INT-1188, TimeBasedUUIDGenerator

spring-integration-core/src/main/java/org/springframework/integration/core/MessageHeaders.java

@@ -31,7 +31,6 @@ import java.util.UUID;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
-
 import org.springframework.integration.history.MessageHistory;
 
 /**
@@ -78,7 +77,7 @@ public final class MessageHeaders implements Map<String, Object>, Serializable {
 
 	public MessageHeaders(Map<String, Object> headers) {
 		this.headers = (headers != null) ? new HashMap<String, Object>(headers) : new HashMap<String, Object>();
-		this.headers.put(ID, UUID.randomUUID());
+		this.headers.put(ID, TimeBasedUUIDGenerator.generateId());
 		this.headers.put(TIMESTAMP, new Long(System.currentTimeMillis()));
 		if (this.headers.get(HISTORY) == null) {
 			this.headers.put(HISTORY, new MessageHistory());

spring-integration-core/src/main/java/org/springframework/integration/core/TimeBasedUUIDGenerator.java

@@ -0,0 +1,69 @@
+/*
+ * Copyright 2002-2010 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.core;
+
+import java.util.UUID;
+
+/**
+ * Will generate time-based UUID (version 1 UUID).
+ * This will allow Message ID to be unique but also contain an 
+ * embedded timestamp which could be retrieved via UUID.timestamp()
+ * 
+ * @author Oleg Zhurakousky
+ * @since 2.0
+ */
+class TimeBasedUUIDGenerator {
+	public static final Object lock = new Object();
+	private static long lastTime;
+
+	/**
+	 * Will generate unique time based UUID where the next UUID is 
+	 * always greater then the previous.
+	 * 
+	 * @return
+	 */
+	public final static UUID generateId() {
+		return generateIdFromTimestamp(System.currentTimeMillis());
+	}
+	/**
+	 * 
+	 * @param currentTimeMillis
+	 * @return
+	 */
+	public final static UUID generateIdFromTimestamp(long currentTimeMillis){
+		long time;
+		synchronized (lock) {
+			if (currentTimeMillis > lastTime) {
+				lastTime = currentTimeMillis;
+			} else  {
+				currentTimeMillis = ++lastTime;
+			}
+		}
+		
+		time = currentTimeMillis;
+		
+		// low Time
+		time = currentTimeMillis << 32;
+		
+		// mid Time
+		time |= (currentTimeMillis & 0xFFFF00000000L) >> 16;
+
+		// hi Time
+		time |= 0x1000 | ((currentTimeMillis >> 48) & 0x0FFF); // version 1
+
+		return new UUID(time, System.nanoTime());
+	}
+}