imageutils.java

用Hibernate开发的JiveJdon

package com.jdon.jivejdon.util;

import java.awt.Dimension;
import java.awt.Image;
import java.awt.image.BufferedImage;
import java.awt.image.PixelGrabber;
import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.Iterator;
import java.util.Locale;

import javax.imageio.IIOImage;
import javax.imageio.ImageIO;
import javax.imageio.ImageWriteParam;
import javax.imageio.ImageWriter;
import javax.imageio.plugins.jpeg.JPEGImageWriteParam;
import javax.imageio.stream.ImageOutputStream;

import org.apache.struts.upload.FormFile;




public class ImageUtils {
	
	public static final int IMAGE_UNKNOWN = -1;
	public static final int IMAGE_JPEG = 0;
	public static final int IMAGE_PNG = 1;
	public static final int IMAGE_GIF = 2;

	
	public static void saveUploadedFile(FormFile theFile,String filename)
	{
		BufferedInputStream inputStream = null;
		FileOutputStream outputStream = null;

		try {
			inputStream = new BufferedInputStream(theFile.getInputStream());
			outputStream = new FileOutputStream(filename);
			
			int c;
			byte[] b = new byte[4096];
			while ((c = inputStream.read(b)) != -1) {
				outputStream.write(b, 0, c);
			}
		}
		catch (IOException e) {
			e.printStackTrace();
		}
		finally {
			if (outputStream != null) {
				try {
					outputStream.flush();
					outputStream.close();
				}
				catch (IOException e) { }
			}

			if (inputStream != null) {
				try {
					inputStream.close();
				}
				catch (IOException e) { }
			}
		}
	}
	
	public static BufferedImage resizeImage(String imgName, int type, int maxWidth, int maxHeight)throws IOException {
		return resizeImage(ImageIO.read(new File(imgName)), type, maxWidth, maxHeight);
	}

	public static BufferedImage resizeImage(BufferedImage image, int type, int maxWidth, int maxHeight) {
		Dimension largestDimension = new Dimension(maxWidth, maxHeight);

		// Original size
		int imageWidth = image.getWidth(null);
		int imageHeight = image.getHeight(null);

		float aspectRatio = (float) imageWidth / imageHeight;

		if (imageWidth > maxWidth || imageHeight > maxHeight) {
			if ((float) largestDimension.width / largestDimension.height > aspectRatio) {
				largestDimension.width = (int) Math.ceil(largestDimension.height * aspectRatio);
			}
			else {
				largestDimension.height = (int) Math.ceil(largestDimension.width / aspectRatio);
			}

			imageWidth = largestDimension.width;
			imageHeight = largestDimension.height;
		}

		return createHeadlessSmoothBufferedImage(image, type, imageWidth, imageHeight);
	}

	public static boolean saveImage(BufferedImage image, String toFileName, int type)throws IOException {
			return ImageIO.write(image, type == IMAGE_JPEG ? "jpg" : "png", new File(toFileName));
	}

	public static void saveCompressedImage(BufferedImage image, String toFileName, int type)
	{
		try {
			if (type == IMAGE_PNG) {
				throw new UnsupportedOperationException("PNG compression not implemented");
			}

			Iterator iter = ImageIO.getImageWritersByFormatName("jpg");
			ImageWriter writer;
			writer = (ImageWriter) iter.next();

			ImageOutputStream ios = ImageIO.createImageOutputStream(new File(toFileName));
			writer.setOutput(ios);

			ImageWriteParam iwparam = new JPEGImageWriteParam(Locale.getDefault());

			iwparam.setCompressionMode(ImageWriteParam.MODE_EXPLICIT);
			iwparam.setCompressionQuality(0.7F);

			writer.write(null, new IIOImage(image, null, null), iwparam);

			ios.flush();
			writer.dispose();
			ios.close();
		}
		catch (IOException e) {
			e.printStackTrace();
		}
	}

	public static BufferedImage createHeadlessBufferedImage(BufferedImage image, int type, int width, int height)
	{
		if (type == ImageUtils.IMAGE_PNG && hasAlpha(image)) {
			type = BufferedImage.TYPE_INT_ARGB;
		}
		else {
			type = BufferedImage.TYPE_INT_RGB;
		}

		BufferedImage bi = new BufferedImage(width, height, type);

		for (int y = 0; y < height; y++) {
			for (int x = 0; x < width; x++) {
				bi.setRGB(x, y, image.getRGB(x * image.getWidth() / width, y * image.getHeight() / height));
			}
		}

		return bi;
	}


	public static BufferedImage createHeadlessSmoothBufferedImage(BufferedImage source, int type, int width, int height)
	{
		if (type == ImageUtils.IMAGE_PNG && hasAlpha(source)) {
			type = BufferedImage.TYPE_INT_ARGB;
		}
		else {
			type = BufferedImage.TYPE_INT_RGB;
		}

		BufferedImage dest = new BufferedImage(width, height, type);

		int sourcex;
		int sourcey;

		double scalex = (double) width / source.getWidth();
		double scaley = (double) height / source.getHeight();

		int x1;
		int y1;

		double xdiff;
		double ydiff;

		int rgb;
		int rgb1;
		int rgb2;

		for (int y = 0; y < height; y++) {
			sourcey = y * source.getHeight() / dest.getHeight();
			ydiff = scale(y, scaley) - sourcey;

			for (int x = 0; x < width; x++) {
				sourcex = x * source.getWidth() / dest.getWidth();
				xdiff = scale(x, scalex) - sourcex;

				x1 = Math.min(source.getWidth() - 1, sourcex + 1);
				y1 = Math.min(source.getHeight() - 1, sourcey + 1);

				rgb1 = getRGBInterpolation(source.getRGB(sourcex, sourcey), source.getRGB(x1, sourcey), xdiff);
				rgb2 = getRGBInterpolation(source.getRGB(sourcex, y1), source.getRGB(x1, y1), xdiff);

				rgb = getRGBInterpolation(rgb1, rgb2, ydiff);

				dest.setRGB(x, y, rgb);
			}
		}

		return dest;
	}

	private static double scale(int point, double scale)
	{
		return point / scale;
	}

	private static int getRGBInterpolation(int value1, int value2, double distance)
	{
		int alpha1 = (value1 & 0xFF000000) >>> 24;
		int red1 = (value1 & 0x00FF0000) >> 16;
		int green1 = (value1 & 0x0000FF00) >> 8;
		int blue1 = (value1 & 0x000000FF);

		int alpha2 = (value2 & 0xFF000000) >>> 24;
		int red2 = (value2 & 0x00FF0000) >> 16;
		int green2 = (value2 & 0x0000FF00) >> 8;
		int blue2 = (value2 & 0x000000FF);

		int rgb = ((int) (alpha1 * (1.0 - distance) + alpha2 * distance) << 24)
			| ((int) (red1 * (1.0 - distance) + red2 * distance) << 16)
			| ((int) (green1 * (1.0 - distance) + green2 * distance) << 8)
			| (int) (blue1 * (1.0 - distance) + blue2 * distance);

		return rgb;
	}

	/**
	 * Determines if the image has transparent pixels.
	 * 
	 * @param image The image to check for transparent pixel.s
	 * @return <code>true</code> of <code>false</code>, according to the result
	 */
	public static boolean hasAlpha(Image image)
	{
		try {
			PixelGrabber pg = new PixelGrabber(image, 0, 0, 1, 1, false);
			pg.grabPixels();

			return pg.getColorModel().hasAlpha();
		}
		catch (InterruptedException e) {
			return false;
		}
	}
	
}