444517 - Ensure WebSocketUpgradeFilter is always first in filter chain

* Using Servlet 3.1's ServletContext.addFilter() mechanisms with its
    FilterRegistration to encourage the WebSocketUpgradeFilter to be
    first in the filter chain.
    Note: this is possible, but can be overridden by another call
    to the same ServletContext.addFilter() using the same techniques
    to put something in front of the WebSocketUpgradeFilter.

jetty-websocket/javax-websocket-server-impl/src/main/java/org/eclipse/jetty/websocket/jsr356/server/deploy/WebSocketServerContainerInitializer.java

@@ -45,15 +45,16 @@ public class WebSocketServerContainerInitializer implements ServletContainerInit
     public static final String ENABLE_KEY = "org.eclipse.jetty.websocket.jsr356";
     private static final Logger LOG = Log.getLogger(WebSocketServerContainerInitializer.class);
 
-
+    /**
+     * Jetty Native approach.
+     * <p>
+     * Note: this will add the Upgrade filter to the existing list, with no regard for order.  It will just be tacked onto the end of the list.
+     */
     public static ServerContainer configureContext(ServletContextHandler context)
     {
         // Create Filter
         WebSocketUpgradeFilter filter = WebSocketUpgradeFilter.configureContext(context);
 
-        // Store reference to the WebSocketUpgradeFilter
-        context.setAttribute(WebSocketUpgradeFilter.class.getName(),filter);
-
         // Create the Jetty ServerContainer implementation
         ServerContainer jettyContainer = new ServerContainer(filter,filter.getFactory(),context.getServer().getThreadPool());
         context.addBean(jettyContainer);
@@ -64,6 +65,26 @@ public class WebSocketServerContainerInitializer implements ServletContainerInit
         return jettyContainer;
     }
 
+    /**
+     * Servlet 3.1 approach.
+     * <p>
+     * This will use Servlet 3.1 techniques on the {@link ServletContext} to add a filter at the start of the filter chain.
+     */
+    public static ServerContainer configureContext(ServletContext context, ServletContextHandler jettyContext)
+    {
+        // Create Filter
+        WebSocketUpgradeFilter filter = WebSocketUpgradeFilter.configureContext(context);
+
+        // Create the Jetty ServerContainer implementation
+        ServerContainer jettyContainer = new ServerContainer(filter,filter.getFactory(),jettyContext.getServer().getThreadPool());
+        jettyContext.addBean(jettyContainer);
+
+        // Store a reference to the ServerContainer per javax.websocket spec 1.0 final section 6.4 Programmatic Server Deployment
+        context.setAttribute(javax.websocket.server.ServerContainer.class.getName(),jettyContainer);
+
+        return jettyContainer;
+    }
+
     @Override
     public void onStartup(Set<Class<?>> c, ServletContext context) throws ServletException
     {
@@ -111,7 +132,7 @@ public class WebSocketServerContainerInitializer implements ServletContainerInit
         ServletContextHandler jettyContext = (ServletContextHandler)handler;
 
         // Create the Jetty ServerContainer implementation
-        ServerContainer jettyContainer = configureContext(jettyContext);
+        ServerContainer jettyContainer = configureContext(context, jettyContext);
 
         // Store a reference to the ServerContainer per javax.websocket spec 1.0 final section 6.4 Programmatic Server Deployment
         context.setAttribute(javax.websocket.server.ServerContainer.class.getName(),jettyContainer);

jetty-websocket/websocket-server/src/main/java/org/eclipse/jetty/websocket/server/WebSocketUpgradeFilter.java

@@ -20,10 +20,13 @@ package org.eclipse.jetty.websocket.server;
 
 import java.io.IOException;
 import java.util.EnumSet;
+
 import javax.servlet.DispatcherType;
 import javax.servlet.Filter;
 import javax.servlet.FilterChain;
 import javax.servlet.FilterConfig;
+import javax.servlet.FilterRegistration;
+import javax.servlet.ServletContext;
 import javax.servlet.ServletException;
 import javax.servlet.ServletRequest;
 import javax.servlet.ServletResponse;
@@ -58,16 +61,48 @@ public class WebSocketUpgradeFilter extends ContainerLifeCycle implements Filter
     public static WebSocketUpgradeFilter configureContext(ServletContextHandler context)
     {
         WebSocketPolicy policy = new WebSocketPolicy(WebSocketBehavior.SERVER);
-
         WebSocketUpgradeFilter filter = new WebSocketUpgradeFilter(policy);
-        FilterHolder fholder = new FilterHolder(filter);
+
-        fholder.setName("Jetty_WebSocketUpgradeFilter");
+        String name = "Jetty_WebSocketUpgradeFilter";
-        fholder.setDisplayName("WebSocket Upgrade Filter");
         String pathSpec = "/*";
-        context.addFilter(fholder,pathSpec,EnumSet.of(DispatcherType.REQUEST));
+        EnumSet<DispatcherType> dispatcherTypes = EnumSet.of(DispatcherType.REQUEST);
+
+        FilterHolder fholder = new FilterHolder(filter);
+        fholder.setName(name);
+        context.addFilter(fholder,pathSpec,dispatcherTypes);
 
         if (LOG.isDebugEnabled())
-            LOG.debug("Adding {} mapped to {} to {}",filter,pathSpec,context);
+        {
+            LOG.debug("Adding [{}] {} mapped to {} to {}",name,filter,pathSpec,context);
+        }
+
+        // Store reference to the WebSocketUpgradeFilter
+        context.setAttribute(WebSocketUpgradeFilter.class.getName(),filter);
+
+        return filter;
+    }
+    
+    public static WebSocketUpgradeFilter configureContext(ServletContext context)
+    {
+        WebSocketPolicy policy = new WebSocketPolicy(WebSocketBehavior.SERVER);
+        WebSocketUpgradeFilter filter = new WebSocketUpgradeFilter(policy);
+
+        String name = "Jetty_Dynamic_WebSocketUpgradeFilter";
+        String pathSpec = "/*";
+        EnumSet<DispatcherType> dispatcherTypes = EnumSet.of(DispatcherType.REQUEST);
+        boolean isMatchAfter = false;
+        String urlPatterns[] =
+        {
+            pathSpec
+        };
+
+        FilterRegistration.Dynamic dyn = context.addFilter(name,filter);
+        dyn.addMappingForUrlPatterns(dispatcherTypes,isMatchAfter,urlPatterns);
+
+        if (LOG.isDebugEnabled())
+        {
+            LOG.debug("Adding [{}] {} mapped to {} to {}",name,filter,pathSpec,context);
+        }
 
         // Store reference to the WebSocketUpgradeFilter
         context.setAttribute(WebSocketUpgradeFilter.class.getName(),filter);