java web中读取windows对应文件名的 系统图标 。。。。显示
1.获取系统图标工具类
package utils;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GraphicsConfiguration;
import java.awt.GraphicsDevice;
import java.awt.GraphicsEnvironment;
import java.awt.HeadlessException;
import java.awt.Image;
import java.awt.Transparency;
import java.awt.image.BufferedImage;
import java.awt.image.ColorModel;
import java.awt.image.PixelGrabber;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import javax.swing.Icon;
import javax.swing.ImageIcon;
import sun.awt.shell.ShellFolder;
public class CommonTool {
public static BufferedImage getImageByFileTyle(String filename)
throws FileNotFoundException {
File file = null;
String extension = filename.substring(filename.lastIndexOf("."))
.toLowerCase();
try {
file = File.createTempFile("icon", extension);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return toBufferedImage(toImage(toIcon(file)));
}
public static Icon toIcon(File file) throws FileNotFoundException {
ShellFolder shellFolder = ShellFolder.getShellFolder(file);
Icon icon = new ImageIcon(shellFolder.getIcon(true));
return icon;
}
public static Image toImage(Icon icon) {
if (icon instanceof ImageIcon) {
return ((ImageIcon) icon).getImage();
} else {
int w = icon.getIconWidth();
int h = icon.getIconHeight();
GraphicsEnvironment ge = GraphicsEnvironment
.getLocalGraphicsEnvironment();
GraphicsDevice gd = ge.getDefaultScreenDevice();
GraphicsConfiguration gc = gd.getDefaultConfiguration();
BufferedImage image = gc.createCompatibleImage(w, h);
Graphics2D g = image.createGraphics();
icon.paintIcon(null, g, 0, 0);
g.dispose();
return image;
}
}
private static boolean hasAlpha(Image image) {
// If buffered image, the color model is readily available
if (image instanceof BufferedImage) {
BufferedImage bimage = (BufferedImage) image;
return bimage.getColorModel().hasAlpha();
}
// Use a pixel grabber to retrieve the image's color model;
// grabbing a single pixel is usually sufficient
PixelGrabber pg = new PixelGrabber(image, 0, 0, 1, 1, false);
try {
pg.grabPixels();
} catch (InterruptedException e) {
}
// Get the image's color model
ColorModel cm = pg.getColorModel();
return cm.hasAlpha();
}
// This method returns a buffered image with the contents of an image
public static BufferedImage toBufferedImage(Image image) {
if (image instanceof BufferedImage) {
return (BufferedImage) image;
}
// This code ensures that all the pixels in the image are loaded
image = new ImageIcon(image).getImage();
// Determine if the image has transparent pixels; for this method's
// implementation, see Determining If an Image Has Transparent Pixels
boolean hasAlpha = hasAlpha(image);
// Create a buffered image with a format that's compatible with the
// screen
BufferedImage bimage = null;
GraphicsEnvironment ge = GraphicsEnvironment
.getLocalGraphicsEnvironment();
try {
// Determine the type of transparency of the new buffered image
int transparency = Transparency.OPAQUE;
if (hasAlpha) {
transparency = Transparency.BITMASK;
}
// Create the buffered image
GraphicsDevice gs = ge.getDefaultScreenDevice();
GraphicsConfiguration gc = gs.getDefaultConfiguration();
bimage = gc.createCompatibleImage(image.getWidth(null), image
.getHeight(null), transparency);
} catch (HeadlessException e) {
// The system does not have a screen
}
if (bimage == null) {
// Create a buffered image using the default color model
int type = BufferedImage.TYPE_INT_RGB;
if (hasAlpha) {
type = BufferedImage.TYPE_INT_ARGB;
}
bimage = new BufferedImage(image.getWidth(null), image
.getHeight(null), type);
}
// Copy image to buffered image
Graphics g = bimage.createGraphics();
// Paint the image onto the buffered image
g.drawImage(image, 0, 0, null);
g.dispose();
return bimage;
}
}
2.调用
<img src="uploaddispalyIcon?dirName=<%=pathdir+"upload/"%>${name}" style="width:15px;height:15px;"/>
public void dispalyIcon() {
HttpServletResponse response = ServletActionContext.getResponse();
response.setContentType("image/png");
BufferedImage myImage=null;
OutputStream sos =null;
try {
sos = response.getOutputStream();
myImage = CommonTool.getImageByFileTyle(dirName);
ImageIO.write(myImage, "png", sos);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}finally{
if(null!=myImage&&null!=sos){
try {
myImage.flush();
sos.flush();
sos.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
}