Added MethodInvokingTransformer.

org.springframework.integration/src/main/java/org/springframework/integration/transformer/MethodInvokingTransformer.java

@@ -0,0 +1,73 @@
+/*
+ * Copyright 2002-2008 the original author or authors.
+ *
+ * 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 org.springframework.integration.transformer;
+
+import java.lang.reflect.Method;
+import java.util.Map;
+import java.util.Properties;
+
+import org.springframework.integration.message.Message;
+import org.springframework.integration.message.MessageBuilder;
+import org.springframework.integration.message.MessageHandlingException;
+import org.springframework.integration.message.MessageMappingMethodInvoker;
+
+/**
+ * @author Mark Fisher
+ */
+public class MethodInvokingTransformer implements Transformer {
+
+	private final MessageMappingMethodInvoker invoker;
+
+
+	public MethodInvokingTransformer(Object object, Method method) {
+		this.invoker = new MessageMappingMethodInvoker(object, method);
+	}
+
+	public MethodInvokingTransformer(Object object, String methodName) {
+		this.invoker = new MessageMappingMethodInvoker(object, methodName);
+	}
+
+
+	public Message<?> transform(Message<?> message) {
+		Object result = this.invoker.invokeMethod(message);
+		if (result instanceof Properties && !(message.getPayload() instanceof Properties)) {
+			Properties propertiesToSet = (Properties) result;
+			MessageBuilder<?> builder = MessageBuilder.fromMessage(message);
+			for (Object keyObject : propertiesToSet.keySet()) {
+				String key = (String) keyObject;
+				builder.setHeader(key, propertiesToSet.getProperty(key));
+			}
+			return builder.build();
+		}
+		else if (result instanceof Map && !(message.getPayload() instanceof Map)) {
+			Map<?, ?> attributesToSet = (Map <?, ?>) result;
+			MessageBuilder<?> builder = MessageBuilder.fromMessage(message);
+			for (Object key : attributesToSet.keySet()) {
+				if (!(key instanceof String)) {
+					throw new MessageHandlingException(message,
+							"Map returned from a Transformer method must have String-typed keys");
+				}
+				builder.setHeader((String) key, attributesToSet.get(key));
+			}
+			return builder.build();
+		}
+		else {
+			return MessageBuilder.fromPayload(result).copyHeaders(message.getHeaders()).build();
+		}
+	}
+
+}