Fix #5746: implement 103 early hints

impl/pom.xml

@@ -29,7 +29,7 @@
    <artifactId>mojarra</artifactId>
    <packaging>jar</packaging>
 
-   <name>Mojarra ${project.version}</name>
+   <name>Mojarra ${project.version} - Impl</name>
    <description>EE4J Compatible Implementation for Jakarta Faces API</description>
 
     <url>https://github.com/eclipse-ee4j/mojarra</url>

impl/src/main/java/org/glassfish/mojarra/RIConstants.java

@@ -88,7 +88,7 @@ public class RIConstants {
 
     public static final String VIEWID_KEY_NAME = RI_PREFIX + "viewId";
 
-    public static final String PUSH_RESOURCE_URLS_KEY_NAME = RI_PREFIX + "resourceUrls";
+    public static final String EARLY_HINTS_RESOURCE_URLS_KEY_NAME = RI_PREFIX + "earlyHintsResourceUrls";
 
     /**
      * Marker used when saving the list of component adds and removes.

impl/src/main/java/org/glassfish/mojarra/context/ExternalContextImpl.java

@@ -17,7 +17,7 @@
 
 package org.glassfish.mojarra.context;
 
-import static org.glassfish.mojarra.RIConstants.PUSH_RESOURCE_URLS_KEY_NAME;
+import static org.glassfish.mojarra.RIConstants.EARLY_HINTS_RESOURCE_URLS_KEY_NAME;
 import static org.glassfish.mojarra.context.MojarraContextParam.SendPoweredByHeader;
 import static org.glassfish.mojarra.context.UrlBuilder.PROTOCOL_SEPARATOR;
 import static org.glassfish.mojarra.context.UrlBuilder.WEBSOCKET_PROTOCOL;
@@ -61,7 +61,6 @@
 import jakarta.servlet.http.HttpServletRequest;
 import jakarta.servlet.http.HttpServletResponse;
 import jakarta.servlet.http.HttpSession;
-import jakarta.servlet.http.PushBuilder;
 
 import org.glassfish.mojarra.RIConstants;
 import org.glassfish.mojarra.config.WebConfiguration;
@@ -574,7 +573,7 @@ public String encodeResourceURL(String url) {
         Util.notNull("url", url);
 
         String encodedURL = ((HttpServletResponse) response).encodeURL(url);
-        pushIfPossibleAndNecessary(encodedURL);
+        addEarlyHintIfPossibleAndNecessary(encodedURL);
 
         return encodedURL;
     }
@@ -1079,38 +1078,38 @@ public void release() {
     }
 
     @SuppressWarnings("unchecked")
-    private void pushIfPossibleAndNecessary(String encodedURL) {
+    private void addEarlyHintIfPossibleAndNecessary(String encodedURL) {
         FacesContext context = FacesContext.getCurrentInstance();
 
         if (!context.getApplication().getResourceHandler().isResourceURL(encodedURL)) {
             return;
         }
 
-        Set<String> resourceUrls = (Set<String>) context.getAttributes().computeIfAbsent(PUSH_RESOURCE_URLS_KEY_NAME, k -> new HashSet<>());
-
-        if (!resourceUrls.add(encodedURL)) {
+        // Skip when the client is revalidating, as it then most likely already has the resources cached.
+        if (!isEmpty(getRequestHeaderMap().get("If-Modified-Since"))) {
             return;
         }
 
-        PushBuilder pushBuilder = getPushBuilder(context);
+        if (response instanceof HttpServletResponse hres && !hres.isCommitted()) {
+            Set<String> resourceUrls = (Set<String>) context.getAttributes().computeIfAbsent(EARLY_HINTS_RESOURCE_URLS_KEY_NAME, k -> new HashSet<>());
 
-        if (pushBuilder != null) {
-            pushBuilder.path(encodedURL).push();
+            if (resourceUrls.add(encodedURL)) {
+                hres.addHeader("Link", "<" + encodedURL + ">;rel=preload");
+            }
         }
     }
 
-    private PushBuilder getPushBuilder(FacesContext context) {
-        ExternalContext extContext = context.getExternalContext();
-
-        if (extContext.getRequest() instanceof HttpServletRequest) {
-            HttpServletRequest hreq = (HttpServletRequest) extContext.getRequest();
+    /**
+     * Sends a single HTTP 103 (Early Hints) interim response with the {@code Link} preload headers collected so far,
+     * provided the response is not yet committed. Invoked once, right after the head resources have been rendered, so the
+     * client can start fetching the render-blocking resources while the body is still being rendered.
+     */
+    public static void sendEarlyHints(FacesContext context) {
+        Object resourceUrls = context.getAttributes().get(EARLY_HINTS_RESOURCE_URLS_KEY_NAME);
 
