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authorGuo Ruijing <ruijing.guo@intel.com>2017-07-28 08:23:01 +0000
committerGuo Ruijing <ruijing.guo@intel.com>2017-07-28 08:23:30 +0000
commit6abeb297254942c48722c2da0e7c355d523fe307 (patch)
treef2b006ec6ca8804633e2f74a6f1b40c90683f1ea /policy-utils/src/main/java/org/onap
parentd1d749ae390c276fc10c4985d0080f0a9ff7ff35 (diff)
[POLICY-72] replace openecomp for drools-pdp
Change-Id: I8aa8e32d3ba10f7c655b50e97aaf6865514d4777 Signed-off-by: Guo Ruijing <ruijing.guo@intel.com>
Diffstat (limited to 'policy-utils/src/main/java/org/onap')
-rw-r--r--policy-utils/src/main/java/org/onap/policy/drools/utils/OrderedService.java41
-rw-r--r--policy-utils/src/main/java/org/onap/policy/drools/utils/OrderedServiceImpl.java156
-rw-r--r--policy-utils/src/main/java/org/onap/policy/drools/utils/Pair.java51
-rw-r--r--policy-utils/src/main/java/org/onap/policy/drools/utils/PropertyUtil.java385
-rw-r--r--policy-utils/src/main/java/org/onap/policy/drools/utils/ReflectionUtil.java88
-rw-r--r--policy-utils/src/main/java/org/onap/policy/drools/utils/Triple.java45
6 files changed, 766 insertions, 0 deletions
diff --git a/policy-utils/src/main/java/org/onap/policy/drools/utils/OrderedService.java b/policy-utils/src/main/java/org/onap/policy/drools/utils/OrderedService.java
new file mode 100644
index 00000000..75a3cd7d
--- /dev/null
+++ b/policy-utils/src/main/java/org/onap/policy/drools/utils/OrderedService.java
@@ -0,0 +1,41 @@
+/*-
+ * ============LICENSE_START=======================================================
+ * policy-utils
+ * ================================================================================
+ * 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.policy.drools.utils;
+
+/**
+ * This is a base interface that is used to control the order of a list
+ * of services (features) discovered via 'ServiceLoader'. See
+ * 'OrderedServiceImpl' for more details.
+ */
+public interface OrderedService
+{
+ /**
+ * @return an integer sequence number, which determines the order of a list
+ * of objects implementing this interface
+ */
+ public int getSequenceNumber();
+
+
+ /**
+ * @return the name of the ordered service
+ */
+ public default String getName() {return this.getClass().getName();}
+}
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
new file mode 100644
index 00000000..88a53313
--- /dev/null
+++ b/policy-utils/src/main/java/org/onap/policy/drools/utils/OrderedServiceImpl.java
@@ -0,0 +1,156 @@
+/*-
+ * ============LICENSE_START=======================================================
+ * policy-utils
+ * ================================================================================
+ * 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.policy.drools.utils;
+
+import java.util.Collections;
+import java.util.Comparator;
+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; //ServiceLoader.load(T.class);
+
+ /**
+ * 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);
+ }
+
+ /**
+ * @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<T>();
+ 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, new Comparator<T>()
+ {
+ public int compare(T o1, T o2)
+ {
+ int s1 = o1.getSequenceNumber();
+ int s2 = o2.getSequenceNumber();
+ int rval;
+ if (s1 < s2)
+ {
+ rval = -1;
+ }
+ else if (s1 > s2)
+ {
+ rval = 1;
+ }
+ else
+ {
+ rval = o1.getClass().getName().compareTo
+ (o2.getClass().getName());
+ }
+ return(rval);
+ }
+ });
+
+ // create an unmodifiable version of this list
+ implementers = Collections.unmodifiableList(tmp);
+ logger.info("***** OrderedServiceImpl implementers:\n {}", implementers);
+ return(implementers);
+ }
+
+ // use this to ensure that we only use one unique instance of each class
+ @SuppressWarnings("rawtypes")
+ static private HashMap<Class,OrderedService> classToSingleton =
+ new HashMap<>();
+
+ /**
+ * 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.
