ARTEMIS-2395 empty address.txt causes NPE

artemis-server/src/main/java/org/apache/activemq/artemis/core/paging/impl/PagingStoreFactoryNIO.java

@@ -56,7 +56,7 @@ public class PagingStoreFactoryNIO implements PagingStoreFactory {
 
    // Constants -----------------------------------------------------
 
-   private static final String ADDRESS_FILE = "address.txt";
+   public static final String ADDRESS_FILE = "address.txt";
 
    // Attributes ----------------------------------------------------
 
@@ -217,6 +217,12 @@ public List<PagingStore> reloadStores(final HierarchicalRepository<AddressSettin
                addressString = reader.readLine();
             }
 
+            // there's no address listed in the file so we just skip it
+            if (addressString == null) {
+               ActiveMQServerLogger.LOGGER.emptyAddressFile(PagingStoreFactoryNIO.ADDRESS_FILE, file.toString());
+               continue;
+            }
+
             SimpleString address = new SimpleString(addressString);
 
             SequentialFileFactory factory = newFileFactory(guid);

artemis-server/src/main/java/org/apache/activemq/artemis/core/server/ActiveMQServerLogger.java

@@ -1629,6 +1629,11 @@ void slowConsumerDetected(String sessionID,
    @Message(id = 222281, value = "Federation upstream {0} policy ref {1} are too self referential, avoiding stack overflow , ", format = Message.Format.MESSAGE_FORMAT)
    void federationAvoidStackOverflowPolicyRef(String upstreamName, String policyRef);
 
+   @LogMessage(level = Logger.Level.WARN)
+   @Message(id = 222282, value = "File {0} at {1} is empty. Delete the empty file to stop this message.",
+      format = Message.Format.MESSAGE_FORMAT)
+   void emptyAddressFile(String addressFile, String directory);
+
    @LogMessage(level = Logger.Level.ERROR)
    @Message(id = 224000, value = "Failure in initialisation", format = Message.Format.MESSAGE_FORMAT)
    void initializationError(@Cause Throwable e);

tests/integration-tests/src/test/java/org/apache/activemq/artemis/tests/integration/paging/PagingTest.java

@@ -25,6 +25,7 @@
 import java.io.File;
 import java.io.IOException;
 import java.io.OutputStream;
+import java.io.PrintWriter;
 import java.lang.management.ManagementFactory;
 import java.nio.ByteBuffer;
 import java.util.ArrayList;
@@ -491,6 +492,70 @@ public void testPageCleanup() throws Exception {
       System.out.println("pgComplete = " + pgComplete);
    }
 
+   @Test
+   public void testEmptyAddress() throws Exception {
+      if (storeType == StoreConfiguration.StoreType.FILE) {
+         clearDataRecreateServerDirs();
+
+         Configuration config = createDefaultInVMConfig().setJournalSyncNonTransactional(false);
+
+         server = createServer(true, config, PagingTest.PAGE_SIZE, PagingTest.PAGE_MAX);
+
+         server.start();
+
+         final int numberOfMessages = 5000;
+
+         locator = createInVMNonHALocator().setBlockOnNonDurableSend(true).setBlockOnDurableSend(true).setBlockOnAcknowledge(true);
+
+         sf = createSessionFactory(locator);
+
+         ClientSession session = sf.createSession(false, false, false);
+
+         session.createQueue(PagingTest.ADDRESS, RoutingType.ANYCAST, PagingTest.ADDRESS, null, true);
+
+         ClientProducer producer = session.createProducer(PagingTest.ADDRESS);
+
+         byte[] body = new byte[MESSAGE_SIZE];
+
+         ByteBuffer bb = ByteBuffer.wrap(body);
+
+         for (int j = 1; j <= MESSAGE_SIZE; j++) {
+            bb.put(getSamplebyte(j));
+         }
+
+         for (int i = 0; i < numberOfMessages; i++) {
+            ClientMessage message = session.createMessage(true);
+
+            message.getBodyBuffer().writeBytes(body);
+
+            producer.send(message);
+            if (i % 1000 == 0) {
+               session.commit();
+            }
+         }
+         session.commit();
+         producer.close();
+         session.close();
+
+         String addressTxt = server.getPagingManager().getPageStore(PagingTest.ADDRESS).getFolder().getAbsolutePath() + File.separator + PagingStoreFactoryNIO.ADDRESS_FILE;
+
+         server.stop();
+
+         // delete contents of address.txt
+         new PrintWriter(addressTxt).close();
+
+         final AtomicBoolean activationFailures = new AtomicBoolean();
+
+         server.registerActivationFailureListener(exception -> activationFailures.set(true));
+
+         server.start();
+
+         server.stop();
+
+         assertFalse(activationFailures.get());
+      }
+   }
+
    @Test
    public void testPurge() throws Exception {
       clearDataRecreateServerDirs();