servlet用jspsmart上传的时候获得pageContext对象
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
import com.jspsmart.upload.*;
import javax.servlet.jsp.*;
public class Hello extends HttpServlet {
    public void doPost(HttpServletRequest request,
      HttpServletResponse response)
      throws ServletException, IOException {
       request.setCharacterEncoding("gb2312");
       response.setContentType("text/html;charset=gb2312");
    
       PrintWriter out = response.getWriter();
       SmartUpload su = new SmartUpload();
       try{
       JspFactory _jspxFactory = null;
       PageContext pageContext = null;
       _jspxFactory = JspFactory.getDefaultFactory();
       pageContext = _jspxFactory.getPageContext(this,request,response,"",true,8192,true);
    
    
       su.initialize(pageContext);
       su.upload();
       com.jspsmart.upload.File file = su.getFiles().getFile(0);
       file.saveAs("upload/"+file.getFileName());
       pageContext.forward("index.htm");
       }catch(Exception e){
     
       }




其实在jsp中有的对象，在servlet不知道怎么用的话可以先编译jsp，然后在服务器的work目录中找到jsp所对应的servlet文件，找到相应的代码就可以了，因为jsp最终也会被编译成servlet文件。