- Servlets run on a single process using threads
- Overhead of additional requests are small as it run on single process
- Servlets requires java programming skills
- JSP and servlets enables to develop modular ,maintainable ,scalable and portable applications
- Servlets run on a web containter or servlet egine
- Servlets can generate HTML response object
- Servlets are compiled into byte code.Servlets are java class file.On requests this byte codes are loaded into the memory
- Serlets talk to the client using web server
- Client request first go to the web server and webserver re-direct the requests to the container . Containter calls the generic servlet interface which calls HTTPServlet class and My Servlet class
- The response from Servlet again go back to the container and from there to web server and finally to the browser
- Most of the containter implementations are in java
- Servlet container instatiate the objects that encapsulate request or response .
- Servlet containter do initialization,processing of the request and response,unloading and finalization of servlets
- Container creates ServletContext object through which the servlet can log events ,set and store attributes at application or session level and grab file paths.
package
view;
import
java.io.IOException;
import
java.io.PrintWriter;
import
javax.servlet.*;
import
javax.servlet.annotation.WebServlet;
import
javax.servlet.http.*;
@WebServlet(name
= "Servlet1", urlPatterns = { "/servlet1" })
public
class Servlet1 extends HttpServlet {
private static final String CONTENT_TYPE =
"text/html; charset=windows-1252";
public void init(ServletConfig config)
throws ServletException {
// Initialize resources
super.init(config);
}
public void doGet(HttpServletRequest
request, HttpServletResponse response) throws ServletException, IOException {
response.setContentType(CONTENT_TYPE);
PrintWriter out = response.getWriter();
out.println("<html>");
out.println("<head><title>Servlet1</title></head>");
out.println("<body>");
out.println("<p>The servlet
has received a GET. This is the reply.</p>");
out.println("</body></html>");
out.close();
}
public void doPost(HttpServletRequest
request, HttpServletResponse response) throws ServletException, IOException {
doGet(request, response);
}
public void destroy() {
//Clean up resources
}
}
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