelArray[0]);
            }
        }
        return data;
    }
    return null;
}

static ImageData createSampleImage(Display display) {
    Image image = new Image(display, 100, 100);
    Rectangle bounds = image.getBounds();
    GC gc = new GC(image);
    gc.setBackground(display.getSystemColor(SWT.COLOR_BLUE));
    gc.fillRectangle(bounds);
    gc.setBackground(display.getSystemColor(SWT.COLOR_GREEN));
    gc.fillOval(0, 0, bounds.width, bounds.height);
    gc.setForeground(display.getSystemColor(SWT.COLOR_RED));
    gc.drawLine(0, 0, bounds.width, bounds.height);
    gc.drawLine(bounds.width, 0, 0, bounds.height);
    gc.dispose();
    ImageData data = image.getImageData();
    image.dispose();
    return data;
}

public static void main(String[] args) {
    Display display = new Display();
    Shell shell = new Shell(display);
    shell.setText("SWT Image");
    ImageData data;
    if (args.length > 0) {
        String fileName = args[0];
        data = new ImageData(fileName);
    } else {
        data = createSampleImage(display);
    }
    final Image swtImage = new Image(display, data);
    final BufferedImage awtImage = convertToAWT(data);
    final Image swtImage2 = new Image(display, convertToSWT(awtImage));
    shell.addListener(SWT.Paint, e -> {
        int y = 10;
        if (swtImage != null) {
            e.gc.drawImage(swtImage, 10, y);
            y += swtImage.getBounds().height + 10;
        }
        if (swtImage2 != null) {
            e.gc.drawImage(swtImage2, 10, y);
        }
    });
    Frame frame = new Frame() {
        @Override
        public void paint(Graphics g) {
            Insets insets = getInsets();
            if (awtImage != null) {
                g.drawImage(awtImage, 10 + insets.left, 10 + insets.top, null);
            }
        }
    };
    frame.setTitle("AWT Image");
    shell.setLocation(50, 50);
    Rectangle bounds = swtImage.getBounds();
    shell.setSize(bounds.width + 50, bounds.height * 2 + 100);
    Point size = shell.getSize();
    Point location = shell.getLocation();
    Insets insets = frame.getInsets();
    frame.setLocation(location.x + size.x + 10, location.y);
    frame.setSize(size.x - (insets.left + insets.right), size.y - (insets.top + insets.bottom));
    frame.setVisible(true);
    shell.open();
    while (!shell.isDisposed()) {
        if (!display.readAndDispatch()) display.sleep();
    }
    if (swtImage != null) swtImage.dispose();
    if (swtImage2 != null) swtImage.dispose();
    frame.dispose();
    display.dispose();
    /* Note: If you are using JDK 1.3.x, you need to use System.exit(0) at the end of your program to exit AWT.
     * This is because in 1.3.x, AWT does not exit when the frame is disposed, because the AWT thread is not a daemon.
     * This was fixed in JDK 1.4.x with the addition of the AWT Shutdown thread.
     */
}
}

---

ImageLoader.save应该能够将任何swt.graphics.Image写入输出流。您可以简单地基于此创建一个servlet，以便将图像返回到浏览器。它工作正常，但问题是，当我使用convertToAWTImageData时，我得到的是黑色背景，而不是透明背景

public class ImageToZkImageCoverter implements Converter<AImage, byte[], Image> {

    private Log logger = LogFactory.getLog(ImageToZkImageCoverter.class);

    @Override
    public byte[] coerceToBean(AImage compAttr, Image component, BindContext ctx) {
        logger.debug("Converting the image");
        return compAttr.getByteData();
    }

    @Override
    public AImage coerceToUi(byte[] beanProp, Image component, BindContext ctx) {
        try {
            if (beanProp != null && beanProp.length > 0) {
                AImage im = new AImage("", beanProp);
                component.setContent(im);
                logger.trace("Return an image, length = " + beanProp.length);
                return im;
            }
            logger.debug("Return null => image is empty");
            return null;
        } catch (IOException e) {
            logger.error("Error occured, returning null", e);
            return null;
        }
    }
}