G-InfoArena: September 2014

Every project that we do, there are always some common requirement, that project must need to implement.
So one of the common requirement i want to discuss here is...

"duplicate form request submission"

In any project duplicate form request must be intercept and must be aborted, to avoid duplicate data or inconsistency.
In J2EE environment, we can achieve this functionality by using following resources-

Using Filter Class
Using Controller Class(Servlet)

Lets start creating.....

Presentation Tier Component (JSPs)

insertstudent.jsp
<%-- Document : insertstudent Author : Gaurav Pathak --%> <%@ page language="java" contentType="text/html; charset=ISO-8859-1" pageEncoding="ISO-8859-1"%> <!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>Duplicate form Request</title> </head> <body> <form action="${pageContext.request.contextPath}/StudentInsertServlet" method="post"> Studentid:<input type="text" name="id"/><br/> Studentname:<input type="text" name="name"/><br/> <input type="hidden" name="ctoken" value="${stoken}"/> <input type="submit" value="insert"/> </form> </body> </html>
success.jsp
<%-- Document : success.jsp Author : Gaurav Pathak --%> <%@ page language="java" contentType="text/html; charset=ISO-8859-1" pageEncoding="ISO-8859-1"%> <!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>Student Inserted Successfully!</title> </head> <body> <p style="color:green;"> Inserted Student: ${stdId} successfully... </p> </body> </html>
error.jsp
<%-- Document : error.jsp Author : Gaurav Pathak --%> <%@ page language="java" contentType="text/html; charset=ISO-8859-1" pageEncoding="ISO-8859-1"%> <!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>Error!</title> </head> <body> <p style="color:red;">Due to security restriction your session has been expired.please re-login....<br/> below are the possible reasons</p> <ul> <li>Browser back button pressed</li> <li>Duplicate form request</li> <li>you have pressed F5</li> </ul> </body> </html>

Controller Component (Filter)

DuplicateRequestInterceptor.class
/*** * @author:Gaurav Pathak */ import java.io.IOException; import java.util.Calendar; import javax.servlet.Filter; import javax.servlet.FilterChain; import javax.servlet.FilterConfig; import javax.servlet.ServletException; import javax.servlet.ServletRequest; import javax.servlet.ServletResponse; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.servlet.http.HttpSession; public class DuplicateRequestInterceptor implements Filter { @Override public void destroy() { // no-op } @Override public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException { System.out.println("in doFilter of DuplicateRequestInterceptor"); HttpServletRequest httpRequest = null; HttpSession session = null; String method = null; String token = null; String cToken = null; httpRequest = (HttpServletRequest) request; session = httpRequest.getSession(false); // new user if (session == null) { session = httpRequest.getSession(); } else { System.out.println("session is not null... existing user"); // existing user method = httpRequest.getMethod(); if (method.equalsIgnoreCase("post")) { cToken = request.getParameter("ctoken"); token = (String) session.getAttribute("stoken"); if (token.equals(cToken) == false) { session.invalidate(); ((HttpServletResponse) response) .sendRedirect("error.jsp"); return; } } } token = session.getId() + Calendar.getInstance().getTimeInMillis(); session.setAttribute("stoken", token); chain.doFilter(request, response); } @Override public void init(FilterConfig config) throws ServletException { // no-op } }
StudentInsertServlet.class
import java.io.IOException; import java.io.PrintWriter; import javax.servlet.RequestDispatcher; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; /** * * @author Gaurav Pathak */ public class StudentInsertServlet extends HttpServlet { protected void processRequest(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.setContentType("text/html;charset=UTF-8"); PrintWriter out = response.getWriter(); try { String id = null; RequestDispatcher rd = null; id = request.getParameter("id"); request.setAttribute("stdId", id); rd = request.getRequestDispatcher("success.jsp"); rd.forward(request, response); } finally { out.close(); } } // <editor-fold defaultstate="collapsed" desc="HttpServlet methods. Click on the + sign on the left to edit the code."> @Override protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { processRequest(request, response); } @Override protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { processRequest(request, response); } @Override public String getServletInfo() { return "Short description"; } }

Entries in Deployment Descriptor(web.xml)

web.xml
<filter> <filter-name>DuplicateRequestInterceptor </filter-name> <filter-class>DuplicateRequestInterceptor.java</filter-class> </filter> <filter-mapping> <filter-name>DuplicateRequestInterceptor</filter-name> <url-pattern>/*</url-pattern> </filter-mapping> With this configuration all requests will be intercepted by the DuplicateRequestInterceptor filter.

G-InfoArena

Wednesday, 3 September 2014

Duplicate Form Request Interceptor In JAVA

Every project that we do, there are always some common requirement, that project must need to implement.
So one of the common requirement i want to discuss here is...

Presentation Tier Component (JSPs)

Controller Component (Filter)

Entries in Deployment Descriptor(web.xml)

You have to include below code in all jsp page that are the part of your navigation, to stop duplicate form submission.

Contributors

Wednesday, 3 September 2014

Duplicate Form Request Interceptor In JAVA

Every project that we do, there are always some common requirement, that project must need to implement.So one of the common requirement i want to discuss here is...

Presentation Tier Component (JSPs)

Controller Component (Filter)

Entries in Deployment Descriptor(web.xml)

You have to include below code in all jsp page that are the part of your navigation, to stop duplicate form submission.

Every project that we do, there are always some common requirement, that project must need to implement.
So one of the common requirement i want to discuss here is...