java实现给图片添加水印、透明度

package michael.io.image;   
  
import java.awt.AlphaComposite;   
import java.awt.Graphics2D;   
import java.awt.Image;   
import java.awt.RenderingHints;   
import java.awt.image.BufferedImage;   
import java.io.File;   
import java.io.FileInputStream;   
import java.io.FileOutputStream;   
import java.io.InputStream;   
import java.io.OutputStream;   
  
import javax.imageio.ImageIO;   
import javax.swing.ImageIcon;   
  
import com.sun.image.codec.jpeg.JPEGCodec;   
import com.sun.image.codec.jpeg.JPEGImageDecoder;   
import com.sun.image.codec.jpeg.JPEGImageEncoder;   
  
/**  
 * 图片水印  
 * @blog http://sjsky.iteye.com  
 * @author Michael  
 */  
public class ImageMarkLogoByIcon {   
  
    /**  
     * @param args  
     */  
    public static void main(String[] args) {   
        String srcImgPath = "d:/test/michael/myblog_01.png";   
        String iconPath = "d:/test/michael/blog_logo.png";   
        String targerPath = "d:/test/michael/img_mark_icon.jpg";   
        String targerPath2 = "d:/test/michael/img_mark_icon_rotate.jpg";   
        // 给图片添加水印   
        ImageMarkLogoByIcon.markImageByIcon(iconPath, srcImgPath, targerPath);   
        // 给图片添加水印,水印旋转-45   
        ImageMarkLogoByIcon.markImageByIcon(iconPath, srcImgPath, targerPath2,   
                -45);   
  
    }   
  
    /**  
     * 给图片添加水印  
     * @param iconPath 水印图片路径  
     * @param srcImgPath 源图片路径  
     * @param targerPath 目标图片路径  
     */  
    public static void markImageByIcon(String iconPath, String srcImgPath,   
            String targerPath) {   
        markImageByIcon(iconPath, srcImgPath, targerPath, null);   
    }   
  
    /**  
     * 给图片添加水印、可设置水印图片旋转角度  
     * @param iconPath 水印图片路径  
     * @param srcImgPath 源图片路径  
     * @param targerPath 目标图片路径  
     * @param degree 水印图片旋转角度  
     */  
    public static void markImageByIcon(String iconPath, String srcImgPath,   
            String targerPath, Integer degree) {   
        OutputStream os = null;   
        try {   
            Image srcImg = ImageIO.read(new File(srcImgPath));   
  
            BufferedImage buffImg = new BufferedImage(srcImg.getWidth(null),   
                    srcImg.getHeight(null), BufferedImage.TYPE_INT_RGB);   
  
            // 得到画笔对象   
            // Graphics g= buffImg.getGraphics();   
            Graphics2D g = buffImg.createGraphics();   
  
            // 设置对线段的锯齿状边缘处理   
            g.setRenderingHint(RenderingHints.KEY_INTERPOLATION,   
                    RenderingHints.VALUE_INTERPOLATION_BILINEAR);   
  
            g.drawImage(srcImg.getScaledInstance(srcImg.getWidth(null), srcImg   
                    .getHeight(null), Image.SCALE_SMOOTH), 0, 0, null);   
  
            if (null != degree) {   
                // 设置水印旋转   
                g.rotate(Math.toRadians(degree),   
                        (double) buffImg.getWidth() / 2, (double) buffImg   
                                .getHeight() / 2);   
            }   
  
            // 水印图象的路径 水印一般为gif或者png的，这样可设置透明度   
            ImageIcon imgIcon = new ImageIcon(iconPath);   
  
            // 得到Image对象。   
            Image img = imgIcon.getImage();   
  
            float alpha = 0.5f; // 透明度   
            g.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_ATOP,   
                    alpha));   
  
            // 表示水印图片的位置   
            g.drawImage(img, 150, 300, null);   
  
            g.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_OVER));   
  
            g.dispose();   
  
            os = new FileOutputStream(targerPath);   
  
            // 生成图片   
            ImageIO.write(buffImg, "JPG", os);   
  
            System.out.println("图片完成添加Icon印章。。。。。。");   
        } catch (Exception e) {   
            e.printStackTrace();   
        } finally {   
            try {   
                if (null != os)   
                    os.close();   
            } catch (Exception e) {   
                e.printStackTrace();   
            }   
        }   
    }   
}