Example 1: Servlet that sends Date-Time
Let
us try these simple hands on. Get the date and time from server.
- Create following files in a folder (Please check next slide for code)
- Java File TimeServlet.java web.xml Contains logic to display date
- DD web.xml Contains deployment details. Deployment Descriptor
- Compile the Java File using below command.
- Please change the path appropriate to your folder structure
- D:\Tomcat>javac -cp "C: \Program Files\Apache Software Foundation \Tomcat 6.0\lib\servlet-api jar" TimeServlet.java
- Create below structure with files that you created above
- Folder "TimeServlet" contains "WEB-INF" Folder
- I__"WEB-INF" Folder contains "classes" Folder and web.xml File
- I__"classes" Folder contains "TimeServlet.class" File
- Deploy the TimeServlet folder inside webapps folder of Tomcat
- Bounce the Server
- Send request using "http://localhost:8550/TimeServlet/myTimeServIer
TimeServlet.java:
This prepares the response as HTML file that displays date and time on server.
For every refresh, you can see change in time
import java.io.*;
import java.util.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class TimeServlet
extends HttpServlet {
public void
doGet(HttpServletRequest request, HttpServletResponse response) throws
IOException,
ServletException
{
response.setContentType("text/htmI");
PrintWriter
out = response.getWriter();
outprintln("<html>");
out.println("<head>");
out.
println("<title> FirstExample! </title>");
out.println("</head>");
out.
println("<body>");
out.
println("<h1>This is our first servlet example!</h1>");
out.
println("Time : "+(new Date()).toLocaleString());
outprintln("</body>");
out.
println("</html>");
}
}
web.xml
- <servlet> tag maps your servlet class with internal name
- <servlet-mapping> tag maps internal name with url-pattern that your invoke
<web-app>
<servlet>
<servlet-name>firstexample</servlet-name>
<servlet-class>TimeServlet</servlet-class>
</servlet>
<servlet-mapping>
<serviet-name>firstexample</servlet-name>
<url-pattern>/myTimeServlet</url-pattern>
</servlet-mapping>
</web-app>
- Output: http://localhost:8550/TimeServlet/myTimeServlet
- localhost Machine where tomcat is installed
- 8550 This is the port which is mentioned during installation
- TimeSevlet Application name (Folder name)
- myTimeServlet url-pattern provide for servlet in web.xml
Re-submit the same url again :
you can see the change in time. That shows the response is dynamic and response
is server time.
