工具类 - 图片处理

package net.shopxx.util;

import java.awt.AlphaComposite;
import java.awt.Color;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.util.Iterator;

import javax.imageio.ImageIO;
import javax.imageio.ImageReader;
import javax.imageio.stream.ImageInputStream;

import net.shopxx.bean.SystemConfig.WatermarkPosition;

/**
 * 工具类 - 图片处理
 * ============================================================================
 * 版权所有 2008-2010 长沙鼎诚软件有限公司，并保留所有权利。
 * ----------------------------------------------------------------------------
 * 提示：在未取得SHOP++商业授权之前，您不能将本软件应用于商业用途，否则SHOP++将保留追究的权力。
 * ----------------------------------------------------------------------------
 * 官方网站：http://www.shopxx.net
 * ----------------------------------------------------------------------------
 * KEY: SHOPXX5DA8E8F8C18FAC121CA036F5BF31C086
 * ============================================================================
 */

public class ImageUtil {

	/**
	 * 图片缩放(图片等比例缩放为指定大小，空白部分以白色填充)
	 * 
	 * @param srcBufferedImage
	 *            源图片
	 * @param destFile
	 *            缩放后的图片文件
	 */
	public static void zoom(BufferedImage srcBufferedImage, File destFile, int destHeight, int destWidth) {
		try {
			int imgWidth = destWidth;
			int imgHeight = destHeight;
			int srcWidth = srcBufferedImage.getWidth();
			int srcHeight = srcBufferedImage.getHeight();
			if (srcHeight >= srcWidth) {
				imgWidth = (int) Math.round(((destHeight * 1.0 / srcHeight) * srcWidth));
			} else {
				imgHeight = (int) Math.round(((destWidth * 1.0 / srcWidth) * srcHeight));
			}
			BufferedImage destBufferedImage = new BufferedImage(destWidth, destHeight, BufferedImage.TYPE_INT_RGB);
			Graphics2D graphics2D = destBufferedImage.createGraphics();
			graphics2D.setBackground(Color.WHITE);
			graphics2D.clearRect(0, 0, destWidth, destHeight);
			graphics2D.drawImage(srcBufferedImage.getScaledInstance(imgWidth, imgHeight, Image.SCALE_SMOOTH), (destWidth / 2) - (imgWidth / 2), (destHeight / 2) - (imgHeight / 2), null);
			graphics2D.dispose();
			ImageIO.write(destBufferedImage, "JPEG", destFile);
		} catch (IOException e) {
			e.printStackTrace();
		}
	}

	/**
	 * 添加图片水印
	 * 
	 * @param srcBufferedImage
	 *            需要处理的源图片
	 * @param destFile
	 *            处理后的图片文件
	 * @param watermarkFile
	 *            水印图片文件
	 * 
	 */
	public static void imageWatermark(BufferedImage srcBufferedImage, File destFile, File watermarkFile, WatermarkPosition watermarkPosition, int alpha) {
		try {
			int srcWidth = srcBufferedImage.getWidth();
			int srcHeight = srcBufferedImage.getHeight();
			BufferedImage destBufferedImage = new BufferedImage(srcWidth, srcHeight, BufferedImage.TYPE_INT_RGB);
			Graphics2D graphics2D = destBufferedImage.createGraphics();
			graphics2D.setBackground(Color.WHITE);
			graphics2D.clearRect(0, 0, srcWidth, srcHeight);
			graphics2D.drawImage(srcBufferedImage.getScaledInstance(srcWidth, srcHeight, Image.SCALE_SMOOTH), 0, 0, null);

			if (watermarkFile != null && watermarkFile.exists() && watermarkPosition != null && watermarkPosition != WatermarkPosition.no) {
				BufferedImage watermarkBufferedImage = ImageIO.read(watermarkFile);
				int watermarkImageWidth = watermarkBufferedImage.getWidth();
				int watermarkImageHeight = watermarkBufferedImage.getHeight();
				graphics2D.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_ATOP, alpha / 100.0F));
				int x = 0;
				int y = 0;
				if (watermarkPosition == WatermarkPosition.topLeft) {
					x = 0;
					y = 0;
				} else if (watermarkPosition == WatermarkPosition.topRight) {
					x = srcWidth - watermarkImageWidth;
					y = 0;
				} else if (watermarkPosition == WatermarkPosition.center) {
					x = (srcWidth - watermarkImageWidth) / 2;
					y = (srcHeight - watermarkImageHeight) / 2;
				} else if (watermarkPosition == WatermarkPosition.bottomLeft) {
					x = 0;
					y = srcHeight - watermarkImageHeight;
				} else if (watermarkPosition == WatermarkPosition.bottomRight) {
					x = srcWidth - watermarkImageWidth;
					y = srcHeight - watermarkImageHeight;
				}
				graphics2D.drawImage(watermarkBufferedImage, x, y, watermarkImageWidth, watermarkImageHeight, null);
			}
			graphics2D.dispose();
			ImageIO.write(destBufferedImage, "JPEG", destFile);
		} catch (Exception e) {
			e.printStackTrace();
		}
	}

