我正在尝试将 Image 对象转换为字节数组，然后再转换回 Image（以便我可以将图像存储在 Apache Derby 数据库中的 blob 对象中）。
我可以将图像转换为字节数组（下面的代码），但我无法将字节转换回图像。更复杂的是，我使用的是 J2ME，所以我不能使用 javax.image.*。你能帮我吗？
谢谢
package six.util;
import java.awt.Image;
import java.awt.image.BufferedImage;
import java.awt.image.ImageObserver;
import java.awt.Component;
import java.awt.MediaTracker;
import java.awt.Graphics;
import java.awt.image.DataBufferByte;
import java.awt.image.WritableRaster;
import java.awt.GraphicsConfiguration;
import java.awt.GraphicsDevice;
import java.awt.GraphicsEnvironment;
import java.awt.image.PixelGrabber;
import java.util.ArrayList;
public class ImageConverter extends Component
{
private MediaTracker mediaTracker;
private Image image;
private ImageConverter(Image image)
{
super();
this.mediaTracker = new MediaTracker(this);
this.mediaTracker.addImage(image, 0);
this.image = image;
}
private BufferedImage convert()
{
/*
* Have to wait for image to load.
*/
try
{
this.mediaTracker.waitForID(0);
}catch(InterruptedException e)
{
}
System.out.println("-1");
GraphicsConfiguration graphicsConfig = GraphicsEnvironment.getLocalGraphicsEnvironment().getDefaultScreenDevice().getDefaultConfiguration();
BufferedImage bimage = graphicsConfig.createCompatibleImage(this.image.getWidth(null),this.image.getHeight(null));
System.out.println("-2");
Graphics g = bimage.getGraphics();
g.drawImage(image, 0, 0, null);
return bimage;
}
private static byte[] convertIntToByteArray(int integer)
{
byte[] bytes = new byte[4];
bytes[0] =(byte)( integer >> 24 );
bytes[1] =(byte)( (integer << 8) >> 24 );
bytes[2] =(byte)( (integer << 16) >> 24 );
bytes[3] =(byte)( (integer << 24) >> 24 );
return bytes;
}
private static int convertByteArrayToInt(byte[] bytes)
{
return (bytes[0] << 32) | (bytes[1] << 24) | (bytes[2] << 16) | (bytes[3] << 8) | bytes[4];
}
private static byte[] convertIntArrayToByteArray(int[] integers)
{
byte[] bytes = new byte[integers.length*4];
for (int index = 0; index < integers.length; index++)
{
byte[] integerBytes = convertIntToByteArray(integers[index]);
bytes[index*4] = integerBytes[0];
bytes[1 + (index*4)] = integerBytes[1];
bytes[2 + (index*4)] = integerBytes[2];
bytes[3 + (index*4)] = integerBytes[3];
}
return bytes;
}
private static int[] convertByteArrayToIntArray(byte[] bytes)
{
ArrayList integers = new ArrayList();
for (int index = 0; index < bytes.length; index += 4)
{
byte[] fourBytes = new byte[4];
fourBytes[0] = bytes[index];
fourBytes[1] = bytes[index+1];
fourBytes[2] = bytes[index+2];
fourBytes[3] = bytes[index+3];
int integer = convertByteArrayToInt(fourBytes);
integers.add(new Integer(integer));
}
int[] ints = new int[bytes.length/4];
for (int index = 0; index < integers.size() ; index++)
{
ints[index] = ((Integer)integers.get(index)).intValue();
}
return ints;
}
public static byte[] convertToBytes(Image image)
{
System.out.println("A");
ImageConverter converter = new ImageConverter(image);
System.out.println("B");
BufferedImage bufferedImage = converter.convert();
System.out.println("C");
PixelGrabber pixelGrabber = new PixelGrabber(image,0,0,bufferedImage.getWidth(),bufferedImage.getHeight(),true);
System.out.println("D");
try
{
if(pixelGrabber.grabPixels())
{
Object pixels = pixelGrabber.getPixels();
if (pixels instanceof byte[])
{
return (byte[])pixels;
}
return convertIntArrayToByteArray((int[])pixels);
}
}catch(InterruptedException e)
{
}
return null;
}
}