Servlet – Read Select Box Value

In this tutorials we are going to see how to read select box value using servlet program.
Step by step instructions given below .
1. Create new Dynamic web project by choosing File –> New –> Dynamic Web Project .
2. Create the Project called ServletExample as given below.

3. Create package called com.javatutorialscorner.servlet under ServletExample.
4. Create Servlet called SelectBoxServlet as shown in figure.

5. Click Next it will show URL mapping.You can edit Servlet URL if you need.
6. Click Next it will show methods available in HttpServlet. Select appropriate method you need.

7. By default your servlet will be mapped in web.xml, if your servlet not mapped in your web.xml use the following configuration to map the servlet in your web.xml
Servlet Mapping

<servlet>
    <servlet-name>Your Servlet Name</servlet-name>
    <servlet-class>Fully Qulaified Servlet Class Name</servlet-class>
  </servlet>
  <servlet-mapping>
    <servlet-name>Your Servlet Name</servlet-name>
    <url-pattern>/URL to Call Servlet</url-pattern>
  </servlet-mapping>

web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0">
  <display-name>ServetExample</display-name>
  <welcome-file-list>
    <welcome-file>index.html</welcome-file>
    <welcome-file>index.htm</welcome-file>
    <welcome-file>index.jsp</welcome-file>
    <welcome-file>default.html</welcome-file>
    <welcome-file>default.htm</welcome-file>
    <welcome-file>default.jsp</welcome-file>
  </welcome-file-list>
  <servlet>
    <servlet-name>SelectBoxServlet</servlet-name>
    <servlet-class>com.javatutorialscorner.servlet.SelectBoxServlet</servlet-class>
  </servlet>
  <servlet-mapping>
    <servlet-name>SelectBoxServlet</servlet-name>
    <url-pattern>/SelectBoxServlet</url-pattern>
  </servlet-mapping>
</web-app>

8. Add the required code inside doPost() method.

SelectBoxServlet.java

package com.javatutorialscorner.servlet;

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;

/**
 * Servlet implementation class SelectBoxServlet
 */

public class SelectBoxServlet extends HttpServlet {
 private static final long serialVersionUID = 1L;
       
    /**
     * @see HttpServlet#HttpServlet()
     */
    public SelectBoxServlet() {
        super();
        // TODO Auto-generated constructor stub
    }

 /**
  * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
  */
 protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
  // TODO Auto-generated method stub
 }

 /**
  * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
  */
 protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
  // TODO Auto-generated method stub
  response.setContentType("text/html");
  PrintWriter writer = response.getWriter();
  String[] technologies = request.getParameterValues("multi-select");
  writer.write("<!DOCTYPE html PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\" \"http://www.w3.org/TR/html4/loose.dtd\">\n"
    + "<html><head><meta http-equiv=\"Content-Type\" content=\"text/html; charset=ISO-8859-1\"><title>Java Tutorials Corner - Servlet - Submit Checkbox Data</title>"
    + "</head><body><h1>Java Tutorials Corner - Servlet - Submit Checkbox Data</h1><table><tr>"
    + "<td>Experience : </td><td>"
    + request.getParameter("single-select")
    + "</td></tr><tr><td>Technology  : </td><td>");
   for (String values : technologies) {
    writer.write( values+"<br/>");
   }
    writer.write( "</td></tr>"
    +"</table></body></html>");
 }

}

In above servlet multiple values are submitted as String[] array so, I used request.getParameterValues("multi-select"); to get all vales as String[]. If you use request.getParameter("multi-select") ; first value alone readable .

9. Create html page in WebContent folder

selectboxform.html

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Java Tutorials Corner - Servlet - Select Box</title>
</head>
<body>
 <h1>Java Tutorials Corner - Servlet - Select Box</h1>
 <form action="SelectBoxServlet" method="post">

  <table>

   <tr>
    <td>Experience :</td>
    <td><select>
      <option value="fresher">Fresher</option>
      <option value="experienced">Experience</option>
    </select></td>
   </tr>
   <tr>
    <td>Technology :</td>
    <td><select multiple="multiple" size="5">
      <option value="Java">Java</option>
      <option value="Servlet">Servlet</option>
      <option value="JSP">JSP</option>
      <option value="Spring">Spring</option>
      <option value="Struts">Struts</option>
      <option value="Hibernate">Hibernate</option>
      <option value="Web Service">Web Service</option>
      <option value="XML">XML parsing</option>
      <option value="JSON">JSON</option>
    </select></td>
   </tr>
  </table>

  <input type="submit" value="Submit" />
 </form>
</body>
</html>

In above html page in form tag method="post"to mention the form submit using post method.The default method to submit form is GET.

9. Now save and Run the servlet, Run As –> Run on Server – Select your web Server to run the servlet. ( see How to configure tomcat in eclipse)
http://www.javatutorialcorner.com/2014/03/how-to-configure-tomcat-in-eclipse.html

10.call the following URL .

http://localhost:8080/ServletExample/selectboxform.html

Output