1 files changed, 44 insertions, 9 deletions

diff --git a/policy-utils/src/main/java/org/onap/policy/drools/utils/NetworkUtil.java b/policy-utils/src/main/java/org/onap/policy/drools/utils/NetworkUtil.java
index f6c837f5..bd5b8aac 100644
--- a/policy-utils/src/main/java/org/onap/policy/drools/utils/NetworkUtil.java
+++ b/policy-utils/src/main/java/org/onap/policy/drools/utils/NetworkUtil.java
@@ -7,9 +7,9 @@
  * 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.
@@ -20,16 +20,51 @@
 
 package org.onap.policy.drools.utils;
 
+import java.io.IOException;
+import java.net.ConnectException;
+import java.net.Socket;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
 /**
  * Network Utilities
  */
 public class NetworkUtil {
-	
-	/**
-	 * IPv4 Wildcard IP address
-	 */
-	public static final String IPv4_WILDCARD_ADDRESS = "0.0.0.0";
-	
-	/* Other methods will be added as needed */
+
+  public static final Logger logger = LoggerFactory.getLogger(NetworkUtil.class.getName());
+
+  /**
+   * IPv4 Wildcard IP address
+   */
+  public static final String IPv4_WILDCARD_ADDRESS = "0.0.0.0";
+
+
+  /**
+   * try to connect to $host:$port $retries times while we are getting connection failures.
+   *
+   * @param host host
+   * @param port port
+   * @param retries number of attempts
+   * @return true is port is open, false otherwise
+   * @throws InterruptedException if execution has been interrupted
+   */
+  public static boolean isTcpPortOpen(String host, int port, int retries, long interval)
+      throws InterruptedException, IOException {
+    int retry = 0;
+    while (retry < retries) {
+      try (Socket s = new Socket(host, port)) {
+        logger.debug("{}:{} connected - retries={} interval={}", host, port, retries, interval);
+        return true;
+      } catch (final ConnectException e) {
+        retry++;
+        logger.trace("{}:{} connected - retries={} interval={}", host, port, retries, interval, e);
+        Thread.sleep(interval);
+      }
+    }
+
+    logger.warn("{}:{} closed = retries={} interval={}", host, port, retries, interval);
+    return false;
+  }
 
 }