1 files changed, 69 insertions, 0 deletions
diff --git a/common/src/main/java/org/onap/so/client/dmaap/DmaapPropertiesLoader.java b/common/src/main/java/org/onap/so/client/dmaap/DmaapPropertiesLoader.java
new file mode 100644
index 0000000000..3064f6142f
--- /dev/null
+++ b/common/src/main/java/org/onap/so/client/dmaap/DmaapPropertiesLoader.java
@@ -0,0 +1,69 @@
+/*-
+ * ============LICENSE_START=======================================================
+ * ONAP - SO
+ * ================================================================================
+ * Copyright (C) 2017 AT&T Intellectual Property. All rights reserved.
+ * ================================================================================
+ * 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.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.so.client.dmaap;
+
+import java.util.ServiceLoader;
+
+public class DmaapPropertiesLoader {
+	/* required to make ServiceLoader thread safe */
+	private static final ThreadLocal<ServiceLoader<DmaapProperties>> services = new ThreadLocal<ServiceLoader<DmaapProperties>>() {
+		@Override
+		protected ServiceLoader<DmaapProperties> initialValue() {
+			return ServiceLoader.load(DmaapProperties.class);
+		}
+	};
+
+	private DmaapPropertiesLoader() {
+	}
+	
+	private static class Helper {
+		private static final DmaapPropertiesLoader INSTANCE = new DmaapPropertiesLoader();
+	}
+	
+	public static DmaapPropertiesLoader getInstance() {
+		return Helper.INSTANCE;
+	}
+	public DmaapProperties getImpl() {
+		return this.getImpl(false);
+	}
+	public DmaapProperties getNewImpl() {
+		return this.getImpl(true);
+	}
+	private DmaapProperties getImpl(boolean forceNewInstance) {
+		
+		ServiceLoader<DmaapProperties> loader = this.services.get();
+		for (DmaapProperties service : loader) {
+			if (forceNewInstance) {
+				try {
+					return service.getClass().newInstance();
+				} catch (InstantiationException | IllegalAccessException e) {
+					/* all spi implementations must provide a public
+					 * no argument constructor
+					 */
+				}
+			} else {
+				return service;
+			}
+		}
+		
+		return null;
+	}
+}