[UNDERTOW-1735] add reason-phrase handler and make response-code obey…

… doc contract of one-by-one execution

core/src/main/java/io/undertow/UndertowMessages.java

@@ -26,6 +26,7 @@
 import javax.net.ssl.SSLHandshakeException;
 import javax.net.ssl.SSLPeerUnverifiedException;
 
+import io.undertow.server.HttpServerExchange;
 import io.undertow.server.RequestTooBigException;
 import io.undertow.server.handlers.form.MultiPartParserDefinition;
 import io.undertow.util.UrlDecodeException;
@@ -647,4 +648,6 @@ public interface UndertowMessages {
     @Message(id = 208, value = "Failed to allocate resource")
     IOException failedToAllocateResource();
 
+    @Message(id = 209, value = "Exchange '%s' already has body or is blocking.")
+    IOException exhangeBlockingOrBlocking(final HttpServerExchange e);
 }

core/src/main/java/io/undertow/server/handlers/ReasonPhraseHandler.java

@@ -0,0 +1,66 @@
+/*
+ * JBoss, Home of Professional Open Source.
+ * Copyright 2023 Red Hat, Inc., and individual contributors
+ * as indicated by the @author tags.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+
+package io.undertow.server.handlers;
+
+import io.undertow.UndertowLogger;
+import io.undertow.server.HttpHandler;
+import io.undertow.server.HttpServerExchange;
+
+/**
+ * A handler which simply sets a response code.
+ *
+ * @author <a href="mailto:[email protected]">Bartosz Baranowski</a>
+ */
+public final class ReasonPhraseHandler implements HttpHandler {
+
+    private static final boolean debugEnabled;
+
+    static {
+        debugEnabled = UndertowLogger.PREDICATE_LOGGER.isDebugEnabled();
+    }
+
+    private final String reasonPhrase;
+
+    private final HttpHandler next;
+    /**
+     * Construct a new instance.
+     *
+     * @param reasonPhrase the reason phrase to be set in status line
+     */
+    public ReasonPhraseHandler(final HttpHandler next, final String reasonPhrase) {
+        this.next = next;
+        this.reasonPhrase = reasonPhrase;
+    }
+
+    @Override
+    public void handleRequest(final HttpServerExchange exchange) throws Exception {
+        exchange.setReasonPhrase(reasonPhrase);
+        if(debugEnabled) {
+            UndertowLogger.PREDICATE_LOGGER.debugf("Reason phrase set to [%s] for %s.", this.reasonPhrase, exchange);
+        }
+        if(next != null) {
+            next.handleRequest(exchange);
+        }
+    }
+
+    @Override
+    public String toString() {
+        return "reason-phrase( " + this.reasonPhrase + " )";
+    }
+}

core/src/main/java/io/undertow/server/handlers/ResponseCodeHandler.java

@@ -64,13 +64,36 @@ public final class ResponseCodeHandler implements HttpHandler {
 
     private final int responseCode;
 
+    private HttpHandler next;
     /**
      * Construct a new instance.
      *
      * @param responseCode the response code to set
+     * @param next next handler
      */
-    public ResponseCodeHandler(final int responseCode) {
+    public ResponseCodeHandler(final HttpHandler next, final int responseCode) {
+        assert responseCode > 99;
+        assert responseCode < 600;
         this.responseCode = responseCode;
+        this.next = next;
+    }
+
+    /**
+     * Construct a new instance.
+     *
+     * @param responseCode the response code to set
+     * @param next next handler
+     */
+    public ResponseCodeHandler(final int responseCode) {
+        this(null,responseCode);
+    }
+
+    public HttpHandler getNext() {
+        return next;
+    }
+
+    public void setNext(HttpHandler next) {
+        this.next = next;
     }
 
     @Override
@@ -79,6 +102,9 @@ public void handleRequest(final HttpServerExchange exchange) throws Exception {
         if(debugEnabled) {
             UndertowLogger.PREDICATE_LOGGER.debugf("Response code set to [%s] for %s.", responseCode, exchange);
         }
+        if(next != null) {
+            next.handleRequest(exchange);
+        }
     }
 
