swt通过扩展名取系统图标，swt扩展名取图标,eclipse swt可

swt通过扩展名取系统图标，swt扩展名取图标,eclipse swt可

eclipse swt可以通过扩展名取得Program，从而取得系统图标，必须注意的是，在Linux平台下是扩展名是分大小写的，这里统一转化为小写处理即可。参考代码如下：

package cn.outofmemory.test.resource;import java.util.Enumeration;import java.util.Hashtable;import java.util.logging.Logger;import org.eclipse.jface.resource.ImageDescriptor;import org.eclipse.swt.SWT;import org.eclipse.swt.graphics.Image;import org.eclipse.swt.graphics.ImageData;import org.eclipse.swt.program.Program;/** * 图像工厂 *  * @author Leo *  */public class ImageFactory {    private static final Logger LOG = Logger.getLogger(ImageFactory.class.getName());    public static final String UNKNOWN_FILE = "unknown.png";    public static final String DLL_FILE = "dll.png";    private static Hashtable<String, Image> images = new Hashtable<String, Image>();    private ImageFactory() {    }       /**     * 销毁工厂     */    public static void dispose() {        Enumeration<Image> e = images.elements();        while (e.hasMoreElements()) {            Image image = e.nextElement();            if (!image.isDisposed()) {                image.dispose();            }        }        images.clear();    }    /**     * 取文件的系统图标     *      * @param fileName     *            文件名     * @return 文件的系统图标     */    public static Image getSystemIconImage(String fileName) {        if (fileName == null) {            SWT.error(SWT.ERROR_NULL_ARGUMENT);        }        Image iconImage = null;        int dot = fileName.lastIndexOf('.');        if (dot != -1) {// 有扩展名            String extension = fileName.substring(dot).toLowerCase();//linux下分大小 写            iconImage = images.get(extension);//缓存            if (iconImage == null) {                iconImage = loadProgramImage(extension);            }            if (iconImage == null) {// 无系统关联图标                LOG.info("无系统关联图标："+fileName);                iconImage = loadDefined(extension);            }        } else {// 无扩展名            iconImage = loadImage(UNKNOWN_FILE);        }        return iconImage;    }    /**     * 加载预定义图标     * @param extension 文件扩展名     * @return 预定义图标，或未知图标     */    private static Image loadDefined(String extension) {        Image iconImage;        if (".dll".equals(extension)) {            iconImage = loadImage(DLL_FILE);        } else {            iconImage = loadImage(UNKNOWN_FILE);        }        images.put(extension, iconImage);        return iconImage;    }    /**     * 加载关联图标     * @param extension 文件扩展名     * @return 文件的关联图标，或为 null     */    private static Image loadProgramImage(String extension) {        Image iconImage = null;        Program program = Program.findProgram(extension);        if (program != null) {            ImageData imageData = program.getImageData();            if (imageData != null) {                iconImage = new Image(null, imageData,                        imageData.getTransparencyMask());                images.put(extension, iconImage);            }        }        return iconImage;    }}