如何對applet圖形存檔？？

上面的兄弟，你有JAI(java advance image interface)吗，给我一份，多谢
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为什么把APPLET 存为 a.jpeg 时打开a.jpeg什么都没有，还有我该怎么样设置时applet有权限许可才能写文件

import java.applet.Applet;
import java.awt.image.BufferedImage;
import java.io.*;
import com.sun.media.jai.codec.*;
import com.sun.media.jai.codecimpl.*;
import java.awt.*;
import java.awt.event.*;
public class HelloWorldApplet extends Applet {
  Button button1 = new Button();
  BufferedImage bi=new BufferedImage(200,100,BufferedImage.TYPE_INT_RGB);  public void paint(Graphics g) {
    Graphics bg=bi.createGraphics();   System.out.print("op");
    bg.drawString("Hello world!", 50, 25);
    g.drawImage(bi,0,0,this);
  } public static void  saveImage(BufferedImage img, File f) throws Exception{
   ImageEncoder enc = getImageEncoder(f);
      if(enc == null) {
       return; //ups...
     }
    enc.encode(img.getData(), img.getColorModel());
    enc.getOutputStream().close();
   }    public static ImageEncoder getImageEncoder(File f)
    throws Exception {         ImageEncodeParam encodeParam = null;
         String type = null;
         String name = f.getName();
         System.out.println(name);
         String ext;
         int dotIndex = name.lastIndexOf('.');
         if ( dotIndex == -1 || dotIndex == name.length()-1 ) ext = "";
         else ext = name.substring(dotIndex+1).toLowerCase();
     System.out.println(ext);
       if(ext.equals("jpeg") || ext.equals("jpg")) {
             type = "JPEG";
              encodeParam = new JPEGEncodeParam();
             ((JPEGEncodeParam)encodeParam).setQuality(1F);
        }
        else if (ext.equals("tiff") || ext.equals("tif")) {
          type = "TIFF";
          encodeParam = new TIFFEncodeParam();
          ((TIFFEncodeParam)encodeParam).setCompression(TIFFEncodeParam.COMPRESSION_NONE);
        }
        else if(ext.equals("bmp")) {
           type = "BMP";
            encodeParam = new BMPEncodeParam();
        }
        else if(ext.equals("png")) {
            type = "PNG";
           encodeParam = new PNGEncodeParam.Palette();
          ((PNGEncodeParam.Palette)encodeParam).setBitDepth(2);
        }
       else if(ext.equals("gif")) {
         System.out.println("oK");
         throw new Exception( "Gif file format is not yet supported !");
       }
       else {
           throw new Exception( "Unknown extension: " + ext);
      }
   return ImageCodec.createImageEncoder(type, new FileOutputStream(f),encodeParam);  }  public HelloWorldApplet() {
    try {
      jbInit();
    }
    catch(Exception e) {
      e.printStackTrace();
    }
  }
  private void jbInit() throws Exception {
    button1.setLabel("button1");
    button1.addActionListener(new java.awt.event.ActionListener() {
      public void actionPerformed(ActionEvent e) {
        button1_actionPerformed(e);
      }
    });
    this.add(button1, null);
  }  void button1_actionPerformed(ActionEvent e) {
   String s="classes/a.jpeg";
   File f=new File(s);
   HelloWorldApplet hwa=new HelloWorldApplet();
   System.out.print(s);
  try
  {
    hwa.saveImage(bi, f);
  }
  catch(Exception ee){
    System.out.println(e.toString());}
}}

