生成缩小jpg图片程序

答案：import java.awt.image.BufferedImage;
import java.io.File;
import javax.swing.Icon;
import javax.swing.ImageIcon;
import javax.imageio.ImageIO;
import java.awt.image.AffineTransformOp;
import java.awt.geom.AffineTransform;
import java.awt.Image;

public class ZoomPicture{
  public static void main(String arg[]){
    
    String filePath = "g:/图片.jpg";  // 图片的位置
    
    int height=50;
    int width=150;
    Icon icon = null;
    try{
       icon = getFixedBoundIcon(filePath,height,width);
       }catch(Exception e){
        System.out.println("exception : " + e);
        }
    System.out.println(" ### " + icon);  //生成新图片的位置；
  }
  
     public static Icon getFixedBoundIcon(String filePath, int height, int width) 
        throws Exception{
        double Ratio=0.0; 
       //缩放比例 
   File F = new File(filePath); 
        if (!F.isFile()) throw new Exception
           (F+" is not image file error in getFixedBoundIcon!"); 
        Icon ret = new ImageIcon(filePath);
        BufferedImage Bi = ImageIO.read(F); 
        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(); 
    }
    int lastLength = filePath.lastIndexOf(".");
    String subFilePath = filePath.substring(0,lastLength);
    String fileType = filePath.substring(lastLength);
    File zoomFile = new File(subFilePath+"_"+height +"_"+width+fileType);
    Image Itemp = Bi.getScaledInstance (width,height,Bi.SCALE_SMOOTH);
    AffineTransformOp op = new AffineTransformOp
     (AffineTransform.getScaleInstance(Ratio, Ratio), null);
    Itemp = op.filter(Bi, null); 
    try {
      ImageIO.write((BufferedImage)Itemp, "jpg", zoomFile); 
      ret = new ImageIcon(zoomFile.getPath()); 
    }catch (Exception ex) {
     System.out.println("######## here error : " + ex);
    } 
   }
    return ret;
 }
}

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