feat: address book serializes text hostnames (#12515)

Signed-off-by: Edward Wertz <[email protected]>

Author: edward-swirldslabs

platform-sdk/swirlds-platform-core/src/main/java/com/swirlds/platform/system/address/AddressBookUtils.java

@@ -208,9 +208,11 @@ public static Address parseAddressText(@NonNull final String addressText) throws
         } catch (NumberFormatException e) {
             throw new ParseException("Cannot parse value of weight from '" + parts[4] + "'", 4);
         }
-        final InetAddress internalIp;
+        // FQDN Support: The original string value is preserved, whether it is an IP Address or a FQDN.
+        final String internalHostname = parts[5];
         try {
-            internalIp = InetAddress.getByName(parts[5]);
+            // validate that an InetAddress can be created from the internal hostname.
+            InetAddress.getByName(internalHostname);
         } catch (UnknownHostException e) {
             throw new ParseException("Cannot parse ip address from '" + parts[5] + ",", 5);
         }
@@ -220,9 +222,11 @@ public static Address parseAddressText(@NonNull final String addressText) throws
         } catch (NumberFormatException e) {
             throw new ParseException("Cannot parse ip port from '" + parts[6] + "'", 6);
         }
-        final InetAddress externalIp;
+        // FQDN Support: The original string value is preserved, whether it is an IP Address or a FQDN.
+        final String externalHostname = parts[7];
         try {
-            externalIp = InetAddress.getByName(parts[7]);
+            // validate that an InetAddress can be created from the external hostname.
+            InetAddress.getByName(externalHostname);
         } catch (UnknownHostException e) {
             throw new ParseException("Cannot parse ip address from '" + parts[7] + ",", 7);
         }
@@ -239,9 +243,9 @@ public static Address parseAddressText(@NonNull final String addressText) throws
                 nickname,
                 selfname,
                 weight,
-                internalIp.getHostAddress(),
+                internalHostname,
                 internalPort,
-                externalIp.getHostAddress(),
+                externalHostname,
                 externalPort,
                 memoToUse);
     }

platform-sdk/swirlds-platform-core/src/test/java/com/swirlds/platform/system/address/AddressBookTests.java

@@ -463,6 +463,12 @@ void setNextNodeIdTest() {
     void roundTripSerializeAndDeserializeCompatibleWithConfigTxt() throws ParseException {
         final RandomAddressBookGenerator generator = new RandomAddressBookGenerator(getRandomPrintSeed());
         final AddressBook addressBook = generator.build();
+        // FQDN Support: modify address in address book to have a text based host name.
+        addressBook.add(addressBook
+                .getAddress(addressBook.getNodeId(0))
+                .copySetHostnameInternal("localhost")
+                .copySetHostnameExternal("localhost"));
+
         // make one of the memo fields an empty string
         final NodeId firstNode = addressBook.getNodeId(0);
         addressBook.add(addressBook.getAddress(firstNode).copySetMemo(""));