Java by API/javax.servlet/ServletRequest

ServletRequest: getRemoteHost()

   <source lang="java">

import java.io.IOException; import java.io.PrintWriter; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; public class ExportRestriction extends HttpServlet {

 public void doGet(HttpServletRequest req, HttpServletResponse res) throws ServletException,
     IOException {
   res.setContentType("text/html");
   PrintWriter out = res.getWriter();
   // Get the client"s hostname
   String remoteHost = req.getRemoteHost();
   // See if the client is allowed
   if (!isHostAllowed(remoteHost)) {
     out.println("Access <BLINK>denied</BLINK>");
   } else {
     out.println("Access granted");
     // Display download links, etc...
   }
 }
 // Disallow hosts ending with .ru
 private boolean isHostAllowed(String host) {
   return (!host.endsWith(".ru"));
 }

}

      </source>
   
  
 
  

ServletRequest: getScheme()

   <source lang="java">

import java.io.IOException; import java.io.PrintWriter; import java.security.cert.X509Certificate; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; public class X509Snoop extends HttpServlet {

 public void doGet(HttpServletRequest req, HttpServletResponse res) throws ServletException,
     IOException {
   res.setContentType("text/plain");
   PrintWriter out = res.getWriter();
   X509Certificate[] certs = (X509Certificate[]) req
       .getAttribute("javax.servlet.request.X509Certificate");
   if (certs != null) {
     for (int i = 0; i < certs.length; i++) {
       out.println("Client Certificate [" + i + "] = " + certs[i].toString());
     }
   } else {
     if ("https".equals(req.getScheme())) {
       out.println("This was an HTTPS request, " + "but no client certificate is available");
     } else {
       out.println("This was not an HTTPS request, " + "so no client certificate is available");
     }
   }
 }

}

      </source>
   
  
 
  

ServletRequest: getServerName()

   <source lang="java">

import java.io.IOException; import java.io.PrintWriter; import java.net.InetAddress; import java.net.UnknownHostException; import javax.servlet.GenericServlet; import javax.servlet.ServletException; import javax.servlet.ServletRequest; import javax.servlet.ServletResponse; public class GetKey extends GenericServlet {

 public void service(ServletRequest req, ServletResponse res) throws ServletException, IOException {
   res.setContentType("text/plain");
   PrintWriter out = res.getWriter();
   String key = getInitParameter("key");
   String host = req.getServerName();
   int port = req.getServerPort();
   if (!keyFitsServer(key, host, port)) {
     out.println("Pirated!");
   } else {
     out.println("Valid");
   }
 }
 private boolean keyFitsServer(String key, String host, int port) {
   return true;
 }

}

      </source>
   
  
 
  

ServletRequest.getServerPort()

   <source lang="java">

import java.io.IOException; import java.io.PrintWriter; import java.net.InetAddress; import java.net.UnknownHostException; import javax.servlet.GenericServlet; import javax.servlet.ServletException; import javax.servlet.ServletRequest; import javax.servlet.ServletResponse; public class GetKey extends GenericServlet {

 public void service(ServletRequest req, ServletResponse res) throws ServletException, IOException {
   res.setContentType("text/plain");
   PrintWriter out = res.getWriter();
   String key = getInitParameter("key");
   String host = req.getServerName();
   int port = req.getServerPort();
   if (!keyFitsServer(key, host, port)) {
     out.println("Pirated!");
   } else {
     out.println("Valid");
   }
 }
 private boolean keyFitsServer(String key, String host, int port) {
   return true;
 }

}

      </source>