文件的下载
 1.程序代码如下：
 packageeduask;
 importjava.io.FileInputStream;
 importjava.io.IOException;
 importjava.io.InputStream;
 importjava.io.OutputStream;
 importjava.net.URLEncoder;
 importjavax.servlet.ServletException;
 importjavax.servlet.http.HttpServlet;
 importjavax.servlet.http.HttpServletRequest;
 importjavax.servlet.http.HttpServletResponse;
 //文件的下载;
 publicclassFileLoadextendsHttpServlet {
 @Override
 protectedvoidservice(HttpServletRequest req, HttpServletResponse resp)
 throwsServletException, IOException {
 //设置响应编码方式;
 resp.setCharacterEncoding("utf-8");
 resp.setContentType("text/html;charset=utf-8");
 //获得下载文件绝对路径;
 String path=this.getServletContext().getRealPath("/downLoad/Tomcat.doc");
 String fileName=path.substring(path.lastIndexOf("\\")+1);
 //编码;
 fileName=URLEncoder.encode(fileName, "utf-8");
 resp.setHeader("Content-Disposition", "attachment;filename="+fileName);
 //创建一个输入对象流;
 InputStream is=newFileInputStream(path);
 //创建一个输出对象流;
 OutputStream out=resp.getOutputStream();
 intlen=0;
 byte[] b=newbyte[1024];
 while((len=is.read(b))>0){
 out.write(b, 0, len);
 }
 }
 }
 2.web.xml配置文件，配置如下：
 <!--文件的下载-->
 <servlet>
 <servlet-name>FileLoad</servlet-name>
 <servlet-class>eduask.FileLoad</servlet-class>
 </servlet>
 <servlet-mapping>
 <servlet-name>FileLoad</servlet-name>
 <url-pattern>/FileLoad</url-pattern>
 </servlet-mapping>