Aqui se presenta el código de los servlet que determina si el usuario es bloqueado,
en este caso los usuarios que no son administradores(se los bloquea)
package DAW;
import java.io.*;
import java.net.*;
import javax.servlet.*;
import javax.servlet.http.*;
/**
*
* @author estudiante
*/
public class controller2 extends HttpServlet{
/** Creates a new instance of NewClass */
protected void processRequest(HttpServletRequest req, HttpServletResponse res) throws ServletException, IOException{
String usuario=req.getParameter(«usuario»);
String password=req.getParameter(«pasword»);
res.setContentType(«text/html; charset=UTF-8»);
//PrintWriter out = res.getWriter();
if(usuario.equalsIgnoreCase(«admin») && password.equalsIgnoreCase(«admin»)){
String nextJSP = «/pagina4.jsp»;
RequestDispatcher rd = getServletContext().getRequestDispatcher(nextJSP);
rd.forward(req, res);
}else
res.sendError(401,»Usted esta bloqueado»);
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
{
processRequest(request, response);
}
/** Handles the HTTP <code>POST</code> method.
* @param request servlet request
* @param response servlet response
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
{
processRequest(request, response);
}
/** Returns a short description of the servlet.
*/
public String getServletInfo() {
return «Short description»;
}
}
Aqui se presenta el código de los servlet que determina si el usuario es bloqueado,
en este caso los usuarios que no son estudiantes(se los bloquea)
package DAW;
import java.io.*;
import java.net.*;
import javax.servlet.*;
import javax.servlet.http.*;
/**
*
* @author estudiante
*/
public class controller extends HttpServlet{
/** Creates a new instance of NewClass */
protected void processRequest(HttpServletRequest req, HttpServletResponse res) throws ServletException, IOException{
String usuario=req.getParameter(«usuario»);
String password=req.getParameter(«pasword»);
res.setContentType(«text/html; charset=UTF-8»);
//PrintWriter out = res.getWriter();
if(usuario.equalsIgnoreCase(«estud») && password.equalsIgnoreCase(«estud»)){
String nextJSP = «/pagina3.jsp»;
RequestDispatcher rd = getServletContext().getRequestDispatcher(nextJSP);
rd.forward(req, res);
}else
res.sendError(401,»Usted esta bloqueado»);
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
{
processRequest(request, response);
}
/** Handles the HTTP <code>POST</code> method.
* @param request servlet request
* @param response servlet response
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
{
processRequest(request, response);
}
/** Returns a short description of the servlet.
*/
public String getServletInfo() {
return «Short description»;
}
}
Para poder vereficar el rol de estudiante se utiliza el siguiente filtro:
package DAW;
import java.io.*;
import java.net.*;
import java.util.*;
import java.text.*;
import javax.servlet.*;
import javax.servlet.http.*;
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;
/**
*
* @author Daniel
*/
public class FilterLogin2 implements Filter {
// The filter configuration object we are associated with. If
// this value is null, this filter instance is not currently
// configured.
private FilterConfig filterConfig = null;
public FilterLogin2() {
}
private void doBeforeProcessing(ServletRequest request, ServletResponse response)
throws IOException, ServletException {
if (debug) log(«FilterLogin2:DoBeforeProcessing»);
//
// Write code here to process the request and/or response before
// the rest of the filter chain is invoked.
//
//
// For example, a logging filter might log items on the request object,
// such as the parameters.
//
/*
for (Enumeration en = request.getParameterNames(); en.hasMoreElements(); ) {
String name = (String)en.nextElement();
String values[] = request.getParameterValues(name);
int n = values.length;
StringBuffer buf = new StringBuffer();
buf.append(name);
buf.append(«=»);
for(int i=0; i < n; i++) {
buf.append(values[i]);
if (i < n-1)
buf.append(«,»);
}
log(buf.toString());
}
*/
}
private void doAfterProcessing(ServletRequest request, ServletResponse response) throws IOException, ServletException {
if (debug) log(«FilterLogin2:DoAfterProcessing»);
//
// Write code here to process the request and/or response after
// the rest of the filter chain is invoked.
//
//
// For example, a logging filter might log the attributes on the
// request object after the request has been processed.
//
/*
for (Enumeration en = request.getAttributeNames(); en.hasMoreElements(); ) {
String name = (String)en.nextElement();
Object value = request.getAttribute(name);
log(«attribute: » + name + «=» + value.toString());
}
*/
//
//
// For example, a filter might append something to the response.
//
/*
PrintWriter respOut = new PrintWriter(response.getWriter());
respOut.println(«<P><B>This has been appended by an intrusive filter.</B>»);
*/
}
/**
*
* @param request The servlet request we are processing
* @param response The servlet response we are creating
* @param chain The filter chain we are processing
*
* @exception IOException if an input/output error occurs
* @exception ServletException if a servlet error occurs
*/
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
HttpServletResponse res=(HttpServletResponse)response;
if (debug) log(«FilterLogin2:doFilter()»);
doBeforeProcessing(request, response);
Throwable problem = null;
try {
String user = request.getParameter(«usuario»);
String pass = request.getParameter(«pasword»);
if(user.equalsIgnoreCase(«admin») && pass.equalsIgnoreCase(«admin»)){
chain.doFilter(request, response);
}else
res.sendError(401,»Usted esta bloqueado»);
}
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);
}
}
/**
* Return the filter configuration object for this filter.
*/
public FilterConfig getFilterConfig() {
return (this.filterConfig);
}
/**
* Set the filter configuration object for this filter.
