Java水印图片处理

今天需要用Java程序给图片加水印，于是在网上找到了一段代码，感觉很好，于是记录了下来，原来的网址给忘了：

 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;

 /**
  * 图片工具类， 图片水印，文字水印，缩放，补白等
  *
  * @author Carl He
  */
 public final class ImageUtils {
     /** 图片格式：JPG */
     private static final String PICTRUE_FORMATE_JPG = "jpg";

     private ImageUtils() {
     }

     /**
      * 添加图片水印
      *
      * @param targetImg
      *            目标图片路径，如：C://myPictrue//1.jpg
      * @param waterImg
      *            水印图片路径，如：C://myPictrue//logo.png
      * @param x
      *            水印图片距离目标图片左侧的偏移量，如果x<0, 则在正中间
      * @param y
      *            水印图片距离目标图片上侧的偏移量，如果y<0, 则在正中间
      * @param alpha
      *            透明度(0.0 -- 1.0, 0.0为完全透明，1.0为完全不透明)
      */
     public final static void pressImage(String targetImg, String waterImg,
             int x, int y, float alpha) {
         try {
             File file = new File(targetImg);
             Image image = ImageIO.read(file);
             int width = image.getWidth(null);
             int height = image.getHeight(null);
             BufferedImage bufferedImage = new BufferedImage(width, height,
                     BufferedImage.TYPE_INT_RGB);
             Graphics2D g = bufferedImage.createGraphics();
             g.drawImage(image, 0, 0, width, height, null);

             Image waterImage = ImageIO.read(new File(waterImg)); // 水印文件
             int width_1 = waterImage.getWidth(null);
             int height_1 = waterImage.getHeight(null);
             g.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_ATOP,
                     alpha));

             int widthDiff = width - width_1;
             int heightDiff = height - height_1;
             if (x < 0) {
                 x = widthDiff / 2;
             } else if (x > widthDiff) {
                 x = widthDiff;
             }
             if (y < 0) {
                 y = heightDiff / 2;
             } else if (y > heightDiff) {
                 y = heightDiff;
             }
             g.drawImage(waterImage, x, y, width_1, height_1, null); // 水印文件结束
             g.dispose();
             ImageIO.write(bufferedImage, PICTRUE_FORMATE_JPG, file);
         } catch (IOException e) {
             e.printStackTrace();
         }
     }

     /**
      * 添加文字水印
      *
      * @param targetImg
      *            目标图片路径，如：C://myPictrue//1.jpg
      * @param pressText
      *            水印文字， 如：中国证券网
      * @param fontName
      *            字体名称， 如：宋体
      * @param fontStyle
      *            字体样式，如：粗体和斜体(Font.BOLD|Font.ITALIC)
      * @param fontSize
      *            字体大小，单位为像素
      * @param color
      *            字体颜色
      * @param x
      *            水印文字距离目标图片左侧的偏移量，如果x<0, 则在正中间
      * @param y
      *            水印文字距离目标图片上侧的偏移量，如果y<0, 则在正中间
      * @param alpha
      *            透明度(0.0 -- 1.0, 0.0为完全透明，1.0为完全不透明)
      */
     public static void pressText(String targetImg, String pressText,
             String fontName, int fontStyle, int fontSize, Color color, int x,
             int y, float alpha) {
         try {
             File file = new File(targetImg);

             Image image = ImageIO.read(file);
             int width = image.getWidth(null);
             int height = image.getHeight(null);
             BufferedImage bufferedImage = new BufferedImage(width, height,
                     BufferedImage.TYPE_INT_RGB);
             Graphics2D g = bufferedImage.createGraphics();
             g.drawImage(image, 0, 0, width, height, null);
             g.setFont(new Font(fontName, fontStyle, fontSize));
             g.setColor(color);
             g.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_ATOP,
                     alpha));

             int width_1 = fontSize * getLength(pressText);
             int height_1 = fontSize;
             int widthDiff = width - width_1;
             int heightDiff = height - height_1;
             if (x < 0) {
                 x = widthDiff / 2;
             } else if (x > widthDiff) {
                 x = widthDiff;
             }
             if (y < 0) {
                 y = heightDiff / 2;
             } else if (y > heightDiff) {
                 y = heightDiff;
             }

             g.drawString(pressText, x, y + height_1);
             g.dispose();
             ImageIO.write(bufferedImage, PICTRUE_FORMATE_JPG, file);
         } catch (Exception e) {
             e.printStackTrace();
         }
     }

     /**
      * 获取字符长度，一个汉字作为 1 个字符, 一个英文字母作为 0.5 个字符
      *
      * @param text
      * @return 字符长度，如：text="中国",返回 2；text="test",返回 2；text="中国ABC",返回 4.
      */
     public static int getLength(String text) {
         int textLength = text.length();
         int length = textLength;
         for (int i = 0; i < textLength; i++) {
             if (String.valueOf(text.charAt(i)).getBytes().length > 1) {
                 length++;
             }
         }
         return (length % 2 == 0) ? length / 2 : length / 2 + 1;
     }

     /**
      * 图片缩放
      *
      * @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,
                     BufferedImage.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("C://pic//jpg", "C://pic//test.gif", 5000, 5000, 0f);
         pressText("C://pic//jpg", "旺仔之印", "宋体", Font.BOLD | Font.ITALIC, 20,
                 Color.BLACK, 0, 0, 8f);
         resize("C://pic//4.jpg", 1000, 500, true);
     }
 }