postingan ini adalah lanjutan yang sebelumnya tentang Servlet Filter, kali ini saya akan sharing tentang program Java Servlet Context dan Listener. Langsung aja kita buat programnya
1.index.html
2. LoginServlet.java
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
/**
*
* @author Ilyas A. Jaelani
*/
public class LoginServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
private final String userID = "admin";
private final String password = "123";
/**
* Processes requests for both HTTP
* GET and
* POST methods.
*
* @param request servlet request
* @param response servlet response
* @throws ServletException if a servlet-specific error occurs
* @throws IOException if an I/O error occurs
*/
protected void processRequest(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html;charset=UTF-8");
PrintWriter out = response.getWriter();
try {
/* TODO output your page here. You may use following sample code. */
out.println("");
out.println("");
out.println("");
out.println("Servlet LoginServlet ");
out.println("");
out.println("");
out.println("
Servlet LoginServlet at " + request.getContextPath() + "
");
out.println("");
out.println("");
} finally {
out.close();
}
}
//
/**
* Handles the HTTP
* GET method.
*
* @param request servlet request
* @param response servlet response
* @throws ServletException if a servlet-specific error occurs
* @throws IOException if an I/O error occurs
*/
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
processRequest(request, response);
}
/**
* Handles the HTTP
* POST method.
*
* @param request servlet request
* @param response servlet response
* @throws ServletException if a servlet-specific error occurs
* @throws IOException if an I/O error occurs
*/
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
// processRequest(request, response);
String user = request.getParameter("user");
String pwd = request.getParameter("pwd");
if (userID.equals(user) && password.equals(pwd)) {
HttpSession session = request.getSession();
session.setAttribute("user", "Pankaj");
//setting session to expiry in 30 mins
session.setMaxInactiveInterval(30 * 60);
Cookie userName = new Cookie("user", user);
userName.setMaxAge(30 * 60);
response.addCookie(userName);
response.sendRedirect("LoginSuccess.jsp");
} else {
RequestDispatcher rd = getServletContext().getRequestDispatcher("/index.html");
PrintWriter out = response.getWriter();
out.println("Either user name or password is wrong.");
rd.include(request, response);
}
}
/**
* Returns a short description of the servlet.
*
* @return a String containing servlet description
*/
@Override
public String getServletInfo() {
return "Short description";
}//
}
3. LoginSuccess.jsp
JSP Page
<%
//allow access only if session exists
String user = (String) session.getAttribute("user");
String userName = null;
String sessionID = null;
Cookie[] cookies = request.getCookies();
if (cookies != null) {
for (Cookie cookie : cookies) {
if (cookie.getName().equals("user")) {
userName = cookie.getValue();
}
if (cookie.getName().equals("JSESSIONID")) {
sessionID = cookie.getValue();
}
}
}
%>
Hi <%=userName%>, Login successful. Your Session ID=<%=sessionID%>
User=<%=user%>
Checkout Page
4. CheckoutPage.jsp
JSP Page
<%
String userName = null;
String sessionID = null;
Cookie[] cookies = request.getCookies();
if (cookies != null) {
for (Cookie cookie : cookies) {
if (cookie.getName().equals("user")) {
userName = cookie.getValue();
}
}
}
%>
Hi <%=userName%>, do the checkout.
5. LogoutServlet.java
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
/**
*
* @author Ilyas A. Jaelani
*/
public class LogoutServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
/**
* Processes requests for both HTTP
* GET and
* POST methods.
*
* @param request servlet request
* @param response servlet response
* @throws ServletException if a servlet-specific error occurs
* @throws IOException if an I/O error occurs
*/
protected void processRequest(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html;charset=UTF-8");
PrintWriter out = response.getWriter();
try {
/* TODO output your page here. You may use following sample code. */
out.println("");
out.println("");
out.println("");
out.println("Servlet LogoutServlet ");
out.println("");
out.println("");
out.println("
Servlet LogoutServlet at " + request.getContextPath() + "
");
out.println("");
out.println("");
} finally {
out.close();
}
}
//
/**
* Handles the HTTP
* GET method.
*
* @param request servlet request
* @param response servlet response
* @throws ServletException if a servlet-specific error occurs
* @throws IOException if an I/O error occurs
*/
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
processRequest(request, response);
}
/**
* Handles the HTTP
* POST method.