-            if (isEmpty(extContext.getRequestHeaderMap().get("If-Modified-Since"))) {
-                return hreq.newPushBuilder();
-            }
+        if (resourceUrls instanceof Set<?> set && !set.isEmpty() && context.getExternalContext().getResponse() instanceof HttpServletResponse hres && !hres.isCommitted()) {
+            hres.sendEarlyHints();
         }
-
-        return null;
     }
 
     private void doLastPhaseActions(FacesContext context, boolean outgoingResponseIsRedirect) {

impl/src/main/java/org/glassfish/mojarra/renderkit/html_basic/HeadRenderer.java

@@ -23,6 +23,7 @@
 import jakarta.faces.context.FacesContext;
 import jakarta.faces.context.ResponseWriter;
 
+import org.glassfish.mojarra.context.ExternalContextImpl;
 import org.glassfish.mojarra.renderkit.Attribute;
 import org.glassfish.mojarra.renderkit.AttributeManager;
 import org.glassfish.mojarra.renderkit.RenderKitUtils;
@@ -62,6 +63,7 @@ public void encodeChildren(FacesContext context, UIComponent component) throws I
     public void encodeEnd(FacesContext context, UIComponent component) throws IOException {
         ResponseWriter writer = context.getResponseWriter();
         encodeHeadResources(context);
+        ExternalContextImpl.sendEarlyHints(context);
         RenderKitUtils.flushPendingBehaviorEventListeners(context, component, null);
         writer.endElement("head");
     }

pom.xml

@@ -47,6 +47,7 @@
 
    <modules>
         <module>impl</module>
+        <module>test</module>
    </modules>
 
    <properties>

test/issue5746/pom.xml

@@ -0,0 +1,32 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+
+    Copyright (c) 2026 Contributors to Eclipse Foundation.
+
+    This program and the accompanying materials are made available under the
+    terms of the Eclipse Public License v. 2.0, which is available at
+    http://www.eclipse.org/legal/epl-2.0.
+
+    This Source Code may also be made available under the following Secondary
+    Licenses when the conditions for such availability set forth in the
+    Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
+    version 2 with the GNU Classpath Exception, which is available at
+    https://www.gnu.org/software/classpath/license.html.
+
+    SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
+
+-->
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <parent>
+        <groupId>org.glassfish.mojarra.test</groupId>
+        <artifactId>pom</artifactId>
+        <version>5.0.0-SNAPSHOT</version>
+    </parent>
+
+    <artifactId>issue5746</artifactId>
+    <packaging>war</packaging>
+
+    <name>Mojarra ${project.version} - IT - ${project.artifactId}</name>
+</project>

test/issue5746/src/main/webapp/WEB-INF/beans.xml

@@ -0,0 +1,24 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+
+    Copyright (c) 2026 Contributors to Eclipse Foundation.
+
+    This program and the accompanying materials are made available under the
+    terms of the Eclipse Public License v. 2.0, which is available at
+    http://www.eclipse.org/legal/epl-2.0.
+
+    This Source Code may also be made available under the following Secondary
+    Licenses when the conditions for such availability set forth in the
+    Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
+    version 2 with the GNU Classpath Exception, which is available at
+    https://www.gnu.org/software/classpath/license.html.
+
+    SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
+
+-->
+<beans
+    xmlns="https://jakarta.ee/xml/ns/jakartaee"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="https://jakarta.ee/xml/ns/jakartaee https://jakarta.ee/xml/ns/jakartaee/beans_4_1.xsd"
+    version="4.1">
+</beans>

test/issue5746/src/main/webapp/WEB-INF/faces-config.xml

@@ -0,0 +1,24 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+
+    Copyright (c) 2026 Contributors to Eclipse Foundation.
+
+    This program and the accompanying materials are made available under the
+    terms of the Eclipse Public License v. 2.0, which is available at
+    http://www.eclipse.org/legal/epl-2.0.
+
+    This Source Code may also be made available under the following Secondary
+    Licenses when the conditions for such availability set forth in the
+    Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
+    version 2 with the GNU Classpath Exception, which is available at
+    https://www.gnu.org/software/classpath/license.html.
+
+    SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
+
+-->
+<faces-config
+    xmlns="https://jakarta.ee/xml/ns/jakartaee"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="https://jakarta.ee/xml/ns/jakartaee https://jakarta.ee/xml/ns/jakartaee/web-facesconfig_4_1.xsd"
+    version="4.1">
+</faces-config>