	/**
	 * 图片缩放并添加图片水印(图片等比例缩放为指定大小，空白部分以白色填充)
	 * 
	 * @param srcBufferedImage
	 *            需要处理的图片
	 * @param destFile
	 *            处理后的图片文件
	 * @param watermarkFile
	 *            水印图片文件
	 * 
	 */
	public static void zoomAndWatermark(BufferedImage srcBufferedImage, File destFile, int destHeight, int destWidth, File watermarkFile, WatermarkPosition watermarkPosition, int alpha) {
		try {
			int imgWidth = destWidth;
			int imgHeight = destHeight;
			int srcWidth = srcBufferedImage.getWidth();
			int srcHeight = srcBufferedImage.getHeight();
			if (srcHeight >= srcWidth) {
				imgWidth = (int) Math.round(((destHeight * 1.0 / srcHeight) * srcWidth));
			} else {
				imgHeight = (int) Math.round(((destWidth * 1.0 / srcWidth) * srcHeight));
			}
			
			BufferedImage destBufferedImage = new BufferedImage(destWidth, destHeight, BufferedImage.TYPE_INT_RGB);
			Graphics2D graphics2D = destBufferedImage.createGraphics();
			graphics2D.setBackground(Color.WHITE);
			graphics2D.clearRect(0, 0, destWidth, destHeight);
			graphics2D.drawImage(srcBufferedImage.getScaledInstance(imgWidth, imgHeight, Image.SCALE_SMOOTH), (destWidth / 2) - (imgWidth / 2), (destHeight / 2) - (imgHeight / 2), null);
			if (watermarkFile != null && watermarkFile.exists() && watermarkPosition != null && watermarkPosition != WatermarkPosition.no) {
				BufferedImage watermarkBufferedImage = ImageIO.read(watermarkFile);
				int watermarkImageWidth = watermarkBufferedImage.getWidth();
				int watermarkImageHeight = watermarkBufferedImage.getHeight();
				graphics2D.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_ATOP, alpha / 100.0F));
				int x = 0;
				int y = 0;
				if (watermarkPosition == WatermarkPosition.topLeft) {
					x = 0;
					y = 0;
				} else if (watermarkPosition == WatermarkPosition.topRight) {
					x = destWidth - watermarkImageWidth;
					y = 0;
				} else if (watermarkPosition == WatermarkPosition.center) {
					x = (destWidth - watermarkImageWidth) / 2;
					y = (destHeight - watermarkImageHeight) / 2;
				} else if (watermarkPosition == WatermarkPosition.bottomLeft) {
					x = 0;
					y = destHeight - watermarkImageHeight;
				} else if (watermarkPosition == WatermarkPosition.bottomRight) {
					x = destWidth - watermarkImageWidth;
					y = destHeight - watermarkImageHeight;
				}
				graphics2D.drawImage(watermarkBufferedImage, x, y, watermarkImageWidth, watermarkImageHeight, null);
			}
			graphics2D.dispose();
			ImageIO.write(destBufferedImage, "JPEG", destFile);
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
	
	/**
	 * 获取图片文件的类型.
	 * 
	 * @param imageFile
	 *            图片文件对象.
	 * @return 图片文件类型
	 */
	public static String getImageFormatName(File imageFile) {
		try {
			ImageInputStream imageInputStream = ImageIO.createImageInputStream(imageFile);
			Iterator<ImageReader> iterator = ImageIO.getImageReaders(imageInputStream);
			if (!iterator.hasNext()) {
				return null;
			}
			ImageReader imageReader = (ImageReader) iterator.next();
			imageInputStream.close();
			return imageReader.getFormatName().toLowerCase();
		} catch (IOException e) {
			e.printStackTrace();
		}
		return null;
	}

}