Add DroolsExecutor for DroolsRunnable

Added DroolsExecutor, which is an Executor that works by injecting
its commands into drools working memory via DroolsRunnable objects.

Issue-ID: POLICY-2385
Signed-off-by: Jim Hahn <jrh3@att.com>
Change-Id: I59a57bc431249c84cb08f87089f6239993d7d2c4

1 files changed, 47 insertions, 0 deletions

diff --git a/policy-core/src/main/java/org/onap/policy/drools/core/DroolsExecutor.java b/policy-core/src/main/java/org/onap/policy/drools/core/DroolsExecutor.java
new file mode 100644
index 00000000..538970d6
--- /dev/null
+++ b/policy-core/src/main/java/org/onap/policy/drools/core/DroolsExecutor.java
@@ -0,0 +1,47 @@
+/*-
+ * ============LICENSE_START=======================================================
+ * ONAP
+ * ================================================================================
+ * Copyright (C) 2020 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.core;
+
+import java.util.concurrent.Executor;
+import org.drools.core.WorkingMemory;
+
+/**
+ * An executor that executes its tasks by inserting {@link DroolsRunnable} objects into
+ * the working memory of a running session.
+ */
+public class DroolsExecutor implements Executor {
+    private final WorkingMemory workingMemory;
+
+    /**
+     * Constructs the object.
+     *
+     * @param workingMemory where tasks should be injected
+     */
+    public DroolsExecutor(WorkingMemory workingMemory) {
+        this.workingMemory = workingMemory;
+    }
+
+    @Override
+    public void execute(Runnable command) {
+        DroolsRunnable runnable = command::run;
+        workingMemory.insert(runnable);
+    }
+}