Java上传图片后的缩放

import java.awt.Color;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.image.BufferedImage;
import java.awt.image.ConvolveOp;
import java.awt.image.Kernel;
import java.io.File;
import java.io.FileOutputStream;
import java.io.InputStream;
 
import org.apache.commons.fileupload.FileItem;
import org.apache.log4j.Logger;
 
import com.sun.image.codec.jpeg.JPEGCodec;
import com.sun.image.codec.jpeg.JPEGImageEncoder;
 
public class ImageUtil {
    /**
     * Logger for this class
     */
    private static final Logger logger = Logger.getLogger(ImageUtil.class);
 
    public void imageScale(String srcFilePath,String targetFilePath,int width,int height) {
        this.imageScale(new File(srcFilePath),new File(targetFilePath),width,height);
    }
 
    public void imageScale(File srcFile,File targetFile,int height) {
        try {
            Image image = javax.imageio.ImageIO.read(srcFile);
 
            image = image.getScaledInstance(width,height,Image.SCALE_AREA_AVERAGING);
            // Make a BufferedImage from the Image.
            BufferedImage mBufferedImage = new BufferedImage(width,BufferedImage.TYPE_INT_RGB);
            Graphics2D g2 = mBufferedImage.createGraphics();            
 
            g2.drawImage(image,Color.white,null);
            g2.dispose();
 
            float[] kernelData2 = { -0.125f,-0.125f,2,-0.125f };
            Kernel kernel = new Kernel(3,3,kernelData2);
            ConvolveOp cOp = new ConvolveOp(kernel,ConvolveOp.EDGE_NO_OP,null);
            mBufferedImage = cOp.filter(mBufferedImage,null);
 
            File targetDir = targetFile.getParentFile();
            if (!targetDir.exists())
                targetDir.mkdirs();
 
            FileOutputStream out = new FileOutputStream(targetFile);
            JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);
            encoder.encode(mBufferedImage);
            out.close();
        } catch (Exception e) {
            logger.error(
                    "imageScale(String,String,int,int) - 图片压缩出错 - srcFilePath="
                            + srcFile.getPath() + ",targeFilePath="
                            + targetFile.getPath() + ",width=" + width
                            + ",height=" + height,e);
        }
    }
 
    public void imageScale(FileItem fileItem,int height) {
        try {
            InputStream input = fileItem.getInputStream();
            Image image = javax.imageio.ImageIO.read(input);
 
            image = image.getScaledInstance(width,Image.SCALE_AREA_AVERAGING);
            BufferedImage mBufferedImage = new BufferedImage(width,BufferedImage.TYPE_INT_RGB);
            Graphics2D g2 = mBufferedImage.createGraphics();
 
            g2.drawImage(image,null);
 
            File target = new File(targetFilePath);
            File targetDir = target.getParentFile();
            if (!targetDir.exists())
                targetDir.mkdirs();
 
            FileOutputStream out = new FileOutputStream(targetFilePath);
            JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);
            encoder.encode(mBufferedImage);
            out.close();
            input.close();
        } catch (Exception e) {
            logger.error(
                    "imageScale(String,int) - 图片压缩出错 - fileItem="
                            + fileItem.getName() + ",targetFilePath="
                            + targetFilePath + ",width=" + width + ",height="
                            + height,e);
        }
    }
     
    public static void main(String[] args) {
        ImageUtil iu=new ImageUtil();
        iu.imageScale("c:/uploadFiles/191540095661.jpg","c:/uploadFiles/t.jpg",270,220);
    }
}