java.imageIo给图片添加水印的实现代码

代码如下：

package com.blogs.image;
import java.awt.AlphaComposite;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.RenderingHints;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import javax.imageio.ImageIO;
import javax.swing.ImageIcon;
/**
 * 图片水印
 */
public class ImageUtil {
    /**
     * @param args
     */
    public static void main(String[] args) {
        String srcImgPath = "e:/2.png";
        String iconPath = "e:\logo.jpg";
        String targerPath = "e:/3.jpg";
        // 给图片添加水印
        ImageUtil.waterMarkImageByIcon(iconPath, srcImgPath, targerPath, 0, 0,
, 0.1f);
        // 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、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
     * @param width
     *            宽度(与左相比)
     * @param height
     *            高度(与顶相比)
     * @param clarity
     *            透明度(小于1的数)越接近0越透明
     */
    public static void waterMarkImageByIcon(String iconPath, String srcImgPath,
            String targerPath, Integer degree, Integer width, Integer height,
            float clarity) {
        OutputStream os = null;
        try {
            Image srcImg = ImageIO.read(new File(srcImgPath));
            System.out.println("width:" + srcImg.getWidth(null));
            System.out.println("height:" + srcImg.getHeight(null));
            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 = clarity; // 透明度
            g.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_ATOP,
                    alpha));
            // 表示水印图片的位置
            g.drawImage(img, width, height, 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("添加水印图片完成!");
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                if (null != os)
                    os.close();
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }
    /**
     * 给图片添加水印、可设置水印图片旋转角度
     *
     * @param logoText
     *            水印文字
     * @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
     * @param width
     *            宽度(与左相比)
     * @param height
     *            高度(与顶相比)
     * @param clarity
     *            透明度(小于1的数)越接近0越透明
     */
    public static void waterMarkByText(String logoText, String srcImgPath,
            String targerPath, Integer degree, Integer width, Integer height,
            Float clarity) {
        // 主图片的路径
        InputStream is = null;
        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);
            }
            // 设置颜色
            g.setColor(Color.red);
            // 设置 Font
            g.setFont(new Font("宋体", Font.BOLD, 30));
            float alpha = clarity;
            g.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_ATOP,
                    alpha));
            // 第一参数-设置的内容，后面两个参数-文字在图片上的坐标位置(x,y) .
            g.drawString(logoText, width, height);
            g.dispose();
            os = new FileOutputStream(targerPath);
            // 生成图片
            ImageIO.write(buffImg, "JPG", os);
            System.out.println("添加水印文字完成!");
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                if (null != is)
                    is.close();
            } catch (Exception e) {
                e.printStackTrace();
            }
            try {
                if (null != os)
                    os.close();
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }
}

还有一个图片缩放代码:
代码如下：

/**
     * 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 srcPath
     *            源图片路径
     * @param destPath
     *            缩放后图片路径
     */
    public static void zoomImage(String srcPath, String destPath, int destHeight, int destWidth) {
        try {
            BufferedImage srcBufferedImage = ImageIO.read(new File(srcPath));
            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", new File(destPath));
        } catch (IOException e) {
            e.printStackTrace();
        }
    }