PortUtil fixes from my working branch to avoid test failures

hapi-fhir-base/src/main/java/ca/uhn/fhir/util/PortUtil.java

@@ -217,28 +217,20 @@ public class PortUtil {
 	}
 
 	private static boolean isAvailable(int port) {
-		ServerSocket ss = null;
-		DatagramSocket ds = null;
-		try {
-			ss = new ServerSocket(port);
+		ourLog.info("Testing a bind on port {}", port);
+		try (ServerSocket ss = new ServerSocket(port)) {
 			ss.setReuseAddress(true);
-			ds = new DatagramSocket(port);
+			try (DatagramSocket ds = new DatagramSocket(port)) {
 				ds.setReuseAddress(true);
+				ourLog.info("Successfully bound port {}", port);
 				return true;
 			} catch (IOException e) {
+				ourLog.info("Failed to bind port {}: {}", port, e.toString());
 				return false;
-		} finally {
-			if (ds != null) {
-				ds.close();
 			}
-
-			if (ss != null) {
-				try {
-					ss.close();
 		} catch (IOException e) {
-					/* should not be thrown */
-				}
-			}
+			ourLog.info("Failed to bind port {}: {}", port, e.toString());
+			return false;
 		}
 	}
 

hapi-fhir-base/src/test/java/ca/uhn/fhir/util/PortUtilTest.java

@@ -63,13 +63,23 @@ public class PortUtilTest {
 				for (int j = 0; j < portsPerTaskCount; j++) {
 					int nextFreePort = portUtil.getNextFreePort();
 
+					boolean bound;
 					try (ServerSocket ss = new ServerSocket()) {
 						ss.bind(new InetSocketAddress("localhost", nextFreePort));
+						bound = true;
 					} catch (IOException e) {
-						String msg = "Failure binding new port " + nextFreePort + ": " + e.toString();
+						bound = false;
+					}
+
+					if (!bound) {
+						try (ServerSocket ss = new ServerSocket()) {
+							Thread.sleep(1000);
+							ss.bind(new InetSocketAddress("localhost", nextFreePort));
+						} catch (Exception e) {
+							String msg = "Failure binding new port (second attempt) " + nextFreePort + ": " + e.toString();
 							ourLog.error(msg, e);
 							errors.add(msg);
-
+						}
 					}
 
 					ports.add(nextFreePort);