*
* @param request servlet request
* @param response servlet response
* @throws ServletException if a servlet-specific error occurs
* @throws IOException if an I/O error occurs
*/
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
// processRequest(request, response);
response.setContentType("text/html");
Cookie[] cookies = request.getCookies();
if (cookies != null) {
for (Cookie cookie : cookies) {
if (cookie.getName().equals("JSESSIONID")) {
System.out.println("JSESSIONID=" + cookie.getValue());
break;
}
}
}
//invalidate the session if exists
HttpSession session = request.getSession(false);
System.out.println("User=" + session.getAttribute("user"));
if (session != null) {
session.invalidate();
}
response.sendRedirect("index.html");
}
/**
* Returns a short description of the servlet.
*
* @return a String containing servlet description
*/
@Override
public String getServletInfo() {
return "Short description";
}//
}
6.RequestLoggingFilter.java
import java.io.IOException;
import java.io.PrintStream;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.util.Enumeration;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
/**
*
* @author Ilyas A. Jaelani
*/
public class RequestLoggingFilter implements Filter {
private static final boolean debug = true;
private FilterConfig filterConfig = null;
public RequestLoggingFilter() {
}
private void doBeforeProcessing(ServletRequest request, ServletResponse response)
throws IOException, ServletException {
if (debug) {
log("RequestLoggingFilter:DoBeforeProcessing");
}
HttpServletRequest req = (HttpServletRequest) request;
Enumeration params = req.getParameterNames();
while (params.hasMoreElements()) {
String name = params.nextElement();
String value = request.getParameter(name);
log(req.getRemoteAddr() + "::Request Params::{" + name + "=" + value + "}");
}
Cookie[] cookies = req.getCookies();
if (cookies != null) {
for (Cookie cookie : cookies) {
log(req.getRemoteAddr() + "::Cookie::{" + cookie.getName() + "," + cookie.getValue() + "}");
}
}
}
private void doAfterProcessing(ServletRequest request, ServletResponse response)
throws IOException, ServletException {
if (debug) {
log("RequestLoggingFilter:DoAfterProcessing");
}
}
/**
* Processes requests for both HTTP
* GET and
* POST methods.
*
* @param request servlet request
* @param response servlet response
* @throws ServletException if a servlet-specific error occurs
* @throws IOException if an I/O error occurs
*/
public void doFilter(ServletRequest request, ServletResponse response,
FilterChain chain)
throws IOException, ServletException {
if (debug) {
log("RequestLoggingFilter:doFilter()");
}
doBeforeProcessing(request, response);
Throwable problem = null;
try {
chain.doFilter(request, response);
} catch (Throwable t) {
// If an exception is thrown somewhere down the filter chain,
// we still want to execute our after processing, and then
// rethrow the problem after that.
problem = t;
t.printStackTrace();
}
doAfterProcessing(request, response);
if (problem != null) {
if (problem instanceof ServletException) {
throw (ServletException) problem;
}
if (problem instanceof IOException) {
throw (IOException) problem;
}
sendProcessingError(problem, response);
}
}
public FilterConfig getFilterConfig() {
return (this.filterConfig);
}
public void setFilterConfig(FilterConfig filterConfig) {
this.filterConfig = filterConfig;
}
public void destroy() {
}
public void init(FilterConfig filterConfig) {
this.filterConfig = filterConfig;
if (filterConfig != null) {
if (debug) {
log("RequestLoggingFilter:Initializing filter");
}
}
}
@Override
public String toString() {
if (filterConfig == null) {
return ("RequestLoggingFilter()");
}
StringBuffer sb = new StringBuffer("RequestLoggingFilter(");
sb.append(filterConfig);
sb.append(")");
return (sb.toString());
}
private void sendProcessingError(Throwable t, ServletResponse response) {
String stackTrace = getStackTrace(t);
if (stackTrace != null && !stackTrace.equals("")) {
try {
response.setContentType("text/html");
PrintStream ps = new PrintStream(response.getOutputStream());
PrintWriter pw = new PrintWriter(ps);
pw.print("\n\nError \n\n\n");
//NOI18N
// PENDING! Localize this for next official release
pw.print("
The resource did not process correctly
\n\n");
pw.print(stackTrace);
pw.print("
\n"); //NOI18N
pw.close();
ps.close();
response.getOutputStream().close();
} catch (Exception ex) {
}
} else {
try {
PrintStream ps = new PrintStream(response.getOutputStream());
t.printStackTrace(ps);
ps.close();
response.getOutputStream().close();
} catch (Exception ex) {
}
}
}
public static String getStackTrace(Throwable t) {
String stackTrace = null;
try {
StringWriter sw = new StringWriter();
PrintWriter pw = new PrintWriter(sw);
t.printStackTrace(pw);
pw.close();
sw.close();
stackTrace = sw.getBuffer().toString();
} catch (Exception ex) {
}
return stackTrace;
}
public void log(String msg) {
filterConfig.getServletContext().log(msg);
}
}
7. AuthenticationFilter.java
import java.io.IOException;
import java.io.PrintStream;
import java.io.PrintWriter;
import java.io.StringWriter;
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;
/**
*
* @author Ilyas A. Jaelani
*/
public class AuthenticationFilter implements Filter {
private static final boolean debug = true;
private FilterConfig filterConfig = null;
public AuthenticationFilter() {
}
private void doBeforeProcessing(ServletRequest request, ServletResponse response)
throws IOException, ServletException {
if (debug) {
log("RequestLoggingFilter:DoBeforeProcessing");
}
}
private void doAfterProcessing(ServletRequest request, ServletResponse response)
throws IOException, ServletException {
if (debug) {
log("RequestLoggingFilter:DoAfterProcessing");
}
}
/**
* Processes requests for both HTTP
* GET and
* POST methods.
