图片大小压缩

package com.baosight.ec.userCenter.seller.action;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.PrintWriter;
import java.net.SocketException;
import java.util.ArrayList;
import java.util.Hashtable;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.ResourceBundle;

import org.apache.commons.net.ftp.FTP;
import org.apache.commons.net.ftp.FTPClient;
import org.apache.commons.net.ftp.FTPReply;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.upload.FormFile;

import com.baosight.ec.common.Constants;
import com.baosight.ec.common.EcBaseAction;
import com.baosight.web.struts.BActionContext;
import com.bsteel.exchange.client.common.util.PropertiesUtil;
/**

图片管理 *
@author
@date 2013-11-1 下午2:23:52
*/
public class ImgManageAction extends EcBaseAction {
@Override
public ActionForward doDefault(BActionContext context) throws Exception {
// TODO Auto-generated method stub
return null;
}
/*
- 图片上传
  */
  @SuppressWarnings("unchecked")
  public void uploadImg(BActionContext context) throws IOException{
  ActionForm beanForm = context.getForm();
  String msg = "";
  String path = "";
  StringBuilder json = new StringBuilder();
  Hashtable fileh = beanForm.getMultipartRequestHandler().getFileElements();
  List fileList= new ArrayList();
  for (Iterator it = fileh.keySet().iterator(); it.hasNext();) {
  String key = it.next();
  FormFile formfile = fileh.get(key);
  if(formfile.getFileSize()>0){
  fileList.add(formfile);
  }
  }
  if(fileList.size()>0){
  FormFile file = fileList.get(0);
  if(file!=null){
  int i = file.getFileSize();
  if(file.getFileSize()<=500*1024){
  try {
  path = upload(fileList.get(0));
  msg = "上传成功";
  } catch (Exception e) {
  msg = "错误:"+e.getMessage();
  }
  }else{
  msg = "tooLarge";
  }
```
}
```
  }
  json.append("{path:'"+path+"',msg:'"+msg+"'}");
  context.getResponse().setContentType("text/html;charset=UTF-8");
  PrintWriter printWriter = context.getResponse().getWriter();
  printWriter.write(json.toString());
  printWriter.flush();
  printWriter.close();
}
private String upload(FormFile file) throws IOException{
String serverFileName ="";
if(file!=null){
//ResourceBundle rb = ResourceBundle.getBundle(Constants.SYSTEM.PROPERTIES_FILE);
String filePath = Constants.IMAGE_UPLOAD_PATH;
//本机测试用的路径，不上传
//filePath="D:\upload\";
System.out.println("========filePath======="+filePath);
//String runFlag = rb.getString("run.flag");//标识是在哪台服务器上运行(a：103，b：68）
//System.out.println("此服务器的运行标识是：=========》"+runFlag+"<==========");
```
    //判断要上传的文件目录是否存在，如果不存在则创建目录
    File tempfile = new File(filePath);
    if(!tempfile.exists()){
        tempfile.mkdir();
    }

    //图片上传服务器
    String path = null;
    String localFileName =file.getFileName();
    serverFileName = System.currentTimeMillis()+localFileName.substring(localFileName.lastIndexOf("."));
    path = filePath+serverFileName;

    FileOutputStream fos = null;
    try {
        fos = new FileOutputStream(path);
        fos.write(file.getFileData());
        fos.flush();
        fos.close();

       System.out.println("FTP服务器传送文件开始！！！");
       boolean transFlag=this.transFile(path,serverFileName);
       if(transFlag){//传送成功后，删除原路径的文件
           boolean deleFlag=new File(path).delete();
           if(deleFlag){
               System.out.println("文件：====>"+path+"<====删除成功!");
           }                       
       }else {//上传文件失败
        System.out.println("文件：====>"+path+"<====上传失败!");
       }

    } catch (Exception e) {
        e.printStackTrace();
    } finally{//关闭资源
        if(fos!=null){
            fos.close();
        }           
    }
}
return serverFileName;
```
}
/**
- 将本地服务器的文件传输到目标服务器指定目录
- @param path 本地服务器的文件名(完整路径)
- @param serverFileName 根据系统时间重命名的文件名
- @throws SocketException
- @throws IOException
  */
  private boolean transFile(String path, String serverFileName) throws SocketException, IOException {
  //判断文件是否传送成功的标识
  boolean result=false;
  String ftpAddress = Constants.FTP_ADDRESS;
  String ftpUser = Constants.FTP_USER;
  String ftpPassword = Constants.FTP_PASSWORD;
  String imageTargetDir = Constants.FTP_TARGETDIR;
  //测试用的URL和路径
  //ftpAddress="10.60.17.145";
  //imageTargetDir="/export/home/jboss/jboss/jboss-3.2/server/default/deploy/webdocs.war/baozypj/upload_image/";
  System.out.println("========ftpAddress======="+ftpAddress);
  System.out.println("========ftpUser======="+ftpUser);
  System.out.println("========ftpPassword======="+ftpPassword);
  System.out.println("========imageTargetDir======="+imageTargetDir);
  FTPClient ftp=new FTPClient();
  ftp.connect(ftpAddress);//连接服务器
  ftp.login(ftpUser, ftpPassword);//登录
  //判断连接是否成功
  int reply=ftp.getReplyCode();
  if(!FTPReply.isPositiveCompletion(reply)){
  System.out.println("连接失败");
  ftp.disconnect();
  return false;
  }
  //String workPath = filePath;//工作目录名
  String workPath = imageTargetDir;
  String remoteFileName=imageTargetDir+serverFileName;//远程文件名
  Boolean b=ftp.changeWorkingDirectory(workPath);//设置工作目录
  System.out.println("目标服务器文件名（全路径）:=======>"+remoteFileName+"<==========");
  //FileInputStream fis2=new FileInputStream(path);
  File remoteFile=new File(path);//以本地服务器的文件作为输入流
  //System.out.println("文件的大小为："+remoteFile.length());
  FileInputStream fis2=new FileInputStream(remoteFile);
  ftp.setFileType(FTP.BINARY_FILE_TYPE);
  if(b){
  Boolean b2=ftp.storeFile(new String(remoteFileName.getBytes(),"iso-8859-1"), fis2);
  if(b2){
  System.out.println("上传成功!图片的大小为："+remoteFile.length()+"字节");
  if(remoteFile.length()>0){
  result=true;
  }
  
