Java上傳圖片，對圖片進行等比例縮放，及局部裁剪的工具類代碼

import java.awt.Container;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.MediaTracker;
import java.awt.Rectangle;
import java.awt.RenderingHints;
import java.awt.Toolkit;
import java.awt.image.BufferedImage;
import java.awt.image.CropImageFilter;
import java.awt.image.FilteredImageSource;
import java.awt.image.ImageFilter;
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.UUID;

import javax.imageio.ImageIO;
import com.sun.image.codec.jpeg.JPEGCodec;
import com.sun.image.codec.jpeg.JPEGEncodeParam;
import com.sun.image.codec.jpeg.JPEGImageEncoder;
public class FileUploadUtils {

/**
 * 裁剪圖片 
 * @param input
 * @param basepath
 * @param uid
 * @param x
 * @param y
 * @param width
 * @param height
 * @return 絕對路徑
 * @throws IOException 
 */
public static String cutImg(String input,String basepath,int x,int y,int width,int height) throws IOException{
    String path2 = basepath+"/"+ConstantUtils.USERFACETEMPPATH;
    String postfix = getPostfix(input);
    String dst = path2 +"/"+UUID.randomUUID().toString()+"."+postfix;

    createDir(path2);
    imgCut(basepath+input,dst,postfix,x,y,width,height);

    return dst;
}

/**
 * 裁剪圖片
 * @param input
 * @param src
 * @param x
 * @param y
 * @param width
 * @param height
 * @throws IOException
 */
public static void imgCut(String input,String dst,String type,int x,int y,int width,int height) throws IOException
 {
        BufferedImage fromimg = ImageIO.read(new File(input));
        ImageFilter cropFilter = new CropImageFilter(x,y,width,height);   
        Image img = Toolkit.getDefaultToolkit().createImage(new FilteredImageSource(fromimg.getSource(), cropFilter));
        BufferedImage tag = new BufferedImage(width,height, BufferedImage.TYPE_INT_RGB);  

        Graphics g = tag.getGraphics();   
        g.drawImage(img, 0, 0, null); // 繪制小圖   
       g.dispose();   
        // 輸出為文件   
       // dir = "d:\\temp\\cut_image_" + i + "_" + j + ".jpg";   
        File f = new File(dst);   
        ImageIO.write(tag,type, f);  

    }


/**
 * 上傳頭像文件
 * @param src
 * @param basepath
 * @param filename
 * @return
 * @throws Exception
 */
public static String uploadImg(File src,String basepath,String filename) throws Exception{
    String daypath = DateTools.getYear() + "" + DateTools.getMonth() + "" + DateTools.getMonthWeek();

    String temppath = ConstantUtils.BASEUPLOADPATH+"/"+ConstantUtils.ORIGINALIMGPATH+"/" + daypath;
    String thumbnailpath = ConstantUtils.BASEUPLOADPATH+"/"+ConstantUtils.THUMBNAILIMGPATH+"/" + daypath;

    String postfix = getPostfix(filename);
    String uuid = UUID.randomUUID().toString();
    String dsttempname = uuid+"."+postfix;

    createDir(basepath +"/"+temppath);
    createDir (basepath +"/"+ thumbnailpath);


    String dstallpath = basepath +"/"+temppath+"/"+dsttempname;
    String dstthumbnailpath = basepath +"/"+thumbnailpath+"/"+dsttempname;

    copy(src,new File(dstallpath));

    //對上傳的文件進行 等比例 裁剪。  按照前段要展現的  height width
    Thumbnail(dstallpath,dstthumbnailpath,350,300,100);

    //返回裁剪后的路徑 

    return thumbnailpath+"/"+dsttempname;
}

/**
 * 上傳文件
 * @param src
 * @param dst
 * @throws Exception
 */
public static void copy(File src, File dst) throws Exception {
    try {
        InputStream in = null;
        OutputStream out = null;
        try {
            in = new BufferedInputStream(new FileInputStream(src), ConstantUtils.BUFFER_SIZE);
            out = new BufferedOutputStream(new FileOutputStream(dst), ConstantUtils.BUFFER_SIZE);
            byte[] buffer = new byte[ConstantUtils.BUFFER_SIZE];
            while (in.read(buffer) > 0) {
                out.write(buffer);
            }
        } finally {
            if (null != in) {
                in.close();
            }
            if (null != out) {
                out.close();
            }
        }
    } catch (Exception e) {
        e.printStackTrace();
        throw e;
    }
}

/**
 * 得到文件后綴  jpg  
 * @param fileName
 * @return
 */
public static String getPostfix(String fileName){
    if (fileName.equals(""))
        return "";
    int pos = fileName.lastIndexOf(".");
    if (pos < 0) {
        return fileName.substring(fileName.length() - 3).toLowerCase();
    } else {
        return fileName.substring(pos+1).toLowerCase();
    }
}

/**
 * 創建目錄
 * @param filePath
 */
public static void createDir(String filePath) {
    File myFile = new File(filePath);
    if (!myFile.exists()) {
        if (!myFile.mkdirs())
            System.out.println("創建目錄 fail");
        else
            System.out.println("創建目錄 success");
    }
    myFile = null;
}

/**
 * 等比例縮放圖片
 * @param infile
 * @param outfile
 * @param width
 * @param height
 * @param quality
 * @throws IOException
 * @throws InterruptedException
 */
public static void Thumbnail(String infile, String outfile, int width, int height, int quality) throws IOException, InterruptedException {
    // save thumbnail image to OUTFILE
    //System.out.println("infile:" + infile);
    BufferedImage thumbImage = null;
    BufferedOutputStream out = null;
    Image image = null;
    image = Toolkit.getDefaultToolkit().createImage(infile);
    MediaTracker mediaTracker = new MediaTracker(new Container());
    mediaTracker.addImage(image, 0);
    mediaTracker.waitForID(0);
    int thumbWidth = width;
    int thumbHeight = height;
    double thumbRatio = (double) thumbWidth / (double) thumbHeight;
    int imageWidth = image.getWidth(null);
    int imageHeight = image.getHeight(null);
    double imageRatio = (double) imageWidth / (double) imageHeight;
    if (thumbRatio < imageRatio) {
        thumbHeight = (int) (thumbWidth / imageRatio);
    } else {
        thumbWidth = (int) (thumbHeight * imageRatio);
    }
    thumbImage = new BufferedImage(thumbWidth, thumbHeight, BufferedImage.TYPE_INT_RGB);
    Graphics2D graphics2D = thumbImage.createGraphics();
    graphics2D.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BILINEAR);
    graphics2D.drawImage(image,0,0, thumbWidth, thumbHeight, null);
    out = new BufferedOutputStream(new FileOutputStream(outfile));
    JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);
    JPEGEncodeParam param = encoder.getDefaultJPEGEncodeParam(thumbImage);
    quality = Math.max(0, Math.min(quality, 100));
    param.setQuality((float) quality / 100.0f, false);
    encoder.setJPEGEncodeParam(param);
    encoder.encode(thumbImage);
    out.close();
    thumbImage = null;
    out = null;
    image = null;
}

}</pre>