poi+servlet+网络图片，将Servlet内容下载到客户端为Excel或Word

package com;

import java.io.*;
import java.net.URL;
import javax.servlet.*;
import javax.servlet.http.*;
import javax.swing.filechooser.FileSystemView;

import com.sun.image.codec.jpeg.*;//sun公司仅提供了jpg图片文件的编码api
import javax.imageio.ImageIO;

import org.apache.poi.hssf.usermodel.HSSFClientAnchor;
import org.apache.poi.hssf.usermodel.HSSFPatriarch;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;

import java.awt.image.BufferedImage;

@SuppressWarnings("serial")
public class Png extends HttpServlet {

 private static final String JPG = "image/jpeg;charset=GB2312";

 public void init() throws ServletException {
 }

 public void doGet(HttpServletRequest request, HttpServletResponse response)
   throws IOException, ServletException {
  doPost(request, response);
 }

 public void doPost(HttpServletRequest request, HttpServletResponse response)
   throws IOException, ServletException {
  response.setContentType("application/vnd.ms-excel");//如果想是Word，把vnd.ms-excel改为msword
     response.setHeader("Content-Disposition", "attachment; filename=admin.xls"); 
 
  BufferedImage bufferImg = null; 
  try {
   URL url = new URL(
     "http://hiphotos.baidu.com/youyu0503/pic/item/3f1e42a7dbc6dfc89152ee19.jpg");
   ByteArrayOutputStream byteArrayOut = new ByteArrayOutputStream();  
   bufferImg = ImageIO.read(url.openStream());  
   ImageIO.write(bufferImg, "jpg", byteArrayOut); 
   // 创建一个工作薄
   HSSFWorkbook wb = new HSSFWorkbook();
   HSSFSheet sheet1 = wb.createSheet("new sheet");   
   HSSFPatriarch patriarch = sheet1.createDrawingPatriarch();
   HSSFClientAnchor anchor = new HSSFClientAnchor(0, 0, 512, 255,
     (short) 0,0, (short) 10, 20);   
   // 插入图片
   patriarch.createPicture(anchor, wb.addPicture(byteArrayOut
     .toByteArray(), HSSFWorkbook.PICTURE_TYPE_JPEG));
   FileSystemView fsv = FileSystemView.getFileSystemView();
   String a=fsv.getHomeDirectory().toString();
 
   // 写入excel文件
   wb.write(response.getOutputStream());
   
  } catch (IOException io) {
   io.printStackTrace();
   System.out.println("io erorr : " + io.getMessage());
  }
 }
}