+ */
+ static private 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);
+ }
+}
diff --git a/policy-utils/src/main/java/org/onap/policy/drools/utils/Pair.java b/policy-utils/src/main/java/org/onap/policy/drools/utils/Pair.java
new file mode 100644
index 00000000..ee0bb6f6
--- /dev/null
+++ b/policy-utils/src/main/java/org/onap/policy/drools/utils/Pair.java
@@ -0,0 +1,51 @@
+/*-
+ * ============LICENSE_START=======================================================
+ * policy-utils
+ * ================================================================================
+ * 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.policy.drools.utils;
+
+public class Pair<F,S> {
+
+ protected F first;
+ protected S second;
+
+ public Pair(F first, S second){
+ this.first = first;
+ this.second = second;
+ }
+
+ public F first() {return this.first;}
+
+ public S second() {return this.second;}
+
+ public F getFirst() {return this.first;}
+
+ public S getSecond() {return this.second;}
+
+ public void first(F first) {this.first = first;}
+
+ public void second(S second) {this.second = second;}
+
+ @Override
+ public String toString() {
+ StringBuilder builder = new StringBuilder();
+ builder.append("Pair [first=").append(first).append(", second=").append(second).append("]");
+ return builder.toString();
+ }
+}
diff --git a/policy-utils/src/main/java/org/onap/policy/drools/utils/PropertyUtil.java b/policy-utils/src/main/java/org/onap/policy/drools/utils/PropertyUtil.java
new file mode 100644
index 00000000..9cfe2ed1
--- /dev/null
+++ b/policy-utils/src/main/java/org/onap/policy/drools/utils/PropertyUtil.java
@@ -0,0 +1,385 @@
+/*-
+ * ============LICENSE_START=======================================================
+ * policy-utils
+ * ================================================================================
+ * 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.policy.drools.utils;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.LinkedList;
+import java.util.Properties;
+import java.util.Set;
+import java.util.Timer;
+import java.util.TimerTask;
+
+/**
+ * This class provides utilities to read properties from a properties
+ * file, and optionally get notifications of future changes
+ */
+public class PropertyUtil
+{
+ /**
+ * Read in a properties file
+ * @param file the properties file
+ * @return a Properties object, containing the associated properties
+ * @throws IOException - subclass 'FileNotFoundException' if the file
+ * does not exist or can't be opened, and 'IOException' if there is
+ * a problem loading the properties file.
+ */
+ static public Properties getProperties(File file) throws IOException
+ {
+ // create an InputStream (may throw a FileNotFoundException)
+ FileInputStream fis = new FileInputStream(file);
+ try
+ {
+ // create the properties instance
+ Properties rval = new Properties();
+
+ // load properties (may throw an IOException)
+ rval.load(fis);
+ return(rval);
+ }
+ finally
+ {
+ // close input stream
+ fis.close();
+ }
+ }
+
+ /**
+ * Read in a properties file
+ * @param fileName the properties file
+ * @return a Properties object, containing the associated properties
+ * @throws IOException - subclass 'FileNotFoundException' if the file
+ * does not exist or can't be opened, and 'IOException' if there is
+ * a problem loading the properties file.
+ */
+ static public Properties getProperties(String fileName) throws IOException
+ {
+ return(getProperties(new File(fileName)));
+ }
+
+ /* ============================================================ */
+
+ // timer thread used for polling for property file changes
+ private static Timer timer = null;
+
+ /**
+ * This is the callback interface, used for sending notifications of
+ * changes in the properties file.
