[转]Java缩略图类带水印（jpg,png）

 

package com.example;
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.geom.AffineTransform;
import java.awt.image.BufferedImage;
import java.awt.image.ColorModel;
import java.awt.image.WritableRaster;
import java.io.File;
import java.io.FileOutputStream;
import javax.imageio.ImageIO;
import com.sun.image.codec.jpeg.JPEGCodec;
import com.sun.image.codec.jpeg.JPEGImageEncoder;

public class ImageHelper {

        /**
         * 生成缩略图 <br/>保存:ImageIO.write(BufferedImage, imgType[jpg/png/...], File);
         * 
         * @param source
         *            原图片
         * @param width
         *            缩略图宽
         * @param height
         *            缩略图高
         * @param b
         *            是否等比缩放
         * */
        public static BufferedImage Thumb(BufferedImage source, int width,
                        int height, boolean b) {
                // targetW，targetH分别表示目标长和宽
                int type = source.getType();
                BufferedImage target = null;
                double sx = (double) width / source.getWidth();
                double sy = (double) height / source.getHeight();

                if (b) {
                        if (sx > sy) {
                                sx = sy;
                                width = (int) (sx * source.getWidth());
                        } else {
                                sy = sx;
                                height = (int) (sy * source.getHeight());
                        }
                }
                
                if (type == BufferedImage.TYPE_CUSTOM) { // handmade
                        ColorModel cm = source.getColorModel();
                        WritableRaster raster = cm.createCompatibleWritableRaster(width,
                                        height);
                        boolean alphaPremultiplied = cm.isAlphaPremultiplied();
                        target = new BufferedImage(cm, raster, alphaPremultiplied, null);
                } else
                        target = new BufferedImage(width, height, type);
                Graphics2D g = target.createGraphics();
                // smoother than exlax:
                g.setRenderingHint(RenderingHints.KEY_RENDERING,
                                RenderingHints.VALUE_RENDER_QUALITY);
                g.drawRenderedImage(source, AffineTransform.getScaleInstance(sx, sy));
                g.dispose();
                return target;
        }

        /**
         * 图片水印
         * 
         * @param imgPath
         *            待处理图片
         * @param markPath
         *            水印图片
         * @param x
         *            水印位于图片左上角的 x 坐标值
         * @param y
         *            水印位于图片左上角的 y 坐标值
         * @param alpha
         *            水印透明度 0.1f ~ 1.0f
         * */
        public static void waterMark(String imgPath, String markPath, int x, int y,
                        float alpha) {
                try {
                        // 加载待处理图片文件
                        Image img = ImageIO.read(new File(imgPath));

                        BufferedImage image = new BufferedImage(img.getWidth(null), img
                                        .getHeight(null), BufferedImage.TYPE_INT_RGB);
                        Graphics2D g = image.createGraphics();
                        g.drawImage(img, 0, 0, null);

                        // 加载水印图片文件
                        Image src_biao = ImageIO.read(new File(markPath));
                        g.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_ATOP,
                                        alpha));
                        g.drawImage(src_biao, x, y, null);
                        g.dispose();

                        // 保存处理后的文件
                        FileOutputStream out = new FileOutputStream(imgPath);
                        JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);
                        encoder.encode(image);
                        out.close();
                } catch (Exception e) {
                        e.printStackTrace();
                }
        }

        /**
         * 文字水印
         * 
         * @param imgPath
         *            待处理图片
         * @param text
         *            水印文字
         * @param font
         *            水印字体信息
         * @param color
         *            水印字体颜色
         * @param x
         *            水印位于图片左上角的 x 坐标值
         * @param y
         *            水印位于图片左上角的 y 坐标值
         * @param alpha
         *            水印透明度 0.1f ~ 1.0f
         */

        public static void textMark(String imgPath, String text, Font font,
                        Color color, int x, int y, float alpha) {
                try {
                        Font Dfont = (font == null) ? new Font("宋体", 20, 13) : font;

                        Image img = ImageIO.read(new File(imgPath));

                        BufferedImage image = new BufferedImage(img.getWidth(null), img
                                        .getHeight(null), BufferedImage.TYPE_INT_RGB);
                        Graphics2D g = image.createGraphics();

                        g.drawImage(img, 0, 0, null);
                        g.setColor(color);
                        g.setFont(Dfont);
                        g.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_ATOP,
                                        alpha));
                        g.drawString(text, x, y);
                        g.dispose();
                        FileOutputStream out = new FileOutputStream(imgPath);
                        JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);
                        encoder.encode(image);
                        out.close();
                } catch (Exception e) {
                        System.out.println(e);
                }
        }
}