用java实现print screen,读取位图文件,将位图文件转化位jpeg格式并保存成文件输出!

类别:Java 点击:0 评论:0 推荐:

package screensaver;

import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.*;
import java.util.*;
import com.sun.image.codec.jpeg.*;
import java.awt.Image;
import java.awt.Toolkit;
import java.awt.image.BufferedImage;
import java.awt.image.MemoryImageSource;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import com.sun.image.codec.jpeg.JPEGCodec;
import com.sun.image.codec.jpeg.JPEGImageEncoder;

public class ScreenPicSaver
{
  MediaTracker tracker = new MediaTracker(new Component()
  {});

  public ScreenPicSaver()
  {}

  public Image loadbitmap(String sdir, String sfile) //读取8位或24位的位图文件
  {
    Image image;
    System.out.println("loading:" + sdir + sfile);
    try
    {
      FileInputStream fs = new FileInputStream(sdir + sfile);
      int bflen = 14; // 14 字节 BITMAPFILEHEADER
      byte bf[] = new byte[bflen];
      fs.read(bf, 0, bflen);
      int bilen = 40; // 40 字节 BITMAPINFOHEADER
      byte bi[] = new byte[bilen];
      fs.read(bi, 0, bilen);

      // 解释数据。
      int nsize = ( ( (int) bf[5] & 0xff) << 24)
          | ( ( (int) bf[4] & 0xff) << 16)
          | ( ( (int) bf[3] & 0xff) << 8)
          | (int) bf[2] & 0xff;
      System.out.println("File type is :" + (char) bf[0] + (char) bf[1]);
      System.out.println("Size of file is :" + nsize);

      int nbisize = ( ( (int) bi[3] & 0xff) << 24)
          | ( ( (int) bi[2] & 0xff) << 16)
          | ( ( (int) bi[1] & 0xff) << 8)
          | (int) bi[0] & 0xff;
      System.out.println("Size of bitmapinfoheader is :" + nbisize);

      int nwidth = ( ( (int) bi[7] & 0xff) << 24)
          | ( ( (int) bi[6] & 0xff) << 16)
          | ( ( (int) bi[5] & 0xff) << 8)
          | (int) bi[4] & 0xff;
      System.out.println("Width is :" + nwidth);

      int nheight = ( ( (int) bi[11] & 0xff) << 24)
          | ( ( (int) bi[10] & 0xff) << 16)
          | ( ( (int) bi[9] & 0xff) << 8)
          | (int) bi[8] & 0xff;
      System.out.println("Height is :" + nheight);

      int nplanes = ( ( (int) bi[13] & 0xff) << 8) | (int) bi[12] & 0xff;
      System.out.println("Planes is :" + nplanes);

      int nbitcount = ( ( (int) bi[15] & 0xff) << 8) | (int) bi[14] & 0xff;
      System.out.println("BitCount is :" + nbitcount);

      // 查找表明压缩的非零值
      int ncompression = ( ( (int) bi[19]) << 24)
          | ( ( (int) bi[18]) << 16)
          | ( ( (int) bi[17]) << 8)
          | (int) bi[16];
      System.out.println("Compression is :" + ncompression);

      int nsizeimage = ( ( (int) bi[23] & 0xff) << 24)
          | ( ( (int) bi[22] & 0xff) << 16)
          | ( ( (int) bi[21] & 0xff) << 8)
          | (int) bi[20] & 0xff;
      System.out.println("SizeImage is :" + nsizeimage);

      int nxpm = ( ( (int) bi[27] & 0xff) << 24)
          | ( ( (int) bi[26] & 0xff) << 16)
          | ( ( (int) bi[25] & 0xff) << 8)
          | (int) bi[24] & 0xff;
      System.out.println("X-Pixels per meter is :" + nxpm);

      int nypm = ( ( (int) bi[31] & 0xff) << 24)
          | ( ( (int) bi[30] & 0xff) << 16)
          | ( ( (int) bi[29] & 0xff) << 8)
          | (int) bi[28] & 0xff;
      System.out.println("Y-Pixels per meter is :" + nypm);

      int nclrused = ( ( (int) bi[35] & 0xff) << 24)
          | ( ( (int) bi[34] & 0xff) << 16)
          | ( ( (int) bi[33] & 0xff) << 8)
          | (int) bi[32] & 0xff;
      System.out.println("Colors used are :" + nclrused);

      int nclrimp = ( ( (int) bi[39] & 0xff) << 24)
          | ( ( (int) bi[38] & 0xff) << 16)
          | ( ( (int) bi[37] & 0xff) << 8)
          | (int) bi[36] & 0xff;
      System.out.println("Colors important are :" + nclrimp);