*
* @param filterConfig The filter configuration object
*/
public void setFilterConfig(FilterConfig filterConfig) {
this.filterConfig = filterConfig;
}
/**
* Destroy method for this filter
*
*/
public void destroy() {
}
/**
* Init method for this filter
*
*/
public void init(FilterConfig filterConfig) {
this.filterConfig = filterConfig;
if (filterConfig != null) {
if (debug) {
log(«FilterLogin2:Initializing filter»);
}
}
}
/**
* Return a String representation of this object.
*/
public String toString() {
if (filterConfig == null) return («FilterLogin2()»);
StringBuffer sb = new StringBuffer(«FilterLogin2(«);
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(«<html>\n<head>\n<title>Error</title>\n</head>\n<body>\n»); //NOI18N
// PENDING! Localize this for next official release
pw.print(«<h1>The resource did not process correctly</h1>\n<pre>\n»);
pw.print(stackTrace);
pw.print(«</pre></body>\n</html>»); //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);
}
private static final boolean debug = true;
}
Para poder vereficar el rol de administrador se utiliza el siguiente filtro:
package DAW;
import java.io.*;
import java.net.*;
import java.util.*;
import java.text.*;
import javax.servlet.*;
import javax.servlet.http.*;
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;
/**
*
* @author Daniel
*/
public class FiltroLogin implements Filter {
// The filter configuration object we are associated with. If
// this value is null, this filter instance is not currently
// configured.
private FilterConfig filterConfig = null;
public FiltroLogin() {
}
private void doBeforeProcessing(ServletRequest request, ServletResponse response)
throws IOException, ServletException {
if (debug) log(«FiltroLogin:DoBeforeProcessing»);
//
// Write code here to process the request and/or response before
// the rest of the filter chain is invoked.
//
//
// For example, a logging filter might log items on the request object,
// such as the parameters.
//
/*
for (Enumeration en = request.getParameterNames(); en.hasMoreElements(); ) {
String name = (String)en.nextElement();
String values[] = request.getParameterValues(name);
int n = values.length;
StringBuffer buf = new StringBuffer();
buf.append(name);
buf.append(«=»);
for(int i=0; i < n; i++) {
buf.append(values[i]);
if (i < n-1)
buf.append(«,»);
}
log(buf.toString());
}
*/
}
private void doAfterProcessing(ServletRequest request, ServletResponse response) throws IOException, ServletException {
if (debug) log(«FiltroLogin:DoAfterProcessing»);
//
// Write code here to process the request and/or response after
// the rest of the filter chain is invoked.
//
//
// For example, a logging filter might log the attributes on the
// request object after the request has been processed.
//
/*
for (Enumeration en = request.getAttributeNames(); en.hasMoreElements(); ) {
String name = (String)en.nextElement();
Object value = request.getAttribute(name);
log(«attribute: » + name + «=» + value.toString());
}
*/
//
//
// For example, a filter might append something to the response.
//
/*
PrintWriter respOut = new PrintWriter(response.getWriter());
respOut.println(«<P><B>This has been appended by an intrusive filter.</B>»);
*/
}
/**
*
* @param request The servlet request we are processing
* @param response The servlet response we are creating
* @param chain The filter chain we are processing
*
* @exception IOException if an input/output error occurs
* @exception ServletException if a servlet error occurs
*/
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
HttpServletResponse res=(HttpServletResponse)response;
if (debug) log(«FiltroLogin:doFilter()»);
doBeforeProcessing(request, response);
Throwable problem = null;
try {
String user = request.getParameter(«usuario»);
String pass = request.getParameter(«pasword»);
if(user.equalsIgnoreCase(«estud») && pass.equalsIgnoreCase(«estud»)){
chain.doFilter(request, response);
}else
res.sendError(401,»Su nombre de usuario» + user + » esta bloqueado para esta opcion, «);
}
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);
}
}
/**
* Return the filter configuration object for this filter.
*/
public FilterConfig getFilterConfig() {
return (this.filterConfig);
}
/**
* Set the filter configuration object for this filter.
*
* @param filterConfig The filter configuration object
*/
public void setFilterConfig(FilterConfig filterConfig) {
this.filterConfig = filterConfig;
}
/**
* Destroy method for this filter
*
*/
public void destroy() {
}
/**
* Init method for this filter
*
*/
public void init(FilterConfig filterConfig) {
this.filterConfig = filterConfig;
if (filterConfig != null) {
if (debug) {
log(«FiltroLogin:Initializing filter»);
}
}
}
/**
* Return a String representation of this object.
*/
public String toString() {
if (filterConfig == null) return («FiltroLogin()»);
StringBuffer sb = new StringBuffer(«FiltroLogin(«);
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(«<html>\n<head>\n<title>Error</title>\n</head>\n<body>\n»); //NOI18N
// PENDING! Localize this for next official release
pw.print(«<h1>The resource did not process correctly</h1>\n<pre>\n»);
pw.print(stackTrace);
pw.print(«</pre></body>\n</html>»); //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);
}
private static final boolean debug = true;
}
Aqui se muestra la codificación de la página principal index.jsp
<%@page contentType=»text/html» pageEncoding=»windows-1252″%>
<!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=windows-1252″>
<title>JSP Page</title>
</head>
<body>
<h1>Hello World!</h1>
<div id=»barra»>
<ul>
<li><a href=»Pagina2.jsp»>Concurso Estudiantil de Robótica(Sólo Estudiantes)</a></li>
<li><a href=»pagina5.jsp»>Ingesar Nuevos Productos Robóticos(Sólo Administradores)</a></li>
<li><a href=»pagina1.jsp»>Tipos de Robots(Todo público)</a></li>
</ul>
</div>
</body>
</html>
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