diff --git a/smack-core/src/main/java/org/jivesoftware/smack/AbstractConnectionClosedListener.java b/smack-core/src/main/java/org/jivesoftware/smack/AbstractConnectionClosedListener.java
index 35302efa1..f1f87fbdb 100644
--- a/smack-core/src/main/java/org/jivesoftware/smack/AbstractConnectionClosedListener.java
+++ b/smack-core/src/main/java/org/jivesoftware/smack/AbstractConnectionClosedListener.java
@@ -1,6 +1,6 @@
 /**
  *
- * Copyright 2015 Florian Schmaus
+ * Copyright 2015-2020 Florian Schmaus
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,7 +16,7 @@
  */
 package org.jivesoftware.smack;
 
-public abstract class AbstractConnectionClosedListener extends AbstractConnectionListener {
+public abstract class AbstractConnectionClosedListener implements ConnectionListener {
 
     @Override
     public final void connectionClosed() {
diff --git a/smack-core/src/main/java/org/jivesoftware/smack/AbstractConnectionListener.java b/smack-core/src/main/java/org/jivesoftware/smack/AbstractConnectionListener.java
index 19847598c..f4a6749b9 100644
--- a/smack-core/src/main/java/org/jivesoftware/smack/AbstractConnectionListener.java
+++ b/smack-core/src/main/java/org/jivesoftware/smack/AbstractConnectionListener.java
@@ -23,7 +23,10 @@ package org.jivesoftware.smack;
  * all methods.
  *
  * @author Henning Staib
+ * @deprecated use {@link ConnectionListener} instead.
  */
+// TODO: Remove in Smack 4.5.
+@Deprecated
 public class AbstractConnectionListener implements ConnectionListener {
     @Override
     public void connected(XMPPConnection connection) {
diff --git a/smack-core/src/main/java/org/jivesoftware/smack/ConnectionListener.java b/smack-core/src/main/java/org/jivesoftware/smack/ConnectionListener.java
index 716b4c1d2..3e85191b9 100644
--- a/smack-core/src/main/java/org/jivesoftware/smack/ConnectionListener.java
+++ b/smack-core/src/main/java/org/jivesoftware/smack/ConnectionListener.java
@@ -37,7 +37,8 @@ public interface ConnectionListener {
      *
      * @param connection the XMPPConnection which successfully connected to its endpoint.
      */
-    void connected(XMPPConnection connection);
+    default void connected(XMPPConnection connection) {
+    }
 
     /**
      * Notification that the connection has been authenticated.
@@ -45,12 +46,14 @@ public interface ConnectionListener {
      * @param connection the XMPPConnection which successfully authenticated.
      * @param resumed true if a previous XMPP session's stream was resumed.
      */
-    void authenticated(XMPPConnection connection, boolean resumed);
+    default void authenticated(XMPPConnection connection, boolean resumed) {
+    }
 
     /**
      * Notification that the connection was closed normally.
      */
-    void connectionClosed();
+    default void connectionClosed() {
+    }
 
     /**
      * Notification that the connection was closed due to an exception. When
@@ -59,6 +62,7 @@ public interface ConnectionListener {
      *
      * @param e the exception.
      */
-    void connectionClosedOnError(Exception e);
+    default void connectionClosedOnError(Exception e) {
+    }
 
 }
diff --git a/smack-core/src/main/java/org/jivesoftware/smack/ReconnectionManager.java b/smack-core/src/main/java/org/jivesoftware/smack/ReconnectionManager.java
index b06916117..de50dce0c 100644
--- a/smack-core/src/main/java/org/jivesoftware/smack/ReconnectionManager.java
+++ b/smack-core/src/main/java/org/jivesoftware/smack/ReconnectionManager.java
@@ -401,7 +401,7 @@ public final class ReconnectionManager {
         reconnectionThread = null;
     }
 
-    private final ConnectionListener connectionListener = new AbstractConnectionListener() {
+    private final ConnectionListener connectionListener = new ConnectionListener() {
 
         @Override
         public void connectionClosed() {
diff --git a/smack-core/src/main/java/org/jivesoftware/smack/debugger/AbstractDebugger.java b/smack-core/src/main/java/org/jivesoftware/smack/debugger/AbstractDebugger.java
index ad252e86c..4848c8c5b 100644
--- a/smack-core/src/main/java/org/jivesoftware/smack/debugger/AbstractDebugger.java
+++ b/smack-core/src/main/java/org/jivesoftware/smack/debugger/AbstractDebugger.java
@@ -18,7 +18,6 @@ package org.jivesoftware.smack.debugger;
 
 import java.util.logging.Logger;
 