*
* @param request servlet request
* @param response servlet response
* @throws ServletException if a servlet-specific error occurs
* @throws IOException if an I/O error occurs
*/
public void doFilter(ServletRequest request, ServletResponse response,
FilterChain chain)
throws IOException, ServletException {
if (debug) {
log("AuthenticationFilter:doFilter()");
}
doBeforeProcessing(request, response);
Throwable problem = null;
try {
HttpServletRequest req = (HttpServletRequest) request;
HttpServletResponse res = (HttpServletResponse) response;
String uri = req.getRequestURI();
log("Requested Resource::" + uri);
HttpSession session = req.getSession(false);
if (session == null && !(uri.endsWith("html") || uri.endsWith("LoginServlet"))) {
log("Unauthorized access request");
res.sendRedirect("index.html");
} else {
// pass the request along the filter chain
chain.doFilter(request, response);
}
} catch (Throwable t) {
// If an exception is thrown somewhere down the filter chain,
// we still want to execute our after processing, and then
// rethrow the problem after that.
problem = t;
t.printStackTrace();
}
doAfterProcessing(request, response);
// If there was a problem, we want to rethrow it if it is
// a known type, otherwise log it.
if (problem != null) {
if (problem instanceof ServletException) {
throw (ServletException) problem;
}
if (problem instanceof IOException) {
throw (IOException) problem;
}
sendProcessingError(problem, response);
}
}
public FilterConfig getFilterConfig() {
return (this.filterConfig);
}
public void setFilterConfig(FilterConfig filterConfig) {
this.filterConfig = filterConfig;
}
public void destroy() {
}
public void init(FilterConfig filterConfig) {
this.filterConfig = filterConfig;
if (filterConfig != null) {
if (debug) {
log("AuthenticationFilter:Initializing filter");
}
}
}
@Override
public String toString() {
if (filterConfig == null) {
return ("AuthenticationFilter()");
}
StringBuffer sb = new StringBuffer("AuthenticationFilter(");
sb.append(filterConfig);
sb.append(")");
return (sb.toString());
}
private void sendProcessingError(Throwable t, ServletResponse response) {
String stackTrace = getStackTrace(t);
if (stackTrace != null && !stackTrace.equals("")) {
try {
response.setContentType("text/html");
PrintStream ps = new PrintStream(response.getOutputStream());
PrintWriter pw = new PrintWriter(ps);
pw.print("\n\nError \n\n\n");
//NOI18N
// PENDING! Localize this for next official release
pw.print("
The resource did not process correctly
\n\n");
pw.print(stackTrace);
pw.print("
\n"); //NOI18N
pw.close();
ps.close();
response.getOutputStream().close();
} catch (Exception ex) {
}
} else {
try {
PrintStream ps = new PrintStream(response.getOutputStream());
t.printStackTrace(ps);
ps.close();
response.getOutputStream().close();
} catch (Exception ex) {
}
}
}
public static String getStackTrace(Throwable t) {
String stackTrace = null;
try {
StringWriter sw = new StringWriter();
PrintWriter pw = new PrintWriter(sw);
t.printStackTrace(pw);
pw.close();
sw.close();
stackTrace = sw.getBuffer().toString();
} catch (Exception ex) {
}
return stackTrace;
}
public void log(String msg) {
filterConfig.getServletContext().log(msg);
}
}
source core selesai
tinggal kita run program. maka tampilan akhirnya seperti ini :
cukup sekian program Java Servlet Filter. postingan selanjutnya saya akan sharing tentang Java Servlet Context dan Listener serta Java Servlet Context dan Listener Database.
Semoga bermanfaat dan terimakasih, mohon maaf jika ada kesalahan kata :)
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