      if (nbitcount == 24)
      {
        // 24 位格式不包含调色板数据,但扫描行被补足到
        // 4 个字节。
        int npad = (nsizeimage / nheight) - nwidth * 3;
        int ndata[] = new int[nheight * nwidth];
        byte brgb[] = new byte[ (nwidth + npad) * 3 * nheight];
        fs.read(brgb, 0, (nwidth + npad) * 3 * nheight);
        int nindex = 0;
        for (int j = 0; j < nheight; j++)
        {
          for (int i = 0; i < nwidth; i++)
          {
            ndata[nwidth * (nheight - j - 1) + i] =
                (255 & 0xff) << 24
                | ( ( (int) brgb[nindex + 2] & 0xff) << 16)
                | ( ( (int) brgb[nindex + 1] & 0xff) << 8)
                | (int) brgb[nindex] & 0xff;
            /**   System.out.println("Encoded Color at ("
               +i + "," + j + ")is:" + nrgb + " (R,G,B)= ("
                   + ( (int) (brgb[2]) & 0xff) + ","
                   + ( (int) brgb[1] & 0xff) + ","
                   + ( (int) brgb[0] & 0xff) + ")");
             }*/
            nindex += 3;
          }
          nindex += npad;
        }

        image = Toolkit.getDefaultToolkit().createImage
            (new MemoryImageSource(nwidth, nheight,
                                   ndata, 0, nwidth));
      }
      else if (nbitcount == 8)
      {
        // 必须确定颜色数。如果 clrsused 参数大于 0,
        // 则颜色数由它决定。如果它等于 0,则根据
        // bitsperpixel 计算颜色数。
        int nNumColors = 0;
        if (nclrused > 0)
        {
          nNumColors = nclrused;
        }
        else
        {
          nNumColors = (1 & 0xff) << nbitcount;
        }
        System.out.println("The number of Colors is" + nNumColors);

        // 某些位图不计算 sizeimage 域,请找出
        // 这些情况并对它们进行修正。
        if (nsizeimage == 0)
        {
          nsizeimage = ( ( ( (nwidth * nbitcount) + 31) & ~31) >> 3);
          nsizeimage *= nheight;
          System.out.println("nsizeimage (backup) is" + nsizeimage);
        }

        // 读取调色板颜色。
        int npalette[] = new int[nNumColors];
        byte bpalette[] = new byte[nNumColors * 4];
        fs.read(bpalette, 0, nNumColors * 4);
        int nindex8 = 0;
        for (int n = 0; n < nNumColors; n++)
        {
          npalette[n] = (255 & 0xff) << 24
              | ( ( (int) bpalette[nindex8 + 2] & 0xff) << 16)
              | ( ( (int) bpalette[nindex8 + 1] & 0xff) << 8)
              | (int) bpalette[nindex8] & 0xff;
          /**System.out.println ("Palette Color "+n
                     +" is:" + npalette[n] + " (res,R,G,B)= ("
              + ( (int) (bpalette[nindex8 + 3]) & 0xff) + ","
              + ( (int) (bpalette[nindex8 + 2]) & 0xff) + ","
              + ( (int) bpalette[nindex8 + 1] & 0xff) + ","
              + ( (int) bpalette[nindex8] & 0xff) + ")");
           */
          nindex8 += 4;
        }

        // 读取图像数据(实际上是调色板的索引)
        // 扫描行仍被补足到 4 个字节。
        int npad8 = (nsizeimage / nheight) - nwidth;
        System.out.println("nPad is:" + npad8);

        int ndata8[] = new int[nwidth * nheight];
        byte bdata[] = new byte[ (nwidth + npad8) * nheight];
        fs.read(bdata, 0, (nwidth + npad8) * nheight);
        nindex8 = 0;
        for (int j8 = 0; j8 < nheight; j8++)
        {
          for (int i8 = 0; i8 < nwidth; i8++)
          {
            ndata8[nwidth * (nheight - j8 - 1) + i8] =
                npalette[ ( (int) bdata[nindex8] & 0xff)];
            nindex8++;
          }
          nindex8 += npad8;
        }

        image = Toolkit.getDefaultToolkit().createImage
            (new MemoryImageSource(nwidth, nheight,
                                   ndata8, 0, nwidth));
      }
      else
      {
        System.out.println("Not a 24-bit or 8-bit Windows Bitmap, aborting...");
        image = (Image)null;
      }

      fs.close();
      return image;
    }
    catch (Exception e)
    {
      System.out.println("Caught exception in loadbitmap!");
    }
    return (Image)null;
  }

  public void waitForImage(Image image)
  {
    //tracker = new MediaTracker(this);
    try
    {
      tracker.addImage(image, 0); //public void addImage(Image image,int id)
      //tracker.waitForAll();
      tracker.waitForID(0);
      tracker.checkAll(true);
      /** while(!tracker.checkID(0))
       {
         tracker.waitForID(0);
       }*/
      if (tracker.isErrorAny())
      {
        // System.out.println(tracker.getErrorsAny().toString());
        System.out.println("加载图像出现错误!");
        System.exit(0);
      }