/*
* @(#)GIFEncoder.java 0.90 4/21/96 Adam Doppelt
*/package GIFEncoder;import java.io.*;
import java.awt.*;
import java.awt.image.*;/** * GIFEncoder is a class which takes an image and saves it to a stream * using the GIF file format (<A * HREF="http://www.dcs.ed.ac.uk/%7Emxr/gfx/">Graphics Interchange * Format</A>). A GIFEncoder * is constructed with either an AWT Image (which must be fully * loaded) or a set of RGB arrays. The image can be written out with a * call to <CODE>Write</CODE>. * * Three caveats: * <UL> * <LI>GIFEncoder will convert the image to indexed color upon * construction. This will take some time, depending on the size of * the image. Also, actually writing the image out (Write) will take * time. * * <LI>The image cannot have more than 256 colors, since GIF is an 8 * bit format. For a 24 bit to 8 bit quantization algorithm, see * Graphics Gems II III.2 by Xialoin Wu. Or check out his <A * HREF="http://www.csd.uwo.ca/faculty/wu/cq.c">C source</A>. * * <LI>Since the image must be completely loaded into memory, * GIFEncoder may have problems with large images. Attempting to * encode an image which will not fit into memory will probably * result in the following exception: * <CODE>java.awt.AWTException: Grabber returned false: 192</CODE> * </UL> * * GIFEncoder is based upon gifsave.c, which was written and released * by: * <CENTER> * Sverre H. Huseby * Bjoelsengt. 17 * N-0468 Oslo * Norway * * Phone: +47 2 230539 * [email protected] * </CENTER> * @version 0.90 21 Apr 1996 * @author <A HREF="http://www.cs.brown.edu/people/amd/">Adam Doppelt</A> */public class GIFEncoder
{
 short width_, height_;
 int numColors_;
 byte pixels_[], colors_[];
 ScreenDescriptor sd_;
 ImageDescriptor id_;
 /**
 * Construct a GIFEncoder. The constructor will convert the image to
 * an indexed color array. This may take some time.
 *
 * @param image The image to encode. The image must be
 * completely loaded.
 * @exception AWTException Will be thrown if the pixel grab fails. This
 * can happen if Java runs out of memory. It may also indicate that the image
 * contains more than 256 colors.
 * */
 public GIFEncoder (Image image) throws AWTException
 {
 width_ = (short)image.getWidth(null);
 height_ = (short)image.getHeight(null);
 int values[] = new int[width_ * height_];
 PixelGrabber grabber = new PixelGrabber(image, 0, 0, width_, height_, values, 0, width_);
 try
 {
 if(grabber.grabPixels() != true)
 throw new AWTException("Grabber returned false: " + grabber.status());
 }
 catch(InterruptedException e)
 {
 }
 byte r[][] = new byte[width_][height_];
 byte g[][] = new byte[width_][height_];
 byte b[][] = new byte[width_][height_];
 int index = 0;
 for(int y = 0; y < height_; ++y)
 for(int x = 0; x < width_; ++x)
 {
 r[x][y] = (byte)((values[index] >> 16) & 0xFF);
 g[x][y] = (byte)((values[index] >> 8) & 0xFF);
 b[x][y] = (byte)((values[index]) & 0xFF);
 ++index;
 }
 ToIndexedColor(r, g, b);
 }
 /**
 * Construct a GIFEncoder. The constructor will convert the image to
 * an indexed color array. This may take some time.
 *
 * Each array stores intensity values for the image. In other words,
 * r[x][y] refers to the red intensity of the pixel at column x, row
 * y.
 *
 * @param r An array containing the red intensity values.
 * @param g An array containing the green intensity values.
 * @param b An array containing the blue intensity values.
 *
 * @exception AWTException Will be thrown if the image contains more than
 * 256 colors.
 * */
 public GIFEncoder (byte r[][], byte g[][], byte b[][]) throws AWTException
 {
 width_ = (short)(r.length);
 height_ = (short)(r[0].length);
 ToIndexedColor(r, g, b);
 }
 /**
 * Writes the image out to a stream in the GIF file format. This will
 * be a single GIF87a image, non-interlaced, with no background color.
 * This may take some time.
 *
 * @param output The stream to output to. This should probably be a
 * buffered stream.
 *
