Implemented servlet 6.1 redirect with content

jetty-core/jetty-http/src/main/java/org/eclipse/jetty/http/HttpStatus.java

@@ -383,7 +383,7 @@ public static boolean isSuccess(int code)
      */
     public static boolean isRedirection(int code)
     {
-        return ((300 <= code) && (code <= 399));
+        return ((300 <= code) && (code <= 399) && code != 304);
     }
 
     /**

jetty-core/jetty-server/src/main/config/etc/jetty.xml

@@ -67,6 +67,7 @@
       <Set name="requestCookieCompliance"><Call class="org.eclipse.jetty.http.CookieCompliance" name="from"><Arg><Property name="jetty.httpConfig.requestCookieCompliance" default="RFC6265"/></Arg></Call></Set>
       <Set name="responseCookieCompliance"><Call class="org.eclipse.jetty.http.CookieCompliance" name="from"><Arg><Property name="jetty.httpConfig.responseCookieCompliance" default="RFC6265"/></Arg></Call></Set>
       <Set name="relativeRedirectAllowed"><Property name="jetty.httpConfig.relativeRedirectAllowed" default="false"/></Set>
+      <Set name="generateRedirectBody" property="jetty.httpConfig.generateRedirectBody"/>
       <Set name="useInputDirectByteBuffers" property="jetty.httpConfig.useInputDirectByteBuffers"/>
       <Set name="useOutputDirectByteBuffers" property="jetty.httpConfig.useOutputDirectByteBuffers"/>
     </New>

jetty-core/jetty-server/src/main/config/modules/server.mod

@@ -65,6 +65,9 @@ etc/jetty.xml
 ## Relative Redirect Locations allowed
 # jetty.httpConfig.relativeRedirectAllowed=true
 
+## Redirect body generated
+# jetty.httpConfig.generateRedirectBody=false
+
 ## Whether to use direct ByteBuffers for reading or writing
 # jetty.httpConfig.useInputDirectByteBuffers=true
 # jetty.httpConfig.useOutputDirectByteBuffers=true

jetty-core/jetty-server/src/main/java/org/eclipse/jetty/server/ConnectionMetaData.java

@@ -52,7 +52,9 @@ default boolean isSecure()
 
     /**
      * @return whether the functionality of pushing resources is supported
+     * @deprecated in favour of 103 Early Hints
      */
+    @Deprecated
     default boolean isPushSupported()
     {
         return false;

jetty-core/jetty-server/src/main/java/org/eclipse/jetty/server/HttpConfiguration.java

@@ -84,6 +84,7 @@ public class HttpConfiguration implements Dumpable
     private MultiPartCompliance _multiPartCompliance = MultiPartCompliance.RFC7578;
     private boolean _notifyRemoteAsyncErrors = true;
     private boolean _relativeRedirectAllowed = true;
+    private boolean _generateRedirectBody = false;
     private HostPort _serverAuthority;
     private SocketAddress _localAddress;
     private int _maxUnconsumedRequestContentReads = 16;
@@ -158,6 +159,7 @@ public HttpConfiguration(HttpConfiguration config)
         _complianceViolationListeners.addAll(config._complianceViolationListeners);
         _notifyRemoteAsyncErrors = config._notifyRemoteAsyncErrors;
         _relativeRedirectAllowed = config._relativeRedirectAllowed;
+        _generateRedirectBody = config._generateRedirectBody;
         _uriCompliance = config._uriCompliance;
         _serverAuthority = config._serverAuthority;
         _localAddress = config._localAddress;
@@ -716,6 +718,23 @@ public boolean isRelativeRedirectAllowed()
         return _relativeRedirectAllowed;
     }
 
+    /**
+     * @param generate True if a redirection body will be generated if no response body is supplied.
+     */
+    public void setGenerateRedirectBody(boolean generate)
+    {
+        _generateRedirectBody = generate;
+    }
+
+    /**
+     * @return True if a redirection body will be generated if no response body is supplied.
+     */
+    @ManagedAttribute("Whether a redirection response body will be generated")
+    public boolean isGenerateRedirectBody()
+    {
+        return _generateRedirectBody;
+    }
+
     /**
      * Get the SocketAddress override to be reported as the local address of all connections
      *

