Java Tutorial/Servlet/Form

Материал из Java эксперт
Версия от 17:44, 31 мая 2010; (обсуждение)
(разн.) ← Предыдущая | Текущая версия (разн.) | Следующая → (разн.)
Перейти к: навигация, поиск

Get Form Text Field as a Servlet parameter

import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class MyServlet extends HttpServlet {
  public void doGet(HttpServletRequest req, HttpServletResponse res)
                               throws ServletException, IOException {
    res.setContentType("text/html");
    PrintWriter out = res.getWriter();
    String name = req.getParameter("name");
    out.println("<HTML>");
    out.println("<HEAD><TITLE>Hello, " + name + "</TITLE></HEAD>");
    out.println("<BODY>");
    out.println("Hello, " + name);
    out.println("</BODY></HTML>");
  }
  public String getServletInfo() {
    return "A servlet that knows the name of the person to whom it"s" + 
           "saying hello";
  }
}





Servlet Based GuestBook

import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
import java.util.*;
public class MyServlet extends HttpServlet {
  
  private Vector entries = new Vector();  
  private long lastModified = 0;          
  
  public void doGet(HttpServletRequest req, HttpServletResponse res) 
                               throws ServletException, IOException {
    res.setContentType("text/html");
    PrintWriter out = res.getWriter();
    printHeader(out);
    printForm(out);
    printMessages(out);
    printFooter(out);
  }
  // Add a new entry, then dispatch back to doGet()
  public void doPost(HttpServletRequest req, HttpServletResponse res) 
                                throws ServletException, IOException {
    handleForm(req, res);
    doGet(req, res);
  }
  private void printHeader(PrintWriter out) throws ServletException {
    out.println("<HTML><HEAD><TITLE>Guestbook</TITLE></HEAD>");
    out.println("<BODY>");
  }
  private void printForm(PrintWriter out) throws ServletException {
    out.println("<FORM METHOD=POST>");  // posts to itself
    out.println("<B>Please submit your feedback:</B><BR>");
    out.println("Your name: <INPUT TYPE=TEXT NAME=name><BR>");
    out.println("Your email: <INPUT TYPE=TEXT NAME=email><BR>");
    out.println("Comment: <INPUT TYPE=TEXT SIZE=50 NAME=comment><BR>");
    out.println("<INPUT TYPE=SUBMIT VALUE=\"Send Feedback\"><BR>");
    out.println("</FORM>");
    out.println("<HR>");
  }
  private void printMessages(PrintWriter out) throws ServletException {
    String name, email, comment;
    Enumeration e = entries.elements();
    while (e.hasMoreElements()) {
      GuestbookEntry entry = (GuestbookEntry) e.nextElement();
      name = entry.name;
      if (name == null) name = "Unknown user";
      email = entry.email;
      if (name == null) email = "Unknown email";
      comment = entry.rument;
      if (comment == null) comment = "No comment";
      out.println("<DL>");
      out.println("<DT><B>" + name + "</B> (" + email + ") says");
      out.println("<DD><PRE>" + comment + "</PRE>");
      out.println("</DL>");
      // Sleep for half a second to simulate a slow data source
      try { Thread.sleep(500); } catch (InterruptedException ignored) { }
    }
  }
  private void printFooter(PrintWriter out) throws ServletException {
    out.println("</BODY>");
  }
  private void handleForm(HttpServletRequest req,
                          HttpServletResponse res) {
    GuestbookEntry entry = new GuestbookEntry();
    entry.name = req.getParameter("name");
    entry.email = req.getParameter("email");
    entry.rument = req.getParameter("comment");
    entries.addElement(entry);
    // Make note we have a new last modified time
    lastModified = System.currentTimeMillis();
  }
  public long getLastModified(HttpServletRequest req) {
    return lastModified;
  }
}
class GuestbookEntry {
  public String name;
  public String email;
  public String comment;
}





Servlet Form Processor CheckBox

import javax.servlet.http.*;
import javax.servlet.*;
import java.io.IOException;
public class MyServlet extends HttpServlet
{
  public void doPost (HttpServletRequest req, HttpServletResponse res) throws IOException
  {
    ServletOutputStream out = res.getOutputStream();
    res.setContentType("text/html");
    out.println("<html><head><title>Basic Form Processor Output</title></head>");
    out.println("<body>");
    out.println("<h1>Here is your Form Data</h1>");
    //extract the form data here
    String title = req.getParameter("title");
    String name = req.getParameter("name");
    String city = req.getParameter("city");
    String country = req.getParameter("country");
    String tel = req.getParameter("tel");
    String age = req.getParameter("age");
    // extracting data from the checkbox field
    String[] interests = req.getParameterValues("interests");
    //output the data into a web page
    out.println("Your title is "  + title);
    out.println("<br>Your name is "  + name);
    out.println("<br>Your city is "  + city);
    out.println("<br>Your country is "  + country);
    out.println("<br>Your tel is "  + tel);
    out.println("<br>Your interests include<ul> ");
    for (int i=0;i<interests.length; i++) {
    out.println("<li>" + interests[i]);
  }
  out.println("</ul>");
  out.println("<br>Your age is "  + age);
    out.println("</body></html>");
  }
}





Servlet Post Form Data to Self Servlet

import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
import java.util.*;
public class MyServlet extends HttpServlet {
  public void doGet(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, java.io.IOException {
  System.out.println("command: "+request.getParameter("command"));
    response.setContentType("text/html");
    java.io.PrintWriter out = response.getWriter();
    out.println("<html><head>");
    out.println("<title>Help Page</title></head><body>");
    out.println("<h2>Please submit your information</h2>");
    out.println("<form method=\"post\" action =\"" + request.getContextPath() +"/MyServlet\" >");
    out.println("<table border=\"0\"><tr><td valign=\"top\">");
    out.println("Your first name: </td>  <td valign=\"top\">");
    out.println("<input type=\"text\" name=\"firstname\" size=\"20\">");
    out.println("</td></tr><tr><td valign=\"top\">");
  out.println("Your last name: </td>  <td valign=\"top\">");
    out.println("<input type=\"text\" name=\"lastname\" size=\"20\">");
    out.println("</td></tr><tr><td valign=\"top\">");
    out.println("Your email: </td>  <td valign=\"top\">");
    out.println("<input type=\"text\" name=\"email\" size=\"20\">");
    out.println("</td></tr><tr><td valign=\"top\">");
    out.println("<input type=\"submit\" value=\"Submit Info\"></td></tr>");
    out.println("</table></form>");
    out.println("</body></html>");
     }
   public void doPost(HttpServletRequest request, HttpServletResponse response)
    throws ServletException,java.io.IOException{
  Enumeration paramNames = request.getParameterNames();
  String parName;
  boolean emptyEnum = false;
  if (! paramNames.hasMoreElements())
      emptyEnum = true;

    response.setContentType("text/html");
    java.io.PrintWriter out = response.getWriter();
    out.println("<html><head>");
    out.println("<title>Submitted Parameters</title></head><body>");
  if (emptyEnum){
      out.println("<h2>Sorry, the request does not contain any parameters</h2>");
  } else {
      out.println("<h2>Here are the submitted parameter values</h2>");
  }
  while(paramNames.hasMoreElements()){
      parName = (String) paramNames.nextElement();
      out.println("<strong>" + parName + "</strong> : " + request.getParameter(parName));
      out.println("<br />");
  }
  out.println("</body></html>");
  }
}


Источник — «http://jexp.ru/index.php?title=Java_Tutorial/Servlet/Form&oldid=4901»