1 files changed, 150 insertions, 0 deletions
diff --git a/openecomp-be/lib/openecomp-core-lib/openecomp-facade-lib/openecomp-facade-api/src/main/java/org/openecomp/core/factory/impl/FactoryManager.java b/openecomp-be/lib/openecomp-core-lib/openecomp-facade-lib/openecomp-facade-api/src/main/java/org/openecomp/core/factory/impl/FactoryManager.java
new file mode 100644
index 0000000000..ec2d93f35b
--- /dev/null
+++ b/openecomp-be/lib/openecomp-core-lib/openecomp-facade-lib/openecomp-facade-api/src/main/java/org/openecomp/core/factory/impl/FactoryManager.java
@@ -0,0 +1,150 @@
+/*
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2019 Nordix Foundation
+ *  ================================================================================
+ *  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.
+ *
+ *  SPDX-License-Identifier: Apache-2.0
+ *  ============LICENSE_END=========================================================
+ */
+
+package org.openecomp.core.factory.impl;
+
+import com.amdocs.zusammen.utils.facade.impl.FactoryConfig;
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+import org.apache.commons.lang3.StringUtils;
+import org.openecomp.core.utilities.CommonMethods;
+import org.openecomp.sdc.common.errors.CoreException;
+import org.openecomp.sdc.common.errors.ErrorCategory;
+import org.openecomp.sdc.common.errors.ErrorCode;
+
+public class FactoryManager {
+
+    private static final FactoryManager instance = new FactoryManager();
+    private static final String ERROR_CODE_E0001 = "E0001";
+    /**
+     * Temporary registry of default implementations. The map keeps class names rather then class
+     * types to allow unloading of those classes from memory by garbage collector if factory is not
+     * actually used.
+     */
+    private final Map<String, String> factoryRegistry = new ConcurrentHashMap<>();
+    /**
+     * Cached factory instances.
+     */
+    private final Map<String, AbstractFactoryBase> factoryInstanceMap = new ConcurrentHashMap<>();
+
+
+    private FactoryManager() {
+        initializeFactoryRegistry();
+    }
+
+    public static synchronized FactoryManager getInstance() {
+        return instance;
+    }
+
+    private void initializeFactoryRegistry() {
+        final Map<String, String> factoryMap = FactoryConfig.getFactoriesMap();
+
+        for (final Map.Entry<String, String> entry : factoryMap.entrySet()) {
+            final String abstractClassName = entry.getKey();
+            final String concreteTypeName = entry.getValue();
+
+            if (StringUtils.isEmpty(concreteTypeName)) {
+                throw new CoreException(
+                    new ErrorCode.ErrorCodeBuilder().withId("E0003")
+                        .withMessage("Missing configuration value:" + concreteTypeName + ".")
+                        .withCategory(ErrorCategory.SYSTEM).build());
+
+            }
+            registerFactory(abstractClassName, concreteTypeName);
+        }
+    }
+
+    /**
+     * Instantiates the configured implementation of an abstract factory.
+     *
+     * @param <F>         Type specific abstract factory for concrete Java interface
+     * @param factoryType Java class of type specific abstract factory
+     * @return Instance of implementation class
+     */
+    @SuppressWarnings("unchecked")
+    public <F extends AbstractFactoryBase> F getFactoryInstance(Class<F> factoryType) {
+        if (factoryType == null) {
+            throw new CoreException(
+                new ErrorCode.ErrorCodeBuilder().withId(ERROR_CODE_E0001)
+                    .withMessage("Mandatory input factory type.").withCategory(ErrorCategory.SYSTEM)
+                    .build());
+
+        }
+        final String factoryTypeName = factoryType.getName();
+        // Check if the factory is already cached
+        if (factoryInstanceMap.get(factoryTypeName) == null) {
+            //if not, create a new one and cache it
+            // Get the implementation class name
+            final String implName = factoryRegistry.get(factoryTypeName);
+
+            if (StringUtils.isEmpty(implName)) {
+                throw new CoreException(
+                    new ErrorCode.ErrorCodeBuilder().withId(ERROR_CODE_E0001)
+                        .withMessage("Mandatory input factory implementation.")
+                        .withCategory(ErrorCategory.SYSTEM).build());
+            }
+
+            F factory = CommonMethods.newInstance(implName, factoryType);
+            factory.init();
+            // Cache the instantiated singleton
+            factoryInstanceMap.putIfAbsent(factoryTypeName, factory);
+        }
+
+        return (F) factoryInstanceMap.get(factoryTypeName);
+    }
+
+    public void registerFactory(final String factoryName, final String implName) {
+        factoryRegistry.put(factoryName, implName);
+    }
+
+    /**
+     * Unregister factory and removes the cached instance if any.
+     * @param factoryName the factory name to unregister
+     */
+    public void unregisterFactory(final String factoryName) {
+        final String factoryClass = factoryRegistry.get(factoryName);
+        if (StringUtils.isNotEmpty(factoryClass)) {
+            factoryInstanceMap.remove(factoryClass);
+            factoryRegistry.remove(factoryName);
+        }
+    }
+
+    /**
+     * Removes the cached factory instance if any.
+     *
+     * @param <F>     the type parameter
+     * @param factory the factory
+     */
+    public <F extends AbstractFactoryBase> void removeFactoryInstance(Class<F> factory) {
+        if (factory == null) {
+            throw new CoreException(
+                new ErrorCode.ErrorCodeBuilder().withId(ERROR_CODE_E0001).withMessage("Mandatory input factory.")
+                    .withCategory(ErrorCategory.SYSTEM).build());
+        }
+
+        factoryInstanceMap.remove(factory.getName());
+    }
+
+    /**
+     * Stop all.
+     */
+    public void stopAll() {
+        factoryInstanceMap.values().forEach(AbstractFactoryBase::stop);
+    }
+}