+ */
+ public interface Listener
+ {
+ /**
+ * Notification of a properties file change
+ * @param properties the new properties
+ * @param the set of property names that have changed, including
+ * additions and removals
+ */
+ void propertiesChanged(Properties properties, Set<String> changedKeys);
+ }
+
+ // this table maps canonical file into a 'ListenerRegistration' instance
+ static private HashMap<File, ListenerRegistration> registrations =
+ new HashMap<File, ListenerRegistration>();
+
+ /**
+ * This is an internal class - one instance of this exists for each
+ * property file that is being monitored. Note that multiple listeners
+ * can be registered for the same file.
+ */
+ private static class ListenerRegistration
+ {
+ // the canonical path of the file being monitored
+ File file;
+
+ // the most recent value of 'file.lastModified()'
+ long lastModified;
+
+ // the most recent set of properties
+ Properties properties;
+
+ // the set of listeners monitoring this file
+ LinkedList<Listener> listeners;
+
+ // the 'TimerTask' instance, used for periodic polling
+ TimerTask timerTask;
+
+ /**
+ * Constructor - create a 'ListenerRegistration' instance for this
+ * file, but with no listeners
+ */
+ ListenerRegistration(File file) throws IOException
+ {
+ this.file = file;
+
+ // The initial value of 'lastModified' is set to 0 to ensure that we
+ // correctly handle the case where the file is modified within the
+ // same second that polling begins.
+ lastModified = 0;
+
+ // fetch current properties
+ properties = getProperties(file);
+
+ // no listeners yet
+ listeners = new LinkedList<Listener>();
+
+ // add to static table, so this instance can be shared
+ registrations.put(file, this);
+
+ if (timer == null)
+ {
+ // still need to create a timer thread
+ synchronized(PropertyUtil.class)
+ {
+ // an additional check is added inside the 'synchronized' block,
+ // just in case someone beat us to it
+ if (timer == null)
+ {
+ timer = new Timer("PropertyUtil-Timer", true);
+ }
+ }
+ }
+
+ // create and schedule the timer task, so this is periodically polled
+ timerTask = new TimerTask()
+ {
+ public void run()
+ {
+ try
+ {
+ poll();
+ }
+ catch (Exception e)
+ {
+ System.err.println(e);
+ }
+ }
+ };
+ timer.schedule(timerTask, 10000L, 10000L);
+ }
+
+ /**
+ * Add a listener to the notification list
+ * @param listener this is the listener to add to the list
+ * @return the properties at the moment the listener was added to the list
+ */
+ synchronized Properties addListener(Listener listener)
+ {
+ listeners.add(listener);
+ return((Properties)properties.clone());
+ }
+
+ /**
+ * Remove a listener from the notification list
+ * @param listener this is the listener to remove
+ */
+ synchronized void removeListener(Listener listener)
+ {
+ listeners.remove(listener);
+
+ // See if we need to remove this 'ListenerRegistration' instance
+ // from the table. The 'synchronized' block is needed in case
+ // another listener is being added at about the same time that this
+ // one is being removed.
+ synchronized(registrations)
+ {
+ if (listeners.size() == 0)
+ {
+ timerTask.cancel();
+ registrations.remove(file);
+ }
+ }
+ }
+
+ /**
+ * This method is periodically called to check for property list updates
+ * @throws IOException if there is an error in reading the properties file
+ */
+ synchronized void poll() throws IOException
+ {
+ long timestamp = file.lastModified();
+ if (timestamp != lastModified)
+ {
+ // update the record, and send out the notifications
+ lastModified = timestamp;
+
+ // Save old set, and initial set of changed properties.
+ Properties oldProperties = properties;
+ HashSet<String> changedProperties =
+ new HashSet<String>(oldProperties.stringPropertyNames());
+
+ // Fetch the list of listeners that we will potentially notify,
+ // and the new properties. Note that this is in a 'synchronized'
+ // block to ensure that all listeners receiving notifications
+ // actually have a newer list of properties than the one
+ // returned on the initial 'getProperties' call.
+ properties = getProperties(file);
+
+ Set<String> newPropertyNames = properties.stringPropertyNames();
+ changedProperties.addAll(newPropertyNames);
+
+ // At this point, 'changedProperties' is the union of all properties
+ // in both the old and new properties files. Iterate through all
+ // of the entries in the new properties file - if the entry
+ // matches the one in the old file, remove it from
+ // 'changedProperties'.
