CAMEL-22894: Extract direct and misc function factories from SimpleFunctionExpression

core/camel-core-languages/src/main/java/org/apache/camel/language/simple/SimpleFunctionDispatcher.java

@@ -27,6 +27,7 @@
 import org.apache.camel.language.simple.functions.HeaderFunctionFactory;
 import org.apache.camel.language.simple.functions.JoinFunctionFactory;
 import org.apache.camel.language.simple.functions.MathFunctionFactory;
+import org.apache.camel.language.simple.functions.MiscFunctionFactory;
 import org.apache.camel.language.simple.functions.RandomFunctionFactory;
 import org.apache.camel.language.simple.functions.SkipFunctionFactory;
 import org.apache.camel.language.simple.functions.StringFunctionFactory;
@@ -63,7 +64,8 @@ public final class SimpleFunctionDispatcher {
             new JoinFunctionFactory(),
             new MathFunctionFactory(),
             new StringFunctionFactory(),
-            new CollectionFunctionFactory());
+            new CollectionFunctionFactory(),
+            new MiscFunctionFactory());
 
     private static final List<Entry> EXPRESSION_ENTRIES = List.of(
             new Entry("camel-attachments", SimpleFunctionDispatcher::isAttachmentFunction),

core/camel-core-languages/src/main/java/org/apache/camel/language/simple/functions/DirectFunctionFactory.java

@@ -0,0 +1,119 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You 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 org.apache.camel.language.simple.functions;
+
+import org.apache.camel.CamelContext;
+import org.apache.camel.Expression;
+import org.apache.camel.language.simple.SimpleExpressionBuilder;
+import org.apache.camel.spi.SimpleLanguageFunctionFactory;
+import org.apache.camel.support.builder.ExpressionBuilder;
+import org.apache.camel.util.ObjectHelper;
+
+/**
+ * Built-in Simple keyword functions that are matched by exact name (no prefix): {@code ${id}},
+ * {@code ${messageTimestamp}}, {@code ${exchangeId}}, {@code ${exchange}}, {@code ${logExchange}},
+ * {@code ${exception}}, {@code ${exception.message}}, {@code ${exception.stacktrace}}, {@code ${threadId}},
+ * {@code ${threadName}}, {@code ${hostname}}, {@code ${camelId}}, {@code ${routeId}}, {@code ${fromRouteId}},
+ * {@code ${routeGroup}}, {@code ${stepId}}, {@code ${null}}.
+ *
+ * <p>
+ * These functions must be dispatched <em>before</em> the inline prefix checks in {@code SimpleFunctionExpression}
+ * (e.g., the {@code exception} OGNL check and the {@code exchange} OGNL check), because names like {@code exchangeId}
+ * and {@code exception.message} share a prefix with those checks.
+ */
+public final class DirectFunctionFactory implements SimpleLanguageFunctionFactory {
+
+    @Override
+    public Expression createFunction(CamelContext camelContext, String function, int index) {
+        if (ObjectHelper.equal(function, "id")) {
+            return ExpressionBuilder.messageIdExpression();
+        } else if (ObjectHelper.equal(function, "messageTimestamp")) {
+            return ExpressionBuilder.messageTimestampExpression();
+        } else if (ObjectHelper.equal(function, "exchangeId")) {
+            return ExpressionBuilder.exchangeIdExpression();
+        } else if (ObjectHelper.equal(function, "exchange")) {
+            return ExpressionBuilder.exchangeExpression();
+        } else if (ObjectHelper.equal(function, "logExchange")) {
+            return ExpressionBuilder.logExchange();
+        } else if (ObjectHelper.equal(function, "exception")) {
+            return ExpressionBuilder.exchangeExceptionExpression();
+        } else if (ObjectHelper.equal(function, "exception.message")) {
+            return ExpressionBuilder.exchangeExceptionMessageExpression();
+        } else if (ObjectHelper.equal(function, "exception.stacktrace")) {
+            return ExpressionBuilder.exchangeExceptionStackTraceExpression();
+        } else if (ObjectHelper.equal(function, "threadId")) {
+            return ExpressionBuilder.threadIdExpression();
+        } else if (ObjectHelper.equal(function, "threadName")) {
+            return ExpressionBuilder.threadNameExpression();
+        } else if (ObjectHelper.equal(function, "hostname")) {
+            return ExpressionBuilder.hostnameExpression();
+        } else if (ObjectHelper.equal(function, "camelId")) {
+            return ExpressionBuilder.camelContextNameExpression();
+        } else if (ObjectHelper.equal(function, "routeId")) {
+            return ExpressionBuilder.routeIdExpression();
+        } else if (ObjectHelper.equal(function, "fromRouteId")) {
+            return ExpressionBuilder.fromRouteIdExpression();
+        } else if (ObjectHelper.equal(function, "routeGroup")) {
+            return ExpressionBuilder.routeGroupExpression();
+        } else if (ObjectHelper.equal(function, "stepId")) {
+            return ExpressionBuilder.stepIdExpression();
+        } else if (ObjectHelper.equal(function, "null")) {
+            return SimpleExpressionBuilder.nullExpression();
+        }
+
+        return null;
+    }
+
+    @Override
+    public String createCode(CamelContext camelContext, String function, int index) {
+        if (ObjectHelper.equal(function, "id")) {
+            return "message.getMessageId()";
+        } else if (ObjectHelper.equal(function, "messageTimestamp")) {
+            return "message.getMessageTimestamp()";
+        } else if (ObjectHelper.equal(function, "exchangeId")) {
+            return "exchange.getExchangeId()";
+        } else if (ObjectHelper.equal(function, "exchange")) {
+            return "exchange";
+        } else if (ObjectHelper.equal(function, "logExchange")) {
+            return "logExchange(exchange)";
+        } else if (ObjectHelper.equal(function, "exception")) {
+            return "exception(exchange)";
+        } else if (ObjectHelper.equal(function, "exception.message")) {
+            return "exceptionMessage(exchange)";
+        } else if (ObjectHelper.equal(function, "exception.stacktrace")) {
+            return "exceptionStacktrace(exchange)";
+        } else if (ObjectHelper.equal(function, "threadId")) {
+            return "threadId()";
+        } else if (ObjectHelper.equal(function, "threadName")) {
+            return "threadName()";
+        } else if (ObjectHelper.equal(function, "hostname")) {
+            return "hostName()";
+        } else if (ObjectHelper.equal(function, "camelId")) {
+            return "context.getName()";
+        } else if (ObjectHelper.equal(function, "fromRouteId")) {
+            return "fromRouteId(exchange)";
+        } else if (ObjectHelper.equal(function, "routeId")) {
+            return "routeId(exchange)";
+        } else if (ObjectHelper.equal(function, "stepId")) {
+            return "stepId(exchange)";
+        } else if (ObjectHelper.equal(function, "null")) {
+            return "null";
+        }
+
+        return null;
+    }
+}