关于图片上传与下载(Java)

图片的上传

package com.upload;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.jsp.JspFactory;
import javax.servlet.jsp.PageContext;

import com.jspsmart.upload.File;
import com.jspsmart.upload.SmartUpload;
import com.jspsmart.upload.SmartUploadException;

@SuppressWarnings("serial")
public class DoUploadServlet extends HttpServlet {
 public void doPost(HttpServletRequest request, HttpServletResponse response)
   throws ServletException, IOException {
  response.setContentType("text/html;charset=GB2312");
  PrintWriter out = response.getWriter();
  // 新建一个SmartUploaf对象
  SmartUpload su = new SmartUpload();
  // 得到PageContext对象
  PageContext pageContext = JspFactory
    .getDefaultFactory()
    .getPageContext(this, request, response, null, true, 8192, true);
  // 上传初始化
  su.initialize(pageContext);

try {
   // 上传文件
   su.upload();
   // 将文件保存到指定的目录,并返回上传文件数
   int count = su.save("/js");
   out.print("<center>"+count + "个文件上传成功!<br>" + su.toString()+"</center>");
  } catch (SmartUploadException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  }
  out
    .print("  <style type='text/css'>"
      + "<!--"
      + ".STYLE3 {"
      + " font-size: 12px"
      + "}"
      + "-->"
      + "</style>"
      + " <table width='600' border='1' id='tableInfo'"
      + "  style='border: 1px solid #CCCCCC; '"
      + "  cellpadding='0' cellspacing='0' align='center'>");
  // 逐一提取上传文件信息,同事保存文件
  for (int i = 0; i < su.getFiles().getCount(); i++) {
   File file = su.getFiles().getFile(i);
   // 显示当前文件信息

out
     .print("  <tr>"
       + "   <td width='28%'>"
       + "    <div align='right' class='STYLE3'>"
       + "     表单项名(getFieldName)：           </div>          </td>"
       + "   <td width='72%'>"
       + file.getFieldName()
       + "          </td>"
       + "  </tr>"
       + "  <tr>"
       + "   <td>"
       + "    <div align='right' class='STYLE3'>"
       + "     文件长度(getSize)：           </div>          </td>"
       + "   <td>"
       + file.getSize()
       + "         </td>"
       + "  </tr>"
       + "  <tr>"
       + "   <td>"
       + "    <div align='right' class='STYLE3'>"
       + "     文件名(getFileName)：           </div>          </td>"
       + "   <td>"
       + file.getFileName()
       + "         </td>"
       + "  </tr>"
       + "  <tr>"
       + "   <td>"
       + "    <div align='right' class='STYLE3'>"
       + "     文件扩展名(getFileExt)：           </div>          </td>"
       + "   <td>"
       + file.getFileExt()
       + "          </td>"
       + "  </tr>"
       + "  <tr>"
       + "   <td>"
       + "    <div align='right' class='STYLE3'>"
       + "     文件全名(getFilePathName)：           </div>          </td>"
       + "   <td>"
       + file.getFilePathName()
       + "          </td>" + "  </tr>");
  }
  out.print(" </table>");
 }
}

图片的下载

package com.upload;

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.jsp.JspFactory;
import javax.servlet.jsp.PageContext;

import com.jspsmart.upload.SmartUpload;
import com.jspsmart.upload.SmartUploadException;

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

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

this.doPost(request, response);
 }

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

response.setContentType("text/html;charset=GB2312");
  //得到 要下载的文件的名称
  String fileName=new String(request.getParameter("fileName").getBytes("ISO8859-1"),"GB2312");
  //得到SmartUpload对象
  SmartUpload su=new SmartUpload();
  //得到PageContext对象
  PageContext pagecontext=JspFactory.getDefaultFactory().getPageContext(this, request, response, null, true, 8192, true);
  //初始化su
  su.initialize(pagecontext);
  //下载
  
  su.setContentDisposition(null);
  try {
   su.downloadFile("/js/"+fileName);
  } catch (SmartUploadException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  }
 }

}

相关jar包:http://www.cnblogs.com/cz-xjw/admin/Files.aspx