+ for (String name : newPropertyNames)
+ {
+ if (properties.getProperty(name).equals
+ (oldProperties.getProperty(name)))
+ {
+ // Apparently, any property that exists must be of type
+ // 'String', and can't be null. For this reason, we don't
+ // need to worry about the case where
+ // 'properties.getProperty(name)' returns 'null'. Note that
+ // 'oldProperties.getProperty(name)' may be 'null' if the
+ // old property does not exist.
+ changedProperties.remove(name);
+ }
+ }
+
+ // 'changedProperties' should be correct at this point
+ if (changedProperties.size() != 0)
+ {
+ // there were changes - notify everyone in 'listeners'
+ for (final Listener notify : listeners)
+ {
+ // Copy 'properties' and 'changedProperties', so it doesn't
+ // cause problems if the recipient makes changes.
+ final Properties tmpProperties =
+ (Properties)(properties.clone());
+ final HashSet<String> tmpChangedProperties =
+ new HashSet<String>(changedProperties);
+
+ // Do the notification in a separate thread, so blocking
+ // won't cause any problems.
+ new Thread()
+ {
+ public void run()
+ {
+ notify.propertiesChanged
+ (tmpProperties, tmpChangedProperties);
+ }
+ }.start();
+ }
+ }
+ }
+ }
+ }
+
+ /**
+ * Read in a properties file, and register for update notifications.
+ * NOTE: it is possible that the first callback will occur while this
+ * method is still in progress. To avoid this problem, use 'synchronized'
+ * blocks around this invocation and in the callback -- that will ensure
+ * that the processing of the initial properties complete before any
+ * updates are processed.
+ *
+ * @param file the properties file
+ * @param notify if not null, this is a callback interface that is used for
+ * notifications of changes
+ * @return a Properties object, containing the associated properties
+ * @throws IOException - subclass 'FileNotFoundException' if the file
+ * does not exist or can't be opened, and 'IOException' if there is
+ * a problem loading the properties file.
+ */
+ static public Properties getProperties(File file, Listener listener)
+ throws IOException
+ {
+ if (listener == null)
+ {
+ // no listener specified -- just fetch the properties
+ return(getProperties(file));
+ }
+
+ // Convert the file to a canonical form in order to avoid the situation
+ // where different names refer to the same file.
+ file = file.getCanonicalFile();
+
+ // See if there is an existing registration. The 'synchronized' block
+ // is needed to handle the case where a new listener is added at about
+ // the same time that another one is being removed.
+ synchronized(registrations)
+ {
+ ListenerRegistration reg = registrations.get(file);
+ if (reg == null)
+ {
+ // a new registration is needed
+ reg = new ListenerRegistration(file);
+ }
+ return(reg.addListener(listener));
+ }
+ }
+
+ /**
+ * Read in a properties file, and register for update notifications.
+ * NOTE: it is possible that the first callback will occur while this
+ * method is still in progress. To avoid this problem, use 'synchronized'
+ * blocks around this invocation and in the callback -- that will ensure
+ * that the processing of the initial properties complete before any
+ * updates are processed.
+ *
+ * @param fileName the properties file
+ * @param notify if not null, this is a callback interface that is used for
+ * notifications of changes
+ * @return a Properties object, containing the associated properties
+ * @throws IOException - subclass 'FileNotFoundException' if the file
+ * does not exist or can't be opened, and 'IOException' if there is
+ * a problem loading the properties file.
