Merge changes Idbdec7b3,I643dadac,I2f54e1d5,I2ead5203

* changes:
  Provide initial a1-pe-sim docs
  Initial code check-in for A1 Policy Enforcement Simulator
  Add basic .gitignore
  Add linters setup

1 files changed, 71 insertions, 0 deletions

diff --git a/src/main/java/org/onap/a1pesimulator/util/TopologyReader.java b/src/main/java/org/onap/a1pesimulator/util/TopologyReader.java
new file mode 100644
index 0000000..55e47cf
--- /dev/null
+++ b/src/main/java/org/onap/a1pesimulator/util/TopologyReader.java
@@ -0,0 +1,71 @@
+/*
+ * Copyright (C) 2021 Samsung Electronics
+ * 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
+ */
+
+package org.onap.a1pesimulator.util;
+
+import java.io.File;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.Collections;
+import org.onap.a1pesimulator.data.cell.CellList;
+import org.onap.a1pesimulator.data.ue.UserEquipment;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.stereotype.Service;
+
+@Service
+public class TopologyReader {
+
+    private final String topologyCellConfigFile;
+    private final String topologyUeConfigFile;
+
+    private long topologyCellLastModified = 0L;
+    private long topologyUeLastModified = 0L;
+
+    private TopologyReader(@Value("${topology.cell.config.file}") final String topologyCellConfigFile,
+            @Value("${topology.ue.config.file}") final String topologyUeConfigFile) {
+        this.topologyCellConfigFile = topologyCellConfigFile;
+        this.topologyUeConfigFile = topologyUeConfigFile;
+    }
+
+    public CellList loadCellTopology() {
+        final File file = new File(topologyCellConfigFile);
+        topologyCellLastModified = file.lastModified();
+
+        if (!file.exists()) {
+            return new CellList();
+        }
+
+        return JsonUtils.INSTANCE.deserializeFromFile(topologyCellConfigFile, CellList.class);
+    }
+
+    public Collection<UserEquipment> loadUeTopology() {
+        final File file = new File(topologyUeConfigFile);
+        topologyUeLastModified = file.lastModified();
+
+        if (!file.exists()) {
+            return Collections.emptyList();
+        }
+
+        final UserEquipment[] userEquipments =
+                JsonUtils.INSTANCE.deserializeFromFile(topologyUeConfigFile, UserEquipment[].class);
+        return Arrays.asList(userEquipments);
+    }
+
+    public boolean topologyCellHasChanged() {
+        return topologyCellLastModified != new File(topologyCellConfigFile).lastModified();
+    }
+
+    public boolean topologyUeHasChanged() {
+        return topologyUeLastModified != new File(topologyUeConfigFile).lastModified();
+    }
+}