java：给图片上加水印

import java.awt.Color;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.image.BufferedImage;
import java.io.FileOutputStream;

import javax.swing.ImageIcon;

import com.sun.image.codec.jpeg.JPEGCodec;
import com.sun.image.codec.jpeg.JPEGEncodeParam;
import com.sun.image.codec.jpeg.JPEGImageEncoder;

public class WaterMark {
     /**
      * 给图片添加水印
      * 
      * @param filePath
      *             需要添加水印的图片的路径
      * @param markContent
      *             水印的文字
      * @param markContentColor
      *             水印文字的颜色
      * @param qualNum
      *             图片质量
      * @return
      */
     public void createMark(String filePath, String markContent,
             Color markContentColor, float qualNum) {
        
         ImageIcon imgIcon = new ImageIcon(filePath);
         Image theImg = imgIcon.getImage();
         int width = theImg.getWidth(null);
         int height = theImg.getHeight(null);
         BufferedImage bimage = new BufferedImage(width, height,BufferedImage.TYPE_INT_RGB);
        
         Graphics2D g = bimage.createGraphics();
         g.setColor(markContentColor);
         g.setBackground(Color.white);
         g.drawImage(theImg, 0, 0, null);
         g.drawString(markContent, width / 3, height / 2); // 添加水印的文字和设置水印文字出现的内容
         g.dispose();
        
         try {
             FileOutputStream out = new FileOutputStream(filePath);
             JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);
             JPEGEncodeParam param = encoder.getDefaultJPEGEncodeParam(bimage);
             param.setQuality(qualNum, true);
             encoder.encode(bimage, param);
             out.close();
            
         } catch (Exception e) {
             return ;
         }
     }
    
     public static void main(String[] args) {
         WaterMark wm = new WaterMark();
        
         wm.createMark("d://map.jpg","http://www.90che.com",Color.WHITE,70f);
     }
}