+ */
+ static public Properties getProperties(String fileName, Listener listener)
+ throws IOException
+ {
+ return(getProperties(new File(fileName), listener));
+ }
+
+ /**
+ * Stop listenening for updates
+ * @param file the properties file
+ * @param notify if not null, this is a callback interface that was used for
+ * notifications of changes
+ */
+ static public void stopListening(File file, Listener listener)
+ {
+ if (listener != null)
+ {
+ ListenerRegistration reg = registrations.get(file);
+ if (reg != null)
+ {
+ reg.removeListener(listener);
+ }
+ }
+ }
+
+ /**
+ * Stop listenening for updates
+ * @param fileName the properties file
+ * @param notify if not null, this is a callback interface that was used for
+ * notifications of changes
+ */
+ static public void stopListening(String fileName, Listener listener)
+ {
+ stopListening(new File(fileName), listener);
+ }
+
+}
diff --git a/policy-utils/src/main/java/org/onap/policy/drools/utils/ReflectionUtil.java b/policy-utils/src/main/java/org/onap/policy/drools/utils/ReflectionUtil.java
new file mode 100644
index 00000000..eeb7f1f6
--- /dev/null
+++ b/policy-utils/src/main/java/org/onap/policy/drools/utils/ReflectionUtil.java
@@ -0,0 +1,88 @@
+/*-
+ * ============LICENSE_START=======================================================
+ * policy-utils
+ * ================================================================================
+ * 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.policy.drools.utils;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+/**
+ * Reflection utilities
+ *
+ */
+public class ReflectionUtil {
+
+ protected final static Logger logger = LoggerFactory.getLogger(ReflectionUtil.class);
+
+ /**
+ * returns (if exists) a class fetched from a given classloader
+ *
+ * @param classLoader the class loader
+ * @param className the class name
+ * @return the actual class
+ * @throws IllegalArgumentException if an invalid parameter has been passed in
+ */
+ public static Class<?> fetchClass(ClassLoader classLoader,
+ String className)
+ throws IllegalArgumentException {
+ if (classLoader == null)
+ throw new IllegalArgumentException("A class loader must be provided");
+
+ if (className == null)
+ throw new IllegalArgumentException("A class name to be fetched in class loader " +
+ classLoader + " must be provided");
+
+ try {
+ Class<?> aClass = Class.forName(className,
+ true,
+ classLoader);
+ return aClass;
+ } catch (Exception e) {
+ logger.error("FETCHED-CLASS {} IN {} does NOT EXIST", className, classLoader);
+ }
+
+ return null;
+ }
+
+ /**
+ *
+ * @param classLoader target class loader
+ * @param classname class name to fetch
+ * @return true if exists
+ * @throws IllegalArgumentException if an invalid parameter has been passed in
+ */
+ public static boolean isClass(ClassLoader classLoader, String classname)
+ throws IllegalArgumentException {
+ return fetchClass(classLoader, classname) != null;
+ }
+
+ /**
+ * is a subclass?
+ * @param parent superclass
+ * @param presumedSubclass subclass
+ * @return
+ */
+ public static boolean isSubclass(Class<?> parent, Class<?> presumedSubclass) {
+ return (parent.isAssignableFrom(presumedSubclass));
+ }
+
+}
diff --git a/policy-utils/src/main/java/org/onap/policy/drools/utils/Triple.java b/policy-utils/src/main/java/org/onap/policy/drools/utils/Triple.java
new file mode 100644
index 00000000..530d57a5
--- /dev/null
+++ b/policy-utils/src/main/java/org/onap/policy/drools/utils/Triple.java
@@ -0,0 +1,45 @@
+/*-
+ * ============LICENSE_START=======================================================
+ * policy-utils
+ * ================================================================================
+ * 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.policy.drools.utils;
+
+public class Triple<F,S,T> {
+
+ private F first;
+ private S second;
+ private T third;
+
+ public Triple(F first, S second, T third){
+ this.first = first;
+ this.second = second;
+ this.third = third;
+ }
+ public F first(){ return this.first; }
+
+ public S second(){ return this.second; }
+
+ public T third(){ return this.third; }
+
+ public void first(F first){ this.first = first; }
+
+ public void second(S second){ this.second = second; }
+
+ public void third(T third){ this.third = third; }
+}