Fix issue in UUID-v1 generator on AWS Beanstalk (#1485)

src/main/java/io/ebean/config/ServerConfig.java

@@ -1965,6 +1965,15 @@ public class ServerConfig {
    * Return the UUID state file.
    */
   public String getUuidStateFile() {
+    if (uuidStateFile == null || uuidStateFile.isEmpty()) {
+      // by default, add servername...
+      uuidStateFile = name + "-uuid.state";
+      // and store it in the user's home directory
+      String homeDir = System.getProperty("user.home");
+      if (homeDir != null && homeDir.isEmpty()) {
+        uuidStateFile = homeDir + "/.ebean/" + uuidStateFile;
+      }
+    }
     return uuidStateFile;
   }
 

src/main/java/io/ebeaninternal/server/idgen/UuidV1IdGenerator.java

@@ -82,8 +82,17 @@ public class UuidV1IdGenerator extends UuidV1RndIdGenerator {
     final Enumeration<NetworkInterface> e = NetworkInterface.getNetworkInterfaces();
     while (e.hasMoreElements()) {
       NetworkInterface network = e.nextElement();
-      if (!network.isLoopback()) {
-        return network.getHardwareAddress();
+      try {
+        logger.trace("Probing interface {}", network);
+        if (!network.isLoopback()) {
+          byte[] addr = network.getHardwareAddress();
+          if (addr != null) {
+            logger.debug("Using interface {}", network);
+            return addr;
+          }
+        }
+      } catch (SocketException ex) {
+        logger.debug("Skipping {}", network, ex);
       }
     }
     return null;
@@ -181,6 +190,10 @@ public class UuidV1IdGenerator extends UuidV1RndIdGenerator {
     prop.setProperty("nodeId", getNodeIdentifier());
     prop.setProperty("clockSeq", String.valueOf(clockSeq.get()));
     prop.setProperty("timeStamp", String.valueOf(timeStamp.get()));
+    File dir = stateFile.getParentFile();
+    if (dir != null) {
+      dir.mkdirs();
+    }
     try (OutputStream os = new FileOutputStream(stateFile)) {
       prop.store(os, "ebean uuid state file");
       logger.debug("Persisted state to '{}'", stateFile);