图片缩放

package com.jiwu.utils;

import java.awt.*;
import java.io.*;
import java.awt.image.*;
import com.sun.image.codec.jpeg.*;
import org.apache.commons.logging.LogFactory;
import org.apache.commons.logging.Log;
import org.apache.commons.io.*;

/**
 * @author jxialiang
 * @date 2007-09-27
 */
public class ImgUtil {

  private static final Log logger = LogFactory.getLog(ImgUtil.class);

  public ImgUtil() {
  }

  public static void reduceImg(String imgsrc, String imgdist, int widthdist,
                               int heightdist) {
    try {
      File srcfile = new File(imgsrc);
      if (!srcfile.exists()) {
        return;
      }
      Image src = javax.imageio.ImageIO.read(srcfile);
      int width = src.getWidth(null);
      int height = src.getHeight(null);

      if (width <= widthdist && height <= heightdist) {
        //SysUtil.cpoyFile(imgsrc, imgdist);
        FileUtils.copyFile(new File(imgsrc), new File(imgdist));
        return;
      }

      //宽度除以高度的比例
      float wh = (float) width / (float) height;

      if (wh > 1) {
        float tmp_heigth = (float) widthdist / wh;
        BufferedImage tag = new BufferedImage(widthdist, (int) tmp_heigth,
                                              BufferedImage.TYPE_INT_RGB);
        tag.getGraphics().drawImage(src, 0, 0, widthdist, (int) tmp_heigth, null);
        FileOutputStream out = new FileOutputStream(imgdist);
        JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);
        encoder.encode(tag);
        out.close();
      }
      else {
        if (width <= widthdist && wh > 0.1f) {
          FileUtils.copyFile(new File(imgsrc), new File(imgdist));
          return;
        }
        if (width > widthdist && wh > 0.1f) {
          float tmp_heigth = (float) widthdist / wh;
          BufferedImage tag = new BufferedImage(widthdist, (int) tmp_heigth,
                                                BufferedImage.TYPE_INT_RGB);
          tag.getGraphics().drawImage(src, 0, 0, widthdist, (int) tmp_heigth, null);
          FileOutputStream out = new FileOutputStream(imgdist);
          JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);
          encoder.encode(tag);
          out.close();
          return;
        }

        float tmp_width = (float) heightdist * wh;
        BufferedImage tag = new BufferedImage( (int) tmp_width, heightdist,
                                              BufferedImage.TYPE_INT_RGB);
        tag.getGraphics().drawImage(src, 0, 0, (int) tmp_width, heightdist, null);
        FileOutputStream out = new FileOutputStream(imgdist);
        JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);
        encoder.encode(tag);
        out.close();

      }
    }
    catch (IOException ex) {
      logger.error(ex);
    }
  }
 
 
  //生成原始图片到特定磁盘位置
  public static void createOrgImage(File srcFile,File dstFile){
  try {
   FileUtils.copyFile(srcFile, dstFile);
  } catch (IOException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  }
  //return dstPath;
  }
 
 
  //生成缩略图
  //其中saveImagePath 为原始图片的全路径,saveThumbBasePath保存缩略图基路径，fileName文件名，width，height生成缩略图宽，高
  //public static void createThumb(String saveOrgImagePath,String saveThumbBasePath,String location,String fileName,int width,int height){
  public static void createThumb(String srcImagePath,String distImagePath,int width,int height){
  String imgdist = distImagePath;
  String imgsrc = srcImagePath;
  reduceImg(imgsrc, imgdist, width, height);
  }

  public static void main(String [] args){
   ImgUtil i  = new ImgUtil();
   i.reduceImg("D:/2679321.jpg", "D:/usernoface.gif", 48, 48);
  }
 
}