 * @exception IOException Will be thrown if a write operation fails.
 * */
 public void Write(OutputStream output) throws IOException
 {
 BitUtils.WriteString(output, "GIF87a");
 ScreenDescriptor sd = new ScreenDescriptor(width_, height_, numColors_);
 sd.Write(output);
 output.write(colors_, 0, colors_.length);
 ImageDescriptor id = new ImageDescriptor(width_, height_, ',');
 id.Write(output);
 byte codesize = BitUtils.BitsNeeded(numColors_);
 if(codesize == 1)
 ++codesize;
 output.write(codesize);
 LZWCompressor.LZWCompress(output, codesize, pixels_);
 output.write(0);
 id = new ImageDescriptor((byte)0, (byte)0, ';');
 id.Write(output);
 output.flush();
 }
 void ToIndexedColor(byte r[][], byte g[][], byte b[][]) throws AWTException
 {
 pixels_ = new byte[width_ * height_];
 colors_ = new byte[256 * 3];
 int colornum = 0;
 for(int x = 0; x < width_; ++x)
 {
 for(int y = 0; y < height_; ++y)
 {
 int search;
 for(search = 0; search < colornum; ++search)
 if(colors_[search * 3] == r[x][y] && colors_[search * 3 + 1] == g[x][y] && colors_[search * 3 + 2] == b[x][y])
 break;
 if(search > 255)
 throw new AWTException("Too many colors.");
 pixels_[y * width_ + x] = (byte)search;
 if(search == colornum)
 {
 colors_[search * 3] = r[x][y];
 colors_[search * 3 + 1] = g[x][y];
 colors_[search * 3 + 2] = b[x][y];
 ++colornum;
 }
 }
 }
 numColors_ = 1 << BitUtils.BitsNeeded(colornum);
 byte copy[] = new byte[numColors_ * 3];
 System.arraycopy(colors_, 0, copy, 0, numColors_ * 3);
 colors_ = copy;
 }
}class BitFile
{
 OutputStream output_;
 byte buffer_[];
 int index_, bitsLeft_;
 public BitFile (OutputStream output)
 {
 output_ = output;
 buffer_ = new byte[256];
 index_ = 0;
 bitsLeft_ = 8;
 }
 public void Flush() throws IOException
 {
 int numBytes = index_ + (bitsLeft_ == 8 ? 0 : 1);
 if(numBytes > 0)
 {
 output_.write(numBytes);
 output_.write(buffer_, 0, numBytes);
 buffer_[0] = 0;
 index_ = 0;
 bitsLeft_ = 8;
 }
 }
 public void WriteBits(int bits, int numbits) throws IOException
 {
 int bitsWritten = 0;
 int numBytes = 255;
 do
 {
 if((index_ == 254 && bitsLeft_ == 0) || index_ > 254)
 {
 output_.write(numBytes);
 output_.write(buffer_, 0, numBytes);
 buffer_[0] = 0;
 index_ = 0;
 bitsLeft_ = 8;
 }
 if(numbits <= bitsLeft_)
 {
 buffer_[index_] |= (bits & ((1 << numbits) - 1)) << (8 - bitsLeft_);
 bitsWritten += numbits;
 bitsLeft_ -= numbits;
 numbits = 0;
 }
 else
 {
 buffer_[index_] |= (bits & ((1 << bitsLeft_) - 1)) << (8 - bitsLeft_);
 bitsWritten += bitsLeft_;
 bits >>= bitsLeft_;
 numbits -= bitsLeft_;
 buffer_[++index_] = 0;
 bitsLeft_ = 8;
 }
 }while(numbits != 0);
 }
}class LZWStringTable
{
 private final static int RES_CODES = 2;
 private final static short HASH_FREE = (short)0xFFFF;
 private final static short NEXT_FIRST = (short)0xFFFF;
 private final static int MAXBITS = 12;
 private final static int MAXSTR = (1 << MAXBITS);
 private final static short HASHSIZE = 9973;
 private final static short HASHSTEP = 2039;
 byte strChr_[];
 short strNxt_[];
 short strHsh_[];
 short numStrings_;
 public LZWStringTable ()
 {
 strChr_ = new byte[MAXSTR];
 strNxt_ = new short[MAXSTR];
 strHsh_ = new short[HASHSIZE];
 }
 public int AddCharString(short index, byte b)
 {
 int hshidx;
 if(numStrings_ >= MAXSTR)
 return 0xFFFF;
 hshidx = Hash(index, b);
 while(strHsh_[hshidx] != HASH_FREE)
 hshidx = (hshidx + HASHSTEP) % HASHSIZE;
 strHsh_[hshidx] = numStrings_;
 strChr_[numStrings_] = b;
 strNxt_[numStrings_] = (index != HASH_FREE) ? index : NEXT_FIRST;
 return numStrings_++;
 }
 public short FindCharString(short index, byte b)
 {
 int hshidx, nxtidx;
 if(index == HASH_FREE)
 return b;
 hshidx = Hash(index, b);
 while((nxtidx = strHsh_[hshidx]) != HASH_FREE)
 {
 if(strNxt_[nxtidx] == index && strChr_[nxtidx] == b)
 return (short)nxtidx;
 hshidx = (hshidx + HASHSTEP) % HASHSIZE;
 }
 return (short)0xFFFF;
 }
 public void ClearTable(int codesize)
 {
 numStrings_ = 0;
 for(int q = 0; q < HASHSIZE; q ++ )
 {
 strHsh_[q] = HASH_FREE;
 }
