diff options
Diffstat (limited to 'openecomp-be/lib/openecomp-sdc-logging-lib/openecomp-sdc-logging-core/src/main/java/org/openecomp/sdc/logging/context/HostAddress.java')
-rw-r--r-- | openecomp-be/lib/openecomp-sdc-logging-lib/openecomp-sdc-logging-core/src/main/java/org/openecomp/sdc/logging/context/HostAddress.java | 89 |
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; + } + } +} |