java图片文字水印、图片水印、缩放、补白处理

package com.hmw.picMark;      
     
import java.awt.AlphaComposite;      
import java.awt.Color;      
import java.awt.Font;      
import java.awt.Graphics2D;      
import java.awt.Image;      
import java.awt.geom.AffineTransform;      
import java.awt.image.AffineTransformOp;      
import java.awt.image.BufferedImage;      
import java.io.File;      
import java.io.IOException;      
     
import javax.imageio.ImageIO;      
     
     
public final class ImageUtils {      
    /**    
     * 图片水印    
     *     
     * @param pressImg    
     *            水印图片    
     * @param targetImg    
     *            目标图片    
     * @param x    
     *            修正值 默认在中间    
     * @param y    
     *            修正值 默认在中间    
     * @param alpha    
     *            透明度    
     */     
    public final static void pressImage(String pressImg, String targetImg, int x, int y, float alpha) {      
        try {      
            File img = new File(targetImg);      
            Image src = ImageIO.read(img);      
            int wideth = src.getWidth(null);      
            int height = src.getHeight(null);      
            BufferedImage image = new BufferedImage(wideth, height, BufferedImage.TYPE_INT_RGB);      
            Graphics2D g = image.createGraphics();      
            g.drawImage(src, 0, 0, wideth, height, null);      
            // 水印文件      
            Image src_biao = ImageIO.read(new File(pressImg));      
            int wideth_biao = src_biao.getWidth(null);      
            int height_biao = src_biao.getHeight(null);      
            g.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_ATOP, alpha));      
            g.drawImage(src_biao, (wideth - wideth_biao) / 2, (height - height_biao) / 2, wideth_biao, height_biao, null);      
            // 水印文件结束      
            g.dispose();      
            ImageIO.write((BufferedImage) image, "jpg", img);      
        } catch (Exception e) {      
            e.printStackTrace();      
        }      
    }      
     
    /**    
     * 文字水印    
     *     
     * @param pressText    
     *            水印文字    
     * @param targetImg    
     *            目标图片    
     * @param fontName    
     *            字体名称    
     * @param fontStyle    
     *            字体样式    
     * @param color    
     *            字体颜色    
     * @param fontSize    
     *            字体大小    
     * @param x    
     *            修正值    
     * @param y    
     *            修正值    
     * @param alpha    
     *            透明度    
     */     
    public static void pressText(String pressText, String targetImg, String fontName, int fontStyle, Color color, int fontSize, int x, int y, float alpha) {      
        try {      
            File img = new File(targetImg);      
            Image src = ImageIO.read(img);      
            int width = src.getWidth(null);      
            int height = src.getHeight(null);      
            BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);      
            Graphics2D g = image.createGraphics();      
            g.drawImage(src, 0, 0, width, height, null);      
            g.setColor(color);      
            g.setFont(new Font(fontName, fontStyle, fontSize));      
            g.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_ATOP, alpha));      
            g.drawString(pressText, (width - (getLength(pressText) * fontSize)) / 2 + x, (height - fontSize) / 2 + y);      
            g.dispose();      
            ImageIO.write((BufferedImage) image, "jpg", img);      
        } catch (Exception e) {      
            e.printStackTrace();      
        }      
    }      
     
    /**    
     * 缩放    
     *     
     * @param filePath    
     *            图片路径    
     * @param height    
     *            高度    
     * @param width    
     *            宽度    
     * @param bb    
     *            比例不对时是否需要补白    
     */     
    public static void resize(String filePath, int height, int width, boolean bb) {      
        try {      
            double ratio = 0; // 缩放比例      
            File f = new File(filePath);      
            BufferedImage bi = ImageIO.read(f);      
            Image itemp = bi.getScaledInstance(width, height, bi.SCALE_SMOOTH);      
            // 计算比例      
            if ((bi.getHeight() > height) || (bi.getWidth() > width)) {      
                if (bi.getHeight() > bi.getWidth()) {      
                    ratio = (new Integer(height)).doubleValue() / bi.getHeight();      
                } else {      
                    ratio = (new Integer(width)).doubleValue() / bi.getWidth();      
                }      
                AffineTransformOp op = new AffineTransformOp(AffineTransform.getScaleInstance(ratio, ratio), null);      
                itemp = op.filter(bi, null);      
            }      
            if (bb) {      
                BufferedImage image = new BufferedImage(width, height,      
                        BufferedImage.TYPE_INT_RGB);      
                Graphics2D g = image.createGraphics();      
                g.setColor(Color.white);      
                g.fillRect(0, 0, width, height);      
                if (width == itemp.getWidth(null))      
                    g.drawImage(itemp, 0, (height - itemp.getHeight(null)) / 2, itemp.getWidth(null), itemp.getHeight(null), Color.white, null);      
                else     
                    g.drawImage(itemp, (width - itemp.getWidth(null)) / 2, 0, itemp.getWidth(null), itemp.getHeight(null), Color.white, null);      
                g.dispose();      
                itemp = image;      
            }      
            ImageIO.write((BufferedImage) itemp, "jpg", f);      
        } catch (IOException e) {      
            e.printStackTrace();      
        }      
    }      
     
    public static void main(String[] args) throws IOException {      
        pressImage("G:\\imgtest\\sy.jpg", "G:\\imgtest\\testjpg", 0, 0, 5f);      
        pressText("我是文字水印", "G:\\imgtest\\testjpg", "黑体", 36, Color.white, 80,      
                0, 0, 3f);      
        resize("G:\\imgtest\\testjpg", 500, 500, true);      
    }      
     
    public static int getLength(String text) {      
        int length = 0;      
        for (int i = 0; i < text.length(); i++) {      
            if (new String(text.charAt(i) + "").getBytes().length > 1) {      
                length += 2;      
            } else {      
                length += 1;      
            }      
        }      
        return length / 2;      
    }      
}