1 files changed, 85 insertions, 0 deletions
diff --git a/eelf-logger/eelf-logger-api/src/main/java/org/onap/dcae/utils/eelf/logger/api/log/EELFLogFactory.java b/eelf-logger/eelf-logger-api/src/main/java/org/onap/dcae/utils/eelf/logger/api/log/EELFLogFactory.java
new file mode 100644
index 0000000..2cfb2ec
--- /dev/null
+++ b/eelf-logger/eelf-logger-api/src/main/java/org/onap/dcae/utils/eelf/logger/api/log/EELFLogFactory.java
@@ -0,0 +1,85 @@
+/*
+ * ================================================================================
+ * Copyright (c) 2018 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.dcae.utils.eelf.logger.api.log;
+
+
+import org.onap.dcae.utils.eelf.logger.api.noop.NoOpEELFLogger;
+
+import java.lang.reflect.InvocationTargetException;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Map;
+import java.util.ServiceLoader;
+import java.util.WeakHashMap;
+
+/**
+ * EELF Log Factory uses {@link ServiceLoader} to load implementations of {@link EELFLogger} in application
+ * classpath. If no EELF Logging implementations are found - eelf logging is disabled and {@link NoOpEELFLogger}
+ * is used.
+ *
+ * @author Rajiv Singla
+ */
+public class EELFLogFactory {
+
+    private static final ServiceLoader<EELFLogger> SERVICE_LOADER = ServiceLoader.load(EELFLogger.class);
+    private static final Map<Class<?>, EELFLogger> LOGGER_CACHE = new WeakHashMap<>(64);
+
+    private static List<EELFLogger> loggerImplementations = new LinkedList<>();
+
+    static {
+
+        for (EELFLogger loggerImplementation : SERVICE_LOADER) {
+            loggerImplementations.add(loggerImplementation);
+        }
+
+        if (loggerImplementations.isEmpty()) {
+            System.err.println(
+                    "EELF LOGGING ERROR: Unable to find any EELF Logger Implementations in the classpath.");
+            System.err.println("=============EELF LOGGING IS DISABLED================");
+            loggerImplementations.add(NoOpEELFLogger.getInstance());
+        }
+
+    }
+
+    private EELFLogFactory() {
+        // private constructor
+    }
+
+    public static <T> EELFLogger getLogger(Class<T> clazz) {
+
+        if (LOGGER_CACHE.get(clazz) != null) {
+            return LOGGER_CACHE.get(clazz);
+        }
+
+        EELFLogger EELFLogger = null;
+        try {
+            EELFLogger = loggerImplementations.get(0).getClass().getConstructor(Class.class)
+                    .newInstance(clazz);
+            return EELFLogger;
+
+        } catch (
+                InstantiationException | IllegalAccessException | InvocationTargetException | NoSuchMethodException e) {
+            throw new IllegalStateException("Error while Creating EELF Logger", e);
+        }
+
+    }
+
+
+}