test/issue5746/src/main/webapp/WEB-INF/web.xml

@@ -0,0 +1,45 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+
+    Copyright (c) 2026 Contributors to Eclipse Foundation.
+
+    This program and the accompanying materials are made available under the
+    terms of the Eclipse Public License v. 2.0, which is available at
+    http://www.eclipse.org/legal/epl-2.0.
+
+    This Source Code may also be made available under the following Secondary
+    Licenses when the conditions for such availability set forth in the
+    Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
+    version 2 with the GNU Classpath Exception, which is available at
+    https://www.gnu.org/software/classpath/license.html.
+
+    SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
+
+-->
+<web-app
+    xmlns="https://jakarta.ee/xml/ns/jakartaee"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="https://jakarta.ee/xml/ns/jakartaee https://jakarta.ee/xml/ns/jakartaee/web-app_6_1.xsd"
+    version="6.1">
+    <context-param>
+        <param-name>jakarta.faces.PROJECT_STAGE</param-name>
+        <param-value>${webapp.projectStage}</param-value>
+    </context-param>
+    <context-param>
+        <param-name>jakarta.faces.PARTIAL_STATE_SAVING</param-name>
+        <param-value>${webapp.partialStateSaving}</param-value>
+    </context-param>
+    <context-param>
+        <param-name>jakarta.faces.STATE_SAVING_METHOD</param-name>
+        <param-value>${webapp.stateSavingMethod}</param-value>
+    </context-param>    
+    <context-param>
+        <param-name>jakarta.faces.SERIALIZE_SERVER_STATE</param-name>
+        <param-value>${webapp.serializeServerState}</param-value>
+    </context-param>
+
+    <context-param>
+        <param-name>jakarta.faces.ENABLE_CSP_NONCE</param-name>
+        <param-value>true</param-value>
+    </context-param>
+</web-app>

test/issue5746/src/main/webapp/issue5746.xhtml

@@ -0,0 +1,33 @@
+<!DOCTYPE html>
+<!--
+
+    Copyright (c) 2026 Contributors to Eclipse Foundation.
+
+    This program and the accompanying materials are made available under the
+    terms of the Eclipse Public License v. 2.0, which is available at
+    http://www.eclipse.org/legal/epl-2.0.
+
+    This Source Code may also be made available under the following Secondary
+    Licenses when the conditions for such availability set forth in the
+    Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
+    version 2 with the GNU Classpath Exception, which is available at
+    https://www.gnu.org/software/classpath/license.html.
+
+    SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
+
+-->
+<html lang="en"
+    xmlns:h="jakarta.faces.html"
+>
+    <h:head>
+        <title>Early Hints 103</title>
+        <h:outputStylesheet library="css" name="style1.css" />
+        <h:outputStylesheet library="css" name="style2.css" />
+        <h:outputScript library="js" name="script1.js" />
+        <h:outputScript library="js" name="script2.js" />
+        <h:outputScript library="js" name="script3.js" />
+    </h:head>
+    <h:body>
+        <h1 id="content">Early Hints 103 test page</h1>
+    </h:body>
+</html>

test/issue5746/src/main/webapp/resources/css/style1.css

@@ -0,0 +1,4 @@
+/* Early Hints 103 test resource. */
+body {
+    font-family: sans-serif;
+}

test/issue5746/src/main/webapp/resources/css/style2.css

@@ -0,0 +1,4 @@
+/* Early Hints 103 test resource. */
+h1 {
+    color: #336699;
+}

test/issue5746/src/main/webapp/resources/js/script1.js

@@ -0,0 +1,2 @@
+// Early Hints 103 test resource.
+console.log("script1.js loaded");

test/issue5746/src/main/webapp/resources/js/script2.js

@@ -0,0 +1,2 @@
+// Early Hints 103 test resource.
+console.log("script2.js loaded");

test/issue5746/src/main/webapp/resources/js/script3.js

@@ -0,0 +1,2 @@
+// Early Hints 103 test resource.
+console.log("script3.js loaded");