      // loadStatus = tracker.statusID( 0, false );
      // tracker.removeImage(image, 0);
    }
    catch (InterruptedException e)
    {
      e.printStackTrace();
    }
  } // waitForImage

  public void checkImage(Image image)
  {
    waitForImage(image);

    int imageWidth = image.getWidth(null);
    if (imageWidth < 1)
    {
      throw new IllegalArgumentException("image width " + imageWidth +
                                         " is out of range");
    }
    int imageHeight = image.getHeight(null);
    if (imageHeight < 1)
    {
      throw new IllegalArgumentException("image height " + imageHeight +
                                         " is out of range");
    }
    // System.out.println( "Image size=" + imageWidth + "x" + imageHeight );
  } // checkImage

  public void encodeJPEG(OutputStream outputStream, Image outputImage,
                         float outputQuality) throws java.io.IOException
  {
    int outputWidth = outputImage.getWidth(null);
    if (outputWidth < 1)
    {
      throw new IllegalArgumentException("output image width " + outputWidth +
                                         " is out of range");
    }
    int outputHeight = outputImage.getHeight(null);
    if (outputHeight < 1)
    {
      throw new IllegalArgumentException("output image height " + outputHeight +
                                         " is out of range");
    }

    // Get a buffered image from the image.
    BufferedImage bi = new BufferedImage(outputWidth, outputHeight,
                                         BufferedImage.TYPE_INT_RGB);
    Graphics2D biContext = bi.createGraphics();
    biContext.drawImage(outputImage, 0, 0, null);
    // Note that additional drawing such as watermarks or logos can be placed here.

    // com.sun.image.codec.jpeg package is included in sun and ibm sdk 1.3
    JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(outputStream);
    // The default quality is 0.75.
    JPEGEncodeParam jep = JPEGCodec.getDefaultJPEGEncodeParam(bi);
    jep.setQuality(outputQuality, true);
    encoder.encode(bi, jep);
    // encoder.encode( bi );
    outputStream.flush();
  } // encodeImage

  /** Adjusts the size of the image to the given coordinates.
   * If width or height is -1, the image aspect ration is maintained.
   * <p>
   * Hints are one of SCALE_DEFAULT, SCALE_FAST, SCALE_SMOOTH,
   * SCALE_REPLICATE, SCALE_AREA_AVERAGING as defined in java.awt.Image.
   */
  public Image setSize(Image image, int width, int height, int hints)
  {
    return image.getScaledInstance(width, height, hints);
  } // setSize

  public Image setSize(Image image, int width, int height)
  {
    return setSize(image, width, height, java.awt.Image.SCALE_DEFAULT); //setSize调用的是上一个方法.
  } // setSize

  //Component initialization
  public static void main(String[] args)
  {
    ScreenPicSaver sps = new ScreenPicSaver();
    // String sdir = new String("d:\\");
    // String sfile = new String("desktop.bmp");
    String outputFileName = new String("d:\\desktop.jpg");

    //Image inputImage = Toolkit.getDefaultToolkit().getImage(inputFileName);
    //Image inputImage = sps.loadbitmap(sdir, sfile);
    //===============================================================
    BufferedImage bufferedImage = null;
    Robot robot;
    Image inputImage = null;
    try
    {
      robot = new Robot();
      bufferedImage = robot.createScreenCapture(new Rectangle(Toolkit.
          getDefaultToolkit().getScreenSize())); //得到桌面图像的bufferedImage对象

    }
    catch (Exception ex)
    {
      ex.printStackTrace();
    }
    int width = bufferedImage.getWidth();
    int height = bufferedImage.getHeight();
    inputImage = bufferedImage.getScaledInstance(width, height,
                                                 BufferedImage.TYPE_INT_RGB); //将bufferedImage对象转化位Image对象

    MediaTracker tracker = new MediaTracker(new Component()
    {});

    int outputWidth = inputImage.getWidth(null); //使得新图像和原图像的宽度一样
    float outputQuality = 0.80f;
    Image outputImage = sps.setSize(inputImage, outputWidth, -1); //-1表示在宽度确定的情况下,高度在原图像的基础上成比例缩放

    try
    {
      tracker.addImage(inputImage, 0);
      //sps.tracker.waitForAll();
      tracker.waitForID(0);
      tracker.checkAll(true);
    }
    catch (InterruptedException e)
    {
      e.printStackTrace();
    }

    int imageWidth = inputImage.getWidth(null);
    if (imageWidth < 1)
    {
      throw new IllegalArgumentException("image width " + imageWidth +
                                         " is out of range");
    }
    int imageHeight = inputImage.getHeight(null);
    if (imageHeight < 1)
    {
      throw new IllegalArgumentException("image height " + imageHeight +
                                         " is out of range");
    }
    try
    {
      FileOutputStream fos = new FileOutputStream(outputFileName);
      sps.encodeJPEG(fos, outputImage, outputQuality);
      fos.flush();
      fos.close();
    }
    catch (Exception e)
    {
      e.printStackTrace();
    }

    System.exit(0);

  }

}

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