Added an example of embeded Jetty using hashed session and servlets. (#1107)

Signed-off-by: Luis Daniel <lalducin@nearsoft.com>

examples/embedded/src/main/java/org/eclipse/jetty/embedded/HelloSessionServlet.java

@@ -0,0 +1,52 @@
+//
+//  ========================================================================
+//  Copyright (c) 1995-2016 Mort Bay Consulting Pty. Ltd.
+//  ------------------------------------------------------------------------
+//  All rights reserved. This program and the accompanying materials
+//  are made available under the terms of the Eclipse Public License v1.0
+//  and Apache License v2.0 which accompanies this distribution.
+//
+//      The Eclipse Public License is available at
+//      http://www.eclipse.org/legal/epl-v10.html
+//
+//      The Apache License v2.0 is available at
+//      http://www.opensource.org/licenses/apache2.0.php
+//
+//  You may elect to redistribute this code under either of these licenses.
+//  ========================================================================
+//
+
+package org.eclipse.jetty.embedded;
+
+import org.eclipse.jetty.server.session.HashedSession;
+
+import java.io.IOException;
+
+import javax.servlet.ServletException;
+import javax.servlet.http.HttpServlet;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+
+public class HelloSessionServlet extends HttpServlet
+{
+    private String greeting;
+
+    public HelloSessionServlet() {}
+
+    @Override
+    protected void doGet( HttpServletRequest request,
+                          HttpServletResponse response ) throws ServletException,
+            IOException
+    {
+        HashedSession session = (HashedSession)request.getSession();
+        if((greeting = (String)session.getAttribute("greeting")) == null) {
+            greeting = "Hello";
+        }
+        response.setContentType("text/html");
+        response.setStatus(HttpServletResponse.SC_OK);
+        response.getWriter().println(
+                "<h1>" + greeting + " from HelloSessionServlet</h1>");
+    }
+
+}
+

examples/embedded/src/main/java/org/eclipse/jetty/embedded/OneServletContextWithSession.java

@@ -0,0 +1,64 @@
+//
+//  ========================================================================
+//  Copyright (c) 1995-2016 Mort Bay Consulting Pty. Ltd.
+//  ------------------------------------------------------------------------
+//  All rights reserved. This program and the accompanying materials
+//  are made available under the terms of the Eclipse Public License v1.0
+//  and Apache License v2.0 which accompanies this distribution.
+//
+//      The Eclipse Public License is available at
+//      http://www.eclipse.org/legal/epl-v10.html
+//
+//      The Apache License v2.0 is available at
+//      http://www.opensource.org/licenses/apache2.0.php
+//
+//  You may elect to redistribute this code under either of these licenses.
+//  ========================================================================
+//
+
+package org.eclipse.jetty.embedded;
+
+import org.eclipse.jetty.server.Server;
+import org.eclipse.jetty.server.session.AbstractSessionIdManager;
+import org.eclipse.jetty.server.session.HashSessionIdManager;
+import org.eclipse.jetty.server.session.HashSessionManager;
+import org.eclipse.jetty.server.session.SessionHandler;
+import org.eclipse.jetty.servlet.ServletContextHandler;
+
+
+public class OneServletContextWithSession
+{
+    public static void main(String[] args) throws Exception
+    {
+        Server server = new Server(8080);
+
+        SessionHandler handler = new SessionHandler();
+        handler.setServer(server);
+
+        HashSessionManager manager = new HashSessionManager();
+        handler.setSessionManager(manager);
+
+        AbstractSessionIdManager idManager = new HashSessionIdManager();
+        manager.setSessionIdManager(idManager);
+        server.setSessionIdManager(idManager);
+
+        ServletContextHandler context = new ServletContextHandler(
+                ServletContextHandler.SESSIONS);
+        context.setContextPath("/");
+        context.setResourceBase(System.getProperty("java.io.tmpdir"));
+        server.setHandler(context);
+
+        //Servlet to store a different greeting in the session
+        //Can be accessed using http://localhost:8080/store
+        context.addServlet(StoreInSessionServlet.class, "/store/*");
+
+        //Servlet to read the greeting stored in the session, if you have not visited the
+        //StoreInSessionServlet a default greeting is shown, after visiting you will see
+        //a different greeting.
+        //Can be accessed using http://localhost:8080/hello
+        context.addServlet(HelloSessionServlet.class, "/");
+
+        server.start();
+        server.join();
+    }
+}

examples/embedded/src/main/java/org/eclipse/jetty/embedded/StoreInSessionServlet.java

@@ -0,0 +1,47 @@
+//
+//  ========================================================================
+//  Copyright (c) 1995-2016 Mort Bay Consulting Pty. Ltd.
+//  ------------------------------------------------------------------------
+//  All rights reserved. This program and the accompanying materials
+//  are made available under the terms of the Eclipse Public License v1.0
+//  and Apache License v2.0 which accompanies this distribution.
+//
+//      The Eclipse Public License is available at
+//      http://www.eclipse.org/legal/epl-v10.html
+//
+//      The Apache License v2.0 is available at
+//      http://www.opensource.org/licenses/apache2.0.php
+//
+//  You may elect to redistribute this code under either of these licenses.
+//  ========================================================================
+//
+
+package org.eclipse.jetty.embedded;
+
+import org.eclipse.jetty.server.session.HashedSession;
+
+import java.io.IOException;
+
+import javax.servlet.ServletException;
+import javax.servlet.http.HttpServlet;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+
+public class StoreInSessionServlet extends HttpServlet
+{
+    public StoreInSessionServlet() {}
+
+    @Override
+    protected void doGet(HttpServletRequest request,
+                         HttpServletResponse response ) throws ServletException,
+                                                        IOException
+    {
+        HashedSession session = (HashedSession)request.getSession();
+        session.setAttribute("greeting", "New Hello");
+
+        response.setContentType("text/html");
+        response.setStatus(HttpServletResponse.SC_OK);
+        response.getWriter().println(
+                "<h1>Value 'New Hello' stored in session.</h1>");
+    }
+}