  }
  fis2.close();
  ftp.logout();
  }
  return result;
  
  }
/*
- 本地图片删除 */ public void deletePic(BActionContext context) throws IOException { // ResourceService resourceService = (ResourceService)context.findService("resourceService", ResourceService.class); String filePath = Constants.IMAGE_UPLOAD_PATH; String imgName = context.getRequest().getParameter("imgName"); String msg = ""; boolean r = false; File file = new File(filePath+imgName); if(file.exists()){ r = file.delete(); if(r){ // resourceService.deleteResourceImgByImgName(imgName); msg = "0"; }else{ msg = "删除错误"; } } context.getResponse().setContentType("text/html;charset=UTF-8"); PrintWriter printWriter = context.getResponse().getWriter(); printWriter.write(msg); }

}
这是我这里的图片上传代码
我想在上传代码哪里的判断图片大于500KB的方法里加入一个图片压缩方法，当图片大于500KB进入此方法进行压缩为更小的KB，然后返回处理过的图片在进入上传图片方法上传！请问代码怎么写

package com.kay.util;

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.Date;
import java.awt.image.BufferedImage;
import java.awt.Image;
import java.awt.image.AffineTransformOp;
import javax.imageio.ImageIO;
import java.awt.geom.AffineTransform;

public class ImageModify {
/**
* @param filePath
* 图片的原始目录
* @param dirPath
* 处理后的图片存放目录
* @param file
* 原始图片
* @param dirName
* 处理后的图片文件名前缀
* @throws Exception
*
*/
public static void main(String []args) throws Exception{
// ImageModify m=new ImageModify();
// String filePath="f://image";
// String dirPath="f://image";
// String file="a.gif";
// String dirName="img"+(new Date()).getTime();
// if(m.modify(filePath,dirPath,file,dirName)){
// System.out.println("图像处理成功！");
// }
}
public static void modify(String filePath,String dirPath,String file,String dirName) throws Exception {
// ext是图片的格式 gif JPG 或png
String ext = "";
double Ratio = 0.0;
File F = new File(filePath, file);

// if (!F.isFile())
// throw new Exception(F
// + " is not image file error in CreateThumbnail！");
// 首先判断上传的图片是gif还是JPG ImageIO只能将gif转换为png
// if (isJpg(imgfile)) {
// ext = "jpg";
// } else {
ext = "jpg";
// }
File dir=new File(dirPath);
if(!dir.exists()){
dir.mkdir();
}
File ThF = new File(dirPath, dirName);
if(!ThF.exists()){
ThF.createNewFile();
}
BufferedImage Bi = ImageIO.read(F);
// 假设图片宽高最大为120 120
Image Itemp = Bi.getScaledInstance(120, 120, Bi.SCALE_SMOOTH);
if ((Bi.getHeight() > 120) || (Bi.getWidth() > 120)) {
if (Bi.getHeight() > Bi.getWidth())
Ratio = 120.0 / Bi.getHeight();
else
Ratio = 120.0 / Bi.getWidth();
}
AffineTransformOp op = new AffineTransformOp(AffineTransform
.getScaleInstance(Ratio, Ratio), null);
Itemp = op.filter(Bi, null);
try {
ImageIO.write((BufferedImage) Itemp, ext, ThF);
} catch (Exception ex) {
throw new Exception(" ImageIo.write error in CreatThum.： "
+ ex.getMessage());
}
// return (true);
}

public static void upload(File file, String fileName, String path) throws IOException{
    InputStream is = null;
    OutputStream os = null;
    try
    {
        File dir = new File(path);
        if (!dir.exists())
        {
            dir.mkdirs();
        }
        if (!file.exists())
        {
            file.createNewFile();
        }
        is = new FileInputStream(file.toString());

        String name = fileName.trim().toString();// 得到上传文件的原名称
        File destFile = new File(path, name);

        os = new FileOutputStream(destFile);

        byte[] buffer = new byte[400];

        int length = 0;

        while ((length = is.read(buffer)) > 0)
        {
            os.write(buffer, 0, length);
        }

    }
    catch (Exception e)
    {
        e.printStackTrace();
    }
    finally
    {
        is.close();
        os.close();
    }

}

}
不晓得这个是不是你要的效果