Adding pdp-common module to policy/common

1) Adding pdp-common module to policy/common. So that all common code
across various pdps will be at one place.
2) Adding java classes for PDP_STATUS, PDP_UPDATE, PDP_STATE_CHANGE &
PDP_HEALTH_CHECK messages.
3) Adding enums for PDPHeathStatus, PDPResponseStatus & PdpState.
4) Adding relevant test cases.

Change-Id: I13e62f393fbd1c261696783cfe4b7dfff72625ba
Issue-ID: POLICY-1443
Signed-off-by: ramverma <ram.krishna.verma@est.tech>

1 files changed, 57 insertions, 0 deletions

diff --git a/pdp-common/src/main/java/org/onap/policy/pdp/common/enums/PdpState.java b/pdp-common/src/main/java/org/onap/policy/pdp/common/enums/PdpState.java
new file mode 100644
index 00000000..88124157
--- /dev/null
+++ b/pdp-common/src/main/java/org/onap/policy/pdp/common/enums/PdpState.java
@@ -0,0 +1,57 @@
+/*-
+ * ============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.onap.policy.pdp.common.enums;
+
+/**
+ * Class to hold the possible values for state of PDP.
+ *
+ * @author Ram Krishna Verma (ram.krishna.verma@est.tech)
+ */
+public enum PdpState {
+
+    /**
+     * Policy execution is always rejected irrespective of PDP type.
+     */
+    PASSIVE,
+
+    /**
+     * Policy execution proceeds, but changes to domain state or context are not carried out. The PDP returns an
+     * indication that it is running in SAFE mode together with the action it would have performed if it was operating
+     * in ACTIVE mode.
+     */
+    SAFE,
+
+    /**
+     * Policy execution proceeds and changes to domain and state are carried out in a test environment. The PDP returns
+     * an indication that it is running in TEST mode together with the action it has performed on the test environment.
+     */
+    TEST,
+
+    /**
+     * Policy execution is executed in the live environment by the PDP.
+     */
+    ACTIVE,
+
+    /**
+     * Policy execution is terminated and not available.
+     */
+    TERMINATED
+}