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-rw-r--r--policy-utils/src/main/java/org/onap/policy/drools/utils/OrderedServiceImpl.java135
1 files changed, 0 insertions, 135 deletions
diff --git a/policy-utils/src/main/java/org/onap/policy/drools/utils/OrderedServiceImpl.java b/policy-utils/src/main/java/org/onap/policy/drools/utils/OrderedServiceImpl.java
deleted file mode 100644
index fa0a045c..00000000
--- a/policy-utils/src/main/java/org/onap/policy/drools/utils/OrderedServiceImpl.java
+++ /dev/null
@@ -1,135 +0,0 @@
-/*
- * ============LICENSE_START=======================================================
- * policy-utils
- * ================================================================================
- * Copyright (C) 2017-2018 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.policy.drools.utils;
-
-import java.util.Collections;
-import java.util.HashMap;
-import java.util.LinkedList;
-import java.util.List;
-import java.util.ServiceLoader;
-
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
-/**
- * This class is a template for building a sorted list of service instances,
- * which are discovered and created using 'ServiceLoader'.
- */
-public class OrderedServiceImpl<T extends OrderedService> {
- // logger
- private static Logger logger = LoggerFactory.getLogger(OrderedServiceImpl.class);
-
- // sorted list of instances implementing the service
- private List<T> implementers = null;
-
- // 'ServiceLoader' that is used to discover and create the services
- private ServiceLoader<T> serviceLoader = null;
-
- // use this to ensure that we only use one unique instance of each class
- @SuppressWarnings("rawtypes")
- private static HashMap<Class,OrderedService> classToSingleton = new HashMap<>();
-
- /**
- * Constructor - create the 'ServiceLoader' instance.
- *
- * @param clazz the class object associated with 'T' (I supposed it could
- * be a subclass, but I'm not sure this is useful)
- */
- public OrderedServiceImpl(Class<T> clazz) {
- // This constructor wouldn't be needed if 'T.class' was legal
- serviceLoader = ServiceLoader.load(clazz);
- }
-
- /**
- * Get List of implementers.
- *
- * @return the sorted list of services implementing interface 'T' discovered
- * by 'ServiceLoader'.
- */
- public synchronized List<T> getList() {
- if (implementers == null) {
- rebuildList();
- }
- return implementers;
- }
-
- /**
- * This method is called by 'getList', but could also be called directly if
- * we were running with a 'ClassLoader' that supported the dynamic addition
- * of JAR files. In this case, it could be invoked in order to discover any
- * new services implementing interface 'T'. This is probably a relatively
- * expensive operation in terms of CPU and elapsed time, so it is best if it
- * isn't invoked too frequently.
- *
- * @return the sorted list of services implementing interface 'T' discovered
- * by 'ServiceLoader'.
- */
- @SuppressWarnings("unchecked")
- public synchronized List<T> rebuildList() {
- // build a list of all of the current implementors
- List<T> tmp = new LinkedList<>();
- for (T service : serviceLoader) {
- tmp.add((T)getSingleton(service));
- }
-
- // Sort the list according to sequence number, and then alphabetically
- // according to full class name.
- Collections.sort(tmp, (o1, o2) -> {
- int s1 = o1.getSequenceNumber();
- int s2 = o2.getSequenceNumber();
- if (s1 < s2) {
- return -1;
- } else if (s1 > s2) {
- return 1;
- } else {
- return o1.getClass().getName().compareTo(o2.getClass().getName());
- }
- });
-
- // create an unmodifiable version of this list
- implementers = Collections.unmodifiableList(tmp);
- logger.info("***** OrderedServiceImpl implementers:\n {}", implementers);
- return implementers;
- }
-
- /**
- * If a service implements multiple APIs managed by 'ServiceLoader', a
- * separate instance is created for each API. This method ensures that
- * the first instance is used in all of the lists.
- *
- * @param service this is the object created by ServiceLoader
- * @return the object to use in place of 'service'. If 'service' is the first
- * object of this class created by ServiceLoader, it is returned. If not,
- * the object of this class that was initially created is returned
- * instead.
- */
- private static synchronized OrderedService getSingleton(OrderedService service) {
- // see if we already have an instance of this class
- OrderedService rval = classToSingleton.get(service.getClass());
- if (rval == null) {
- // No previous instance of this class exists -- use the supplied
- // instance, and place it in the table.
- rval = service;
- classToSingleton.put(service.getClass(), service);
- }
- return rval;
- }
-}