jetty-core/jetty-server/src/main/java/org/eclipse/jetty/server/Response.java

@@ -15,6 +15,7 @@
 
 import java.io.OutputStream;
 import java.nio.ByteBuffer;
+import java.nio.charset.StandardCharsets;
 import java.util.ListIterator;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.TimeoutException;
@@ -32,12 +33,14 @@
 import org.eclipse.jetty.http.HttpStatus;
 import org.eclipse.jetty.http.HttpURI;
 import org.eclipse.jetty.http.HttpVersion;
+import org.eclipse.jetty.http.MimeTypes;
 import org.eclipse.jetty.http.Trailers;
 import org.eclipse.jetty.io.ByteBufferPool;
 import org.eclipse.jetty.io.Content;
 import org.eclipse.jetty.io.QuietException;
 import org.eclipse.jetty.server.handler.ErrorHandler;
 import org.eclipse.jetty.server.internal.HttpChannelState;
+import org.eclipse.jetty.util.BufferUtil;
 import org.eclipse.jetty.util.Callback;
 import org.eclipse.jetty.util.StringUtil;
 import org.eclipse.jetty.util.URIUtil;
@@ -262,10 +265,7 @@ static void sendRedirect(Request request, Response response, Callback callback,
      */
     static void sendRedirect(Request request, Response response, Callback callback, String location, boolean consumeAvailable)
     {
-        int code = HttpMethod.GET.is(request.getMethod()) || request.getConnectionMetaData().getHttpVersion().getVersion() < HttpVersion.HTTP_1_1.getVersion()
-            ? HttpStatus.MOVED_TEMPORARILY_302
-            : HttpStatus.SEE_OTHER_303;
-        sendRedirect(request, response, callback, code, location, consumeAvailable);
+        sendRedirect(request, response, callback, 0, location, consumeAvailable);
     }
 
     /**
@@ -283,23 +283,47 @@ static void sendRedirect(Request request, Response response, Callback callback,
      */
     static void sendRedirect(Request request, Response response, Callback callback, int code, String location, boolean consumeAvailable)
     {
-        if (!HttpStatus.isRedirection(code))
+        sendRedirect(request, response, callback, code, location, consumeAvailable, null);
+    }
+
+    /**
+     * <p>Sends a {@code 302} HTTP redirect status code to the given location.</p>
+     *
+     * @param request the HTTP request
+     * @param response the HTTP response
+     * @param callback the callback to complete
+     * @param code the redirect HTTP status code, or 0 for a default
+     * @param location the redirect location as an absolute URI or encoded relative URI path.
+     * @param consumeAvailable whether to consumer the available request content
+     * @param content the content of the response, or null for a generated HTML message if {@link HttpConfiguration#isGenerateRedirectBody()} is {@code true}.
+     * @see #toRedirectURI(Request, String)
+     * @throws IllegalArgumentException if the status code is not a redirect, or the location is {@code null}
+     * @throws IllegalStateException if the response is already {@link #isCommitted() committed}
+     */
+    static void sendRedirect(Request request, Response response, Callback callback, int code, String location, boolean consumeAvailable, ByteBuffer content)
+    {
+        if (response.isCommitted())
         {
-            callback.failed(new IllegalArgumentException("Not a 3xx redirect code"));
+            callback.failed(new IllegalStateException("Committed"));
             return;
         }
 
-        if (location == null)
+        if (code <= 0)
+            code = HttpMethod.GET.is(request.getMethod()) || request.getConnectionMetaData().getHttpVersion().getVersion() < HttpVersion.HTTP_1_1.getVersion()
+            ? HttpStatus.MOVED_TEMPORARILY_302
+            : HttpStatus.SEE_OTHER_303;
+        if (!HttpStatus.isRedirection(code))
         {
-            callback.failed(new IllegalArgumentException("No location"));
+            callback.failed(new IllegalArgumentException("Not a 3xx redirect code"));
             return;
         }
 
-        if (response.isCommitted())
+        if (location == null)
         {
-            callback.failed(new IllegalStateException("Committed"));
+            callback.failed(new IllegalArgumentException("No location"));
             return;
         }
+        location = toRedirectURI(request, location);
 
         if (consumeAvailable)
         {
@@ -317,9 +341,22 @@ static void sendRedirect(Request request, Response response, Callback callback,
             }
         }
 
-        response.getHeaders().put(HttpHeader.LOCATION, toRedirectURI(request, location));
+        if (content == null && request.getConnectionMetaData().getHttpConfiguration().isGenerateRedirectBody())
+        {
+            response.getHeaders().put(MimeTypes.Type.TEXT_HTML_8859_1.getContentTypeField());
+            String body = """
+            <!DOCTYPE html>
+            <html lang="en">
+            <head><meta charset="ISO-8859-1"/><meta http-equiv="refresh" content="0; URL=%s/"/><title>Redirecting...</title></head>
+            <body><p>If you are not redirected, <a href="%s">click here</a>.</p></body>
+            </html>
+            """.formatted(location, location);
+            content = BufferUtil.toBuffer(body, StandardCharsets.ISO_8859_1);
+        }
+
+        response.getHeaders().put(HttpHeader.LOCATION, location);
         response.setStatus(code);
-        response.write(true, null, callback);
+        response.write(true, content, callback);
     }
 
     /**