数据库存取工具

package util;

import java.awt.Graphics;
import java.awt.Image;
import java.awt.Label;
import java.awt.MediaTracker;
import java.awt.Toolkit;
import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.io.IOException;

import javax.imageio.ImageIO;

/**
 * 这个工具类用于向数据库存入图片，以及从数据库得到图片。
 */
public class DatabaseRead_GetImage {

	/**
	 * 转换Image数据为byte数组
	 * 
	 * @param image
	 *            Image对象
	 * @param format
	 *            image格式字符串.如 "jpeg ", "png "
	 * @return byte数组
	 */
	public static byte[] imageToBytes(Image image, String format) {
		BufferedImage bImage = new BufferedImage(image.getWidth(null), image
				.getHeight(null), BufferedImage.TYPE_INT_ARGB);
		Graphics bg = bImage.getGraphics();
		bg.drawImage(image, 0, 0, null);
		bg.dispose();

		ByteArrayOutputStream out = new ByteArrayOutputStream();
		try {
			ImageIO.write(bImage, format, out);
		} catch (IOException e) {
			e.printStackTrace();
		}
		return out.toByteArray();
	}

	/**
	 * 转换byte数组为Image
	 * 
	 * @param bytes
	 *            Image的bytes数据数组
	 * @return Image
	 */
	public static Image bytesToImage(byte[] bytes) {
		Image image = Toolkit.getDefaultToolkit().createImage(bytes);

		try {
			MediaTracker mt = new MediaTracker(new Label());
			mt.addImage(image, 0);
			mt.waitForAll();
		} catch (InterruptedException e) {
			e.printStackTrace();
		}

		return image;
	}
}