 int w = (1 << codesize) + RES_CODES;
 for(int q = 0; q < w; q ++ )
 AddCharString((short)0xFFFF, (byte)q);
 }
 static public int Hash(short index, byte lastbyte)
 {
 return ((int)((short)(lastbyte << 8) ^ index) & 0xFFFF) % HASHSIZE;
 }
}class LZWCompressor
{
 public static void LZWCompress(OutputStream output, int codesize, byte toCompress[]) throws IOException
 {
 byte c;
 short index;
 int clearcode, endofinfo, numbits, limit, errcode;
 short prefix = (short)0xFFFF;
 BitFile bitFile = new BitFile(output);
 LZWStringTable strings = new LZWStringTable();
 clearcode = 1 << codesize;
 endofinfo = clearcode + 1;
 numbits = codesize + 1;
 limit = (1 << numbits) - 1;
 strings.ClearTable(codesize);
 bitFile.WriteBits(clearcode, numbits);
 for(int loop = 0; loop < toCompress.length; ++loop)
 {
 c = toCompress[loop];
 if((index = strings.FindCharString(prefix, c)) != -1)
 prefix = index;
 else
 {
 bitFile.WriteBits(prefix, numbits);
 if(strings.AddCharString(prefix, c) > limit)
 {
 if(++numbits > 12)
 {
 bitFile.WriteBits(clearcode, numbits - 1);
 strings.ClearTable(codesize);
 numbits = codesize + 1;
 }
 limit = (1 << numbits) - 1;
 }
 prefix = (short)((short)c & 0xFF);
 }
 }
 if(prefix != -1)
 bitFile.WriteBits(prefix, numbits);
 bitFile.WriteBits(endofinfo, numbits);
 bitFile.Flush();
 }
}class ScreenDescriptor
{
 public short localScreenWidth_, localScreenHeight_;
 private byte byte_;
 public byte backgroundColorIndex_, pixelAspectRatio_;
 public ScreenDescriptor (short width, short height, int numColors)
 {
 localScreenWidth_ = width;
 localScreenHeight_ = height;
 SetGlobalColorTableSize((byte)(BitUtils.BitsNeeded(numColors) - 1));
 SetGlobalColorTableFlag((byte)1);
 SetSortFlag((byte)0);
 SetColorResolution((byte)7);
 backgroundColorIndex_ = 0;
 pixelAspectRatio_ = 0;
 }
 public void Write(OutputStream output) throws IOException
 {
 BitUtils.WriteWord(output, localScreenWidth_);
 BitUtils.WriteWord(output, localScreenHeight_);
 output.write(byte_);
 output.write(backgroundColorIndex_);
 output.write(pixelAspectRatio_);
 }
 public void SetGlobalColorTableSize(byte num)
 {
 byte_ |= (num & 7);
 }
 public void SetSortFlag(byte num)
 {
 byte_ |= (num & 1) << 3;
 }
 public void SetColorResolution(byte num)
 {
 byte_ |= (num & 7) << 4;
 }
 public void SetGlobalColorTableFlag(byte num)
 {
 byte_ |= (num & 1) << 7;
 }
}class ImageDescriptor
{
 public byte separator_;
 public short leftPosition_, topPosition_, width_, height_;
 private byte byte_;
 public ImageDescriptor (short width, short height, char separator)
 {
 separator_ = (byte)separator;
 leftPosition_ = 0;
 topPosition_ = 0;
 width_ = width;
 height_ = height;
 SetLocalColorTableSize((byte)0);
 SetReserved((byte)0);
 SetSortFlag((byte)0);
 SetInterlaceFlag((byte)0);
 SetLocalColorTableFlag((byte)0);
 }
 public void Write(OutputStream output) throws IOException
 {
 output.write(separator_);
 BitUtils.WriteWord(output, leftPosition_);
 BitUtils.WriteWord(output, topPosition_);
 BitUtils.WriteWord(output, width_);
 BitUtils.WriteWord(output, height_);
 output.write(byte_);
 }
 public void SetLocalColorTableSize(byte num)
 {
 byte_ |= (num & 7);
 }
 public void SetReserved(byte num)
 {
 byte_ |= (num & 3) << 3;
 }
 public void SetSortFlag(byte num)
 {
 byte_ |= (num & 1) << 5;
 }
 public void SetInterlaceFlag(byte num)
 {
 byte_ |= (num & 1) << 6;
 }
 public void SetLocalColorTableFlag(byte num)
 {
 byte_ |= (num & 1) << 7;
 }
}class BitUtils
{
 public static byte BitsNeeded(int n)
 {
 byte ret = 1;
 if(n-- == 0)
 return 0;
 while((n >>= 1) != 0)
 ++ret;
 return ret;
 }
 public static void WriteWord(OutputStream output, short w) throws IOException
 {
 output.write(w & 0xFF);
 output.write((w >> 8) & 0xFF);
 }
 static void WriteString(OutputStream output, String string) throws IOException
 {
 for(int loop = 0; loop < string.length(); ++loop)
 output.write((byte)(string.charAt(loop)));
 }
}

看不懂，我想实现applet画的图形存为gif该怎么做？

调试易

如何對applet圖形存檔？？

解决方案 »