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Color Selection in servlet

Posted in : Java Posted on : June 27, 2011 at 6:53 PM Comments : [ 0 ]

In this section we will discuss how we can select various colors and displayed it to the user.

Color Selection in servlet

In this section we will discuss how we can select various colors and displayed it to the user.

In the example given below I have created a html page onto which I make an options of choosing colors and a submit button on which by clicking the values we have selected will gone to the server. Further on the server the values which we had selected into the html page will be fetched by the HttpServletRequest's object getParameterValues() method.

Example :

colorSelection.html

<html>
<head>
<title>color's List</title>
</head>
<body>
<form action="/colorSelection/ColorSelection">
<select name="clr" multiple>
<option>Brown</option>
<option>Red</option>
<option>Pink</option>
<option>Blue</option>
<option>White</option>
</select> 
<p><input type="submit" name="submit"/></p></form>
</body>
</html>

ColorSelection.java

import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.Servlet;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

public class ColorSelection extends HttpServlet implements Servlet {

public void doGet(HttpServletRequest req, HttpServletResponse res)
throws ServletException, IOException {
res.setContentType("text/html");
PrintWriter pw = res.getWriter();
HttpSession ssn = req.getSession();
String clrs[] = req.getParameterValues("clr");
if (ssn != null) {
ssn.setAttribute("color", clrs);
ssn.setMaxInactiveInterval(60);
}
pw.println("<html><body bgcolor =cyan>");
for (int i = 0; i < clrs.length; i++) {
pw.println("colors selected :" + clrs[i] + "<br>");
}
pw.println("<form action = /colorSelection/GetColor>");
pw.println("<input type = submit name= submit/>");
pw.println("</form></body></html>");
}
}

GetColor.java

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;
import javax.servlet.http.HttpSession;

public class GetColor extends HttpServlet {
public void doGet(HttpServletRequest req, HttpServletResponse res)
throws ServletException, IOException {
res.setContentType("text/html");
PrintWriter pw = res.getWriter();
HttpSession ssn = req.getSession(false);
if (ssn == null) {
pw.println("No session is available");
pw.println("We are creating a session for you. Creating.....");
ssn = req.getSession();
} else {
String getColors[] = (String[]) ssn.getAttribute("color");
pw.println("<html><body bgcolor = cyan>");
for (int i = 0; i < getColors.length; i++) {
pw.println("colors selected by you are : " + getColors[i] + "<br>");
}
pw.println("<html><body>");
}
}
}

web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app id="WebApp_ID" version="2.4" xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">
<display-name>ColorSelection</display-name>
<servlet>
<servlet-name>ColorSelection</servlet-name>
<servlet-class>ColorSelection</servlet-class>
</servlet>
<servlet>
<servlet-name>GetColor</servlet-name>
<servlet-class>GetColor</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>ColorSelection</servlet-name>
<url-pattern>/ColorSelection</url-pattern>
</servlet-mapping>
<servlet-mapping>
<servlet-name>GetColor</servlet-name>
<url-pattern>/GetColor</url-pattern>
</servlet-mapping>
</web-app>

Output :

When you will execute the above example you will get the following outputs :

This is the first page where a color is to be selected.