关于java对图片及进行抽取缩略图，添加水印及水印透明度的问题

import java.io.IOException;
import java.awt.Graphics;
import java.awt.*;
import java.awt.Image;
import java.awt.image.BufferedImage;
import java.awt.image.ImageProducer;
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;
import com.sun.jimi.core.Jimi;
import com.sun.jimi.core.JimiException;
import com.sun.jimi.core.JimiWriter;
import com.sun.jimi.core.options.JPGOptions;

class ImageOperation {
public void toReduce(String source, String dest)

//将任何格式的图片转换成JPG图片

/*source原图片路径

*dest 转换后图片的路径


*/


{
      try {
       JPGOptions options = new JPGOptions();
       options.setQuality(100);
       ImageProducer image = Jimi.getImageProducer(source);// 图片格式在jimi的解码格式范围内
       JimiWriter writer = Jimi.createJimiWriter(dest);// 图片编码
       writer.setSource(image);
       writer.setOptions(options);// 对输出文件的属性进行相关的设置，每种格式的属性都不一样
       writer.putImage(dest);
      } catch (JimiException je) {
       System.err.println("Error: " + je);
      }
}
public void changDimension(String oldfile,String newfile,int wideths,int heights)throws JimiException, IOException

//实现对图片的抽取缩略并控制生成图的大小

/*

*oldfile原图片路径


*newfile缩略后的 图片路径


*wideths 缩略后图片的宽

*heights 缩略后图片的高

*/


{
      String temp = newfile;
      File inputfile = null;
      this.toReduce(oldfile, temp);
         inputfile = new File(temp); // 读入文件    
         Image src = ImageIO.read(inputfile); // 构造Image对象
         //double wideth = (double) src.getWidth(null); // 得到源图宽
         //double height = (double) src.getHeight(null); // 得到源图长
         int iWideth = wideths;
         int iHeight = heights;
         BufferedImage tag = null;  
         try{
             tag = new BufferedImage(iWideth, iHeight,BufferedImage.TYPE_INT_RGB);
          tag.getGraphics().drawImage(src, 0, 0, iWideth, iHeight, null); // 绘制缩小后的图
          JimiWriter writer = Jimi.createJimiWriter(newfile);
          writer.setSource(tag);
          writer.putImage(newfile);
         }
         catch(Exception e){
          e.printStackTrace();
         }
}
        public void Imagefont(String oldfile,String newfile,String text)

//给图片添加文字

*oldfile newfile就不用多说了


*text 就是给图片加的文字


{
         Image img;
           String filename = oldfile.substring(oldfile.lastIndexOf(".")+1);
         String temp = newfile;
    
         try{
          if(!filename.equals("jpg")){
                 this.toReduce(oldfile, newfile);
              img = ImageIO.read(new File(temp));
          }else{
              img = ImageIO.read(new File(oldfile));
          }
             int width = img.getWidth(null);  
             int height = img.getHeight(null);    
             BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);    
             Graphics g = image.createGraphics();  
          
             g.drawImage(img, 0, 0, width, height, null);    
             g.setColor(Color.red);
             g.setFont(new Font("Courier", Font.HANGING_BASELINE, 40));
             g.drawString(text, width-360, height-72);    
             g.dispose();  
        
             FileOutputStream os = new FileOutputStream(temp);    
             JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(os);    
             encoder.encode(image);
      
         }
         catch(Exception e){
          e.getMessage();
         }
        }
public void Imagese(String oldfile,String newfile,String syoldfile,int t,float to)

//给图片添加水印，并控制水印图片的位置及透明度

*oldfile newfile我也不说了

*syoldfile 要添加的水印 图片的路径


*t 水印图品添加的位置


*to 水印图片的透明度


{
         String filename = oldfile.substring(oldfile.lastIndexOf(".")+1);
         Image img;
         String temp = newfile;
         float alpha = to;
    
         try{    
          if(!filename.equals("jpg")){
                 toReduce(oldfile, newfile);
                 img = ImageIO.read(new File(temp));
             }else{
                 img = ImageIO.read(new File(oldfile));
             }
                int width = img.getWidth(null);  
                int height = img.getHeight(null);  
                int ws = width/3;
                int hs = height/3;
            
                BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);  
                Graphics2D g = image.createGraphics();    
                g.drawImage(img, 0, 0, width, height, null);    
                Image logo = ImageIO.read(new File(syoldfile));    
                int lw = logo.getWidth(null);    
                int lh = logo.getHeight(null);  
                g.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_ATOP,alpha));
          g.drawImage(logo,null,null);

                switch(t){
                    case 1:
                        g.drawImage(logo, 0, 0, lw, lh, null);
                        break;
                    case 2:
                        g.drawImage(logo, ws, 0, lw, lh, null);
                        break;
                    case 3:
                        g.drawImage(logo, 2*ws, 0, lw, lh, null);
                        break;
                    case 4:
                        g.drawImage(logo, 0, hs, lw, lh, null);
                        break;
                    case 5:
                        g.drawImage(logo, ws, hs, lw, lh, null);
                        break;
                    case 6:
                        g.drawImage(logo, 2*ws, hs, lw, lh, null);
                        break;
                    case 7:
                        g.drawImage(logo, 0, 2*hs, lw, lh, null);
                        break;
                    case 8:
                        g.drawImage(logo, ws, 2*hs, lw, lh, null);
                        break;
                    case 9:
                        g.drawImage(logo, 2*ws, 2*hs, lw, lh, null);
                        break;
                    default:
                     break;
                }    
                g.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_OVER));
                g.dispose();  
                FileOutputStream oss = new FileOutputStream(temp);    
                JPEGImageEncoder encoders = JPEGCodec.createJPEGEncoder(oss);    
                encoders.encode(image);  
         }
         catch(Exception e){
          e.getMessage();
         }
      
        }
}