JPEG encoder quality problem

Question

my static method is as follow: (copy from here, and i and a setQuality Method)
public class JPEGHandler
     public static void saveJPG(BufferedImage bi,float q,String pathname){
          String s = null;
          //BufferedImage bi = createBufferedImage(img);
          FileOutputStream out = null;
          try     {
               File file = new File(pathname);
               s = file.getName();
               out = new FileOutputStream(file);
          catch (java.io.FileNotFoundException io){
               System.out.println("File Not Found");
          catch (java.io.IOException e){
               System.err.println(e);
               JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);
               JPEGEncodeParam param = encoder.getDefaultJPEGEncodeParam(bi);
               param.setQuality(q, true); //Set the quality
          try {
               encoder.encode(bi);
          catch (java.io.IOException io)
               System.out.println("IOException");
          try{
               out.close();
          catch (java.io.IOException io){
               System.out.println("IOException");
          System.out.println("JPEG Saved: " + s);
no matter i assign 0.5 or 1 to the setQuality method, the quailty and the file size of the jpg remain unchange.
also, i have tried to set the second param of setQuailty to true and false, it dosn't help at all !!
Anyone know how to solve it ?

Answer 1

try{
     ByteArrayInputStream in=new ByteArrayInputStream(image_data);
     JPEGImageDecoder decoder =JPEGCodec.createJPEGDecoder(in,params);
     image = decoder.decodeAsBufferedImage();
     in.close();
     }catch (Exception e) {
     System.err.println("Exception "+e + " decoding "+image_name+" as JPEG");
I've just been playing with Java 1.4 (which includes updates Graphics2D) and it fixes a number or errors I had with 1.3
MArk