     @Override

core/src/main/java/io/undertow/server/handlers/ResponseHandler.java

@@ -0,0 +1,109 @@
+/*
+ * JBoss, Home of Professional Open Source.
+ * Copyright 2023 Red Hat, Inc., and individual contributors
+ * as indicated by the @author tags.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package io.undertow.server.handlers;
+
+import io.undertow.UndertowLogger;
+import io.undertow.UndertowMessages;
+import io.undertow.server.HttpHandler;
+import io.undertow.server.HttpServerExchange;
+import io.undertow.util.HeaderMap;
+import io.undertow.util.Headers;
+
+/**
+ * Class which handles set operations for response: code, reason phrase and potentially body and type. Status code is required
+ * parameter.<br>
+ * The response handler allows to set response body as well. <br>
+ * response(code=404, reason='dont like it') is roughly equivalent to reason-phrase('dont like it');response-code(404)"<br>
+ *
+ * @author <a href="mailto:[email protected]">Bartosz Baranowski</a>
+ */
+public class ResponseHandler implements HttpHandler {
+
+    private static final String DEFAULT_BODY_TYPE = "text/html";
+    private static final boolean debugEnabled;
+
+    static {
+        debugEnabled = UndertowLogger.PREDICATE_LOGGER.isDebugEnabled();
+    }
+
+    private final String body;
+    private final String type;
+    private final int code;
+    private final String reason;
+    private HttpHandler chained;
+
+    // TODO: review parsing/execution rules. For some reason without next, this particular handler does not ignore
+    // trailing handlers.
+    public ResponseHandler(final int code, final String reason) {
+        this(code, reason, null, null);
+    }
+
+    public ResponseHandler(final int code, final String reason, final String body) {
+        this(code, reason, body, DEFAULT_BODY_TYPE);
+    }
+
+    public ResponseHandler(final int code, final String reason, final String body, final String type) {
+        this.body = body;
+        this.type = type;
+        // toString only
+        this.code = code;
+        this.reason = reason;
+        if (reason != null) {
+            this.chained = new ReasonPhraseHandler(null, reason);
+        }
+        this.chained = new ResponseCodeHandler(this.chained, code);
+    }
+
+    @Override
+    public void handleRequest(HttpServerExchange exchange) throws Exception {
+        this.chained.handleRequest(exchange);
+        if (this.body != null) {
+            final byte[] bodyBytes = this.body.getBytes("UTF-8");
+            final HeaderMap responseHeaders = exchange.getResponseHeaders();
+            if (responseHeaders.contains(Headers.CONTENT_LENGTH) || responseHeaders.contains(Headers.CONTENT_TYPE) || exchange.isBlocking()) {
+                //TODO: need user feedback
+                throw UndertowMessages.MESSAGES.exhangeBlockingOrBlocking(exchange);
+            }
+            responseHeaders.add(Headers.CONTENT_TYPE, this.type);
+            responseHeaders.add(Headers.CONTENT_LENGTH, bodyBytes.length);
+            exchange.startBlocking();
+            if (exchange.isInIoThread()) {
+                exchange.dispatch(new HttpHandler() {
+
+                    @Override
+                    public void handleRequest(HttpServerExchange exchange) throws Exception {
+                        exchange.getOutputStream().write(bodyBytes);
+                    }
+                });
+            } else {
+                exchange.getOutputStream().write(bodyBytes);
+            }
+
+            if (debugEnabled) {
+                UndertowLogger.PREDICATE_LOGGER.debugf("Respons body set to \n[%s]\nfor %s.", this.body, exchange);
+            }
+        }
+    }
+
+    @Override
+    public String toString() {
+        return "response( code='" + code + "'" + ((this.reason != null) ? ", reason='" + this.reason + "'" : "") + ""
+                + ((this.body != null) ? ", type='" + this.type + "', body='" + this.body + "'" : "") + " )";
+    }
+
+}

core/src/main/java/io/undertow/server/handlers/builder/ReasonPhraseHandlerBuilder.java

@@ -0,0 +1,68 @@
+/*
+ * JBoss, Home of Professional Open Source.
+ * Copyright 2023 Red Hat, Inc., and individual contributors
+ * as indicated by the @author tags.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+
+package io.undertow.server.handlers.builder;
+
+import io.undertow.server.HandlerWrapper;
+import io.undertow.server.HttpHandler;
+import io.undertow.server.handlers.ReasonPhraseHandler;
+
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+
+/**
+ * @author <a href="mailto:[email protected]">Bartosz Baranowski</a>
+ */
+public class ReasonPhraseHandlerBuilder implements HandlerBuilder {
+    @Override
+    public String name() {
+        return "reason-phrase";
+    }
+
+    @Override
+    public Map<String, Class<?>> parameters() {
+        Map<String, Class<?>> parameters = new HashMap<>();
+        parameters.put("value", String.class);
+        return parameters;
+    }
+
+    @Override
+    public Set<String> requiredParameters() {
+        final Set<String> req = new HashSet<>();
+        req.add("value");
+        return req;
+    }
+
+    @Override
+    public String defaultParameter() {
+        return "value";
+    }
+
+    @Override
+    public HandlerWrapper build(final Map<String, Object> config) {
+        final String value = (String) config.get("value");
+        return new HandlerWrapper() {
+            @Override
+            public HttpHandler wrap(HttpHandler handler) {
+                return new ReasonPhraseHandler(handler, value);
+            }
+        };
+    }
+}

core/src/main/java/io/undertow/server/handlers/builder/ResponseCodeHandlerBuilder.java

@@ -61,7 +61,7 @@ public HandlerWrapper build(final Map<String, Object> config) {
         return new HandlerWrapper() {
             @Override
             public HttpHandler wrap(HttpHandler handler) {
-                return new ResponseCodeHandler(value);
+                return new ResponseCodeHandler(handler, value);
             }
         };
     }