Question

java 中:write Image问题

求高手帮忙写一个方法的实现 ~！！
public void write( Image img,File file){
//将img图像写入到file这个文件中。。这个方法该怎么实现！！
// 如果用 ImageIO.write(...) ，但是它的参数为 BufferedImage...
}
谢谢！好东西~！
不知道 国外代码 在哪里能看~~？~~一般网站好像没见过

Answer 1

//你运气好，给一个工具类，代码是国外的。

import java.awt.Graphics;
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.IOException;

import javax.imageio.ImageIO;
import javax.swing.ImageIcon;

public class TestWrite {
public static boolean write(Image img, File file) {
BufferedImage image = toBufferedImage(img);
try {
ImageIO.write(image, "jpg", file);
} catch (IOException e) {
e.printStackTrace();
}
return file.exists();
}

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 e661 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;
}
GraphicsDevice gs = ge.getDefaultScreenDevice();
GraphicsConfiguration gc = gs.getDefaultConfiguration();
// Create the buffered image
bimage = gc.createCompatibleImage(image.getWidth(null), image
.getHeight(null), transparency);
} catch (HeadlessException e) {
// The system does not have a screen
e.printStackTrace();
}
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;
}

// Determining If an Image Has Transparent Pixels
// This method returns true if the specified image has transparent pixels
public 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) {
e.printStackTrace();
}
// Get the image's color model
ColorModel cm = pg.getColorModel();
return cm.hasAlpha();
}

public static void main(String[] args) {
Image img = new ImageIcon("D:/a1.jpg").getImage();
System.out.println(write(img, new File("D:/adfasdsdf.jpg")));
}
}