1 files changed, 89 insertions, 0 deletions
diff --git a/openecomp-be/lib/openecomp-sdc-logging-lib/openecomp-sdc-logging-core/src/main/java/org/openecomp/sdc/logging/context/HostAddress.java b/openecomp-be/lib/openecomp-sdc-logging-lib/openecomp-sdc-logging-core/src/main/java/org/openecomp/sdc/logging/context/HostAddress.java
new file mode 100644
index 0000000000..bcfef6ca01
--- /dev/null
+++ b/openecomp-be/lib/openecomp-sdc-logging-lib/openecomp-sdc-logging-core/src/main/java/org/openecomp/sdc/logging/context/HostAddress.java
@@ -0,0 +1,89 @@
+/*
+ * Copyright © 2016-2018 European Support Limited
+ *
+ * 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.openecomp.sdc.logging.context;
+
+import java.net.InetAddress;
+import java.net.UnknownHostException;
+
+/**
+ * Holds a reference to local host address as returned by Java runtime. A value of host address will be cached for the
+ * interval specified in the constructor or {@link #DEFAULT_REFRESH_INTERVAL}. The caching helps to avoid many low-level
+ * calls, but at the same time pick up any IP or FQDN changes. Although the underlying JDK implementation uses caching
+ * too, the refresh interval for logging may be much longer due to the nature of the use.
+ *
+ * @author evitaliy
+ * @since 26 Mar 2018
+ */
+@SuppressWarnings({"UseOfSystemOutOrSystemErr", "CallToPrintStackTrace", "squid:S106", "squid:S1148"})
+public class HostAddress {
+
+    private static final long DEFAULT_REFRESH_INTERVAL = 60000L; // 1 min
+
+    private final long interval;
+
+    private CacheEntry cachedAddress;
+
+    public HostAddress() {
+        this(DEFAULT_REFRESH_INTERVAL);
+    }
+
+    /**
+     * Creates a cache for host address with a custom refresh interval.
+     */
+    public HostAddress(long refreshInterval) {
+        this.interval = refreshInterval;
+        this.cachedAddress = new CacheEntry(System.currentTimeMillis(), read());
+    }
+
+    /**
+     * Returns an address (host name and IP address) of the local system.
+     *
+     * @return local host address or <code>null</code> if it could not be read for some reason
+     */
+    public synchronized InetAddress get() {
+
+        long current = System.currentTimeMillis();
+        if (current - cachedAddress.lastUpdated < interval) {
+            return cachedAddress.address;
+        }
+
+        InetAddress address = read();
+        cachedAddress = new CacheEntry(current, address);
+        return address;
+    }
+
+    private InetAddress read() {
+
+        try {
+            return InetAddress.getLocalHost();
+        } catch (UnknownHostException e) {
+            e.printStackTrace(); // can't really use logging
+            return null; // let register the attempt even if failed
+        }
+    }
+
+    private static class CacheEntry {
+
+        private final long lastUpdated;
+        private final InetAddress address;
+
+        private CacheEntry(long lastUpdated, InetAddress address) {
+            this.lastUpdated = lastUpdated;
+            this.address = address;
+        }
+    }
+}