java图片压缩

package com.sun.jsonutil; 

import java.awt.Color; 
import java.awt.Component; 
import java.awt.Graphics; 
import java.awt.Graphics2D; 
import java.awt.Image; 
import java.awt.MediaTracker; 
import java.awt.Toolkit; 
import java.awt.image.BufferedImage; 
import java.awt.image.ConvolveOp; 
import java.awt.image.Kernel; 
import java.io.ByteArrayOutputStream; 
import java.io.File; 
import java.io.FileInputStream; 
import java.io.FileOutputStream; 
import java.io.IOException; 
import java.io.OutputStream; 

import javax.imageio.ImageIO; 
import javax.swing.ImageIcon; 

import com.sun.image.codec.jpeg.JPEGCodec; 
import com.sun.image.codec.jpeg.JPEGEncodeParam; 
import com.sun.image.codec.jpeg.JPEGImageEncoder; 

/** 
* 图像压缩工具 
* @author come from net 
* 
*/ 
public class ImageSizer { 
    public static final MediaTracker tracker = new MediaTracker(new Component() { 
        private static final long serialVersionUID = 1234162663955668507L;} 
    ); 
    /** 
     * @param originalFile 原图像 
     * @param resizedFile 压缩后的图像 
     * @param width 图像宽 
     * @param format 图片格式 jpg, png, gif(非动画) 
     * @throws IOException 
     */ 
    public static void resize(File originalFile, File resizedFile, int width, String format) throws IOException { 
        if(format!=null && "gif".equals(format.toLowerCase())){ 
        resize(originalFile, resizedFile, width, 1); 
        return; 
        } 
        FileInputStream fis = new FileInputStream(originalFile); 
        ByteArrayOutputStream byteStream = new ByteArrayOutputStream(); 
        int readLength = -1; 
        int bufferSize = 1024; 
        byte bytes[] = new byte[bufferSize]; 
        while ((readLength = fis.read(bytes, 0, bufferSize)) != -1) { 
            byteStream.write(bytes, 0, readLength); 
        } 
        byte[] in = byteStream.toByteArray(); 
        fis.close(); 
        byteStream.close(); 
        
    Image inputImage = Toolkit.getDefaultToolkit().createImage( in ); 
        waitForImage( inputImage ); 
        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" ); 
        
        // Create output image. 
        int height = -1; 
        double scaleW = (double) imageWidth / (double) width; 
        double scaleY = (double) imageHeight / (double) height; 
        if (scaleW >= 0 && scaleY >=0) { 
            if (scaleW > scaleY) { 
                height = -1; 
            } else { 
                width = -1; 
            } 
        } 
        Image outputImage = inputImage.getScaledInstance( width, height, java.awt.Image.SCALE_DEFAULT); 
        checkImage( outputImage );        
        encode(new FileOutputStream(resizedFile), outputImage, format);        
    }    

    /** Checks the given image for valid width and height. */ 
    private static 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" ); 
    } 

    /** Waits for given image to load. Use before querying image height/width/colors. */ 
    private static void waitForImage( Image image ) { 
       try { 
          tracker.addImage( image, 0 ); 
          tracker.waitForID( 0 ); 
          tracker.removeImage(image, 0); 
       } catch( InterruptedException e ) { e.printStackTrace(); } 
    } 

    /** Encodes the given image at the given quality to the output stream. */ 
    private static void encode( OutputStream outputStream, Image outputImage, String format ) 
       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 ); 
       ImageIO.write(bi, format, outputStream); 
       outputStream.flush();      
    } 
    

/** 
* 缩放gif图片 
* @param originalFile 原图片 
* @param resizedFile 缩放后的图片 
* @param newWidth 宽度 
* @param quality 缩放比例 (等比例) 
* @throws IOException 
*/ 
    private static void resize(File originalFile, File resizedFile, int newWidth, float quality) throws IOException { 
        if (quality < 0 || quality > 1) { 
            throw new IllegalArgumentException("Quality has to be between 0 and 1"); 
        } 
        ImageIcon ii = new ImageIcon(originalFile.getCanonicalPath()); 
        Image i = ii.getImage(); 
        Image resizedImage = null; 
        int iWidth = i.getWidth(null); 
        int iHeight = i.getHeight(null); 
        if (iWidth > iHeight) { 
            resizedImage = i.getScaledInstance(newWidth, (newWidth * iHeight) / iWidth, Image.SCALE_SMOOTH); 
        } else { 
            resizedImage = i.getScaledInstance((newWidth * iWidth) / iHeight, newWidth, Image.SCALE_SMOOTH); 
        } 
        // This code ensures that all the pixels in the image are loaded. 
        Image temp = new ImageIcon(resizedImage).getImage(); 
        // Create the buffered image. 
        BufferedImage bufferedImage = new BufferedImage(temp.getWidth(null), temp.getHeight(null), 
                                                        BufferedImage.TYPE_INT_RGB); 
        // Copy image to buffered image. 
        Graphics g = bufferedImage.createGraphics(); 
        // Clear background and paint the image. 
        g.setColor(Color.white); 
        g.fillRect(0, 0, temp.getWidth(null), temp.getHeight(null)); 
        g.drawImage(temp, 0, 0, null); 
        g.dispose(); 
        // Soften. 
        float softenFactor = 0.05f; 
        float[] softenArray = {0, softenFactor, 0, softenFactor, 1-(softenFactor*4), softenFactor, 0, softenFactor, 0}; 
        Kernel kernel = new Kernel(3, 3, softenArray); 
        ConvolveOp cOp = new ConvolveOp(kernel, ConvolveOp.EDGE_NO_OP, null); 
        bufferedImage = cOp.filter(bufferedImage, null); 
        // Write the jpeg to a file. 
        FileOutputStream out = new FileOutputStream(resizedFile);        
        // Encodes image as a JPEG data stream 
        JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out); 
        JPEGEncodeParam param = encoder.getDefaultJPEGEncodeParam(bufferedImage); 
        param.setQuality(quality, true); 
        encoder.setJPEGEncodeParam(param); 
        encoder.encode(bufferedImage); 
    } 
}