jsp源码实例2(获取表单参数)

  package coreservlets;

  import java.io.*;

  import javax.servlet.*;

  import javax.servlet.http.*;

  import java.util.*;

  /** Shows all the parameters sent to the servlet via either

  * GET or POST. Specially marks parameters that have

  * no values or multiple values.

  * <P>

  * Taken from Core Servlets and JavaServer Pages

  * from Prentice Hall and Sun Microsystems Press,

  * http://www.coreservlets.com/.

  * © 2000 Marty Hall; may be freely used or adapted.

  */

  public class ShowParameters extends HttpServlet {

  public void doGet(HttpServletRequest request,

  HttpServletResponse response)

  throws ServletException, IOException {

  response.setContentType("text/html");

  PrintWriter out = response.getWriter();

  String title = "Reading All Request Parameters";

  out.println(ServletUtilities.headWithTitle(title) +

  "<BODY BGCOLOR=\"#FDF5E6\">\n" +

  "<H1 ALIGN=CENTER>" + title + "</H1>\n" +

  "<TABLE BORDER=1 ALIGN=CENTER>\n" +

  "<TR BGCOLOR=\"#FFAD00\">\n" +

  "<TH>Parameter Name<TH>Parameter Value(s)");

  Enumeration paramNames = request.getParameterNames();

  while(paramNames.hasMoreElements()) {

  String paramName = (String)paramNames.nextElement();

  out.print("<TR><TD>" + paramName + "\n<TD>");

  String[] paramValues =

  request.getParameterValues(paramName);

  if (paramValues.length == 1) {

  String paramValue = paramValues[0];

  if (paramValue.length() == 0)

  out.println("<I>No Value</I>");

  else

  out.println(paramValue);

  } else {

  out.println("<UL>");

  for(int i=0; i<paramValues.length; i++) {

  out.println("<LI>" + paramValues);

  }

  out.println("</UL>");

  }

  }

  out.println("</TABLE>\n</BODY></HTML>");

  }

  public void doPost(HttpServletRequest request,

  HttpServletResponse response)

  throws ServletException, IOException {

  doGet(request, response);

  }

  }