Example 5:
Handling Http Request &
Responses(doGet)
·
This example uses doGet method
·
Create following files in a folder (Please check
next slide for code)
o HTMLFile
index.html Contains html that allows user to enter details
o Java
File HTTPReqResPost.java Contains logic to get the params details
o DD
web.xml Contains deployment details. Deployment Descriptor
·
Compile the Java File as you did in earlier
example
·
Create below structure with files that you
created above
o Folder
"HTTPReqResGet" contains
o I__"WEB-INF"
Folder and index.html
o I__"WEB-INF"
Folder contains "classes" Folder and web.xml File
o I__"classes"
Folder contains "HTTPReqResGet.class" File
·
Deploy the HTTPReqResGet folder inside webapps
folder of Tomcat
·
Bounce the Server
·
Send request using
"http://localhost:8550/HTTPReqResGet/index.html"
index.html
<html>
<body>
<center>
<h1
align="center">Welcome to Student Registration Page...</h1>
<form
name=”StudentForm” action=”StudentGet.do”>
<table>
<tr>
<td><B>Name
of Student : </td>
<td><input
type=textbox name="StudentNameParam" size="25"
value=""></td>
</tr>
<tr>
<td><B>Registration
# </td>
<td><input
type=textbox name="RollNumberParam" size="25"
value=""></td>
</tr>
<tr>
<td><B>Father's
Name : </td>
<td><input
type=textbox name="FatherName" size="25"
value=""></td>
</tr>
<tr>
<td><B>Gender :
<input type="radio" name="gender"
value="male">Male <input
type="radio" name="gender” value=”female”> </td>
</tr>
</table> <input type=submit value="Submir>
</form>
</body>
</html>
·
HTTPReqResGet.java:
This prepares the response as HTML file that displays value of request
parameters that are provided in servlet.
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class HTTPReqResGet
extends HttpServlet {
public void
doGet(HttpServletRequest request, HttpServletResponse response) throws
ServletException, IOException {
String name =
request.getParameter("StudentNameParam");
response.setContentType("text/html");
PrintWriter pw =
response.getWriter();
pw.printIn("<B>Entered
Student name is : ");
pw.println(name);
pw.close();
}
}
·
web.xml
o <servlet>
tag maps your servlet class with internal name
o <servlet-mapping>
tag maps internal name with url-pattern that your invoke
<web-app
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/web-app_2_4.xsd"
version="2.4">
<servlet>
<servlet-name>getservletget</servlet-name>
<servlet-class>HTTPReqResGet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>getservletget</servlet-name>
<url-pattern>/StudentGet.do</url-pattern>
</servlet-mapping>
</web-app>