-import org.jivesoftware.smack.AbstractConnectionListener;
 import org.jivesoftware.smack.AbstractXMPPConnection;
 import org.jivesoftware.smack.ConnectionListener;
 import org.jivesoftware.smack.ReconnectionListener;
@@ -69,7 +68,7 @@ public abstract class AbstractDebugger extends SmackDebugger {
         };
         this.writer.addWriterListener(writerListener);
 
-        connListener = new AbstractConnectionListener() {
+        connListener = new ConnectionListener() {
             @Override
             public void connected(XMPPConnection connection) {
                 log("XMPPConnection connected ("
diff --git a/smack-debug-slf4j/src/main/java/org/jivesoftware/smackx/debugger/slf4j/SLF4JLoggingConnectionListener.java b/smack-debug-slf4j/src/main/java/org/jivesoftware/smackx/debugger/slf4j/SLF4JLoggingConnectionListener.java
index d92efd866..d3301a2e5 100644
--- a/smack-debug-slf4j/src/main/java/org/jivesoftware/smackx/debugger/slf4j/SLF4JLoggingConnectionListener.java
+++ b/smack-debug-slf4j/src/main/java/org/jivesoftware/smackx/debugger/slf4j/SLF4JLoggingConnectionListener.java
@@ -17,13 +17,13 @@
 
 package org.jivesoftware.smackx.debugger.slf4j;
 
-import org.jivesoftware.smack.AbstractConnectionListener;
+import org.jivesoftware.smack.ConnectionListener;
 import org.jivesoftware.smack.ReconnectionListener;
 import org.jivesoftware.smack.XMPPConnection;
 
 import org.slf4j.Logger;
 
-class SLF4JLoggingConnectionListener extends AbstractConnectionListener implements ReconnectionListener {
+class SLF4JLoggingConnectionListener implements ConnectionListener, ReconnectionListener {
     private final XMPPConnection connection;
     private final Logger logger;
 
diff --git a/smack-debug/src/main/java/org/jivesoftware/smackx/debugger/EnhancedDebugger.java b/smack-debug/src/main/java/org/jivesoftware/smackx/debugger/EnhancedDebugger.java
index c30f0aaf4..c4a8c90dd 100644
--- a/smack-debug/src/main/java/org/jivesoftware/smackx/debugger/EnhancedDebugger.java
+++ b/smack-debug/src/main/java/org/jivesoftware/smackx/debugger/EnhancedDebugger.java
@@ -60,7 +60,6 @@ import javax.swing.event.ListSelectionListener;
 import javax.swing.table.DefaultTableModel;
 import javax.swing.text.BadLocationException;
 
-import org.jivesoftware.smack.AbstractConnectionListener;
 import org.jivesoftware.smack.AbstractXMPPConnection;
 import org.jivesoftware.smack.ConnectionListener;
 import org.jivesoftware.smack.ReconnectionListener;
@@ -220,7 +219,7 @@ public class EnhancedDebugger extends SmackDebugger {
         addInformationPanel();
 
         // Create a thread that will listen for any connection closed event
-        connListener = new AbstractConnectionListener() {
+        connListener = new ConnectionListener() {
             @Override
             public void connectionClosed() {
                 SwingUtilities.invokeLater(new Runnable() {
diff --git a/smack-experimental/src/main/java/org/jivesoftware/smackx/carbons/CarbonManager.java b/smack-experimental/src/main/java/org/jivesoftware/smackx/carbons/CarbonManager.java
index ab41a432c..5e943efc0 100644
--- a/smack-experimental/src/main/java/org/jivesoftware/smackx/carbons/CarbonManager.java
+++ b/smack-experimental/src/main/java/org/jivesoftware/smackx/carbons/CarbonManager.java
@@ -1,6 +1,6 @@
 /**
  *
- * Copyright 2013-2014 Georg Lukas, 2017-2018 Florian Schmaus
+ * Copyright 2013-2014 Georg Lukas, 2017-2020 Florian Schmaus
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -21,9 +21,9 @@ import java.util.Set;
 import java.util.WeakHashMap;
 import java.util.concurrent.CopyOnWriteArraySet;
 
-import org.jivesoftware.smack.AbstractConnectionListener;
 import org.jivesoftware.smack.AsyncButOrdered;
 import org.jivesoftware.smack.ConnectionCreationListener;
+import org.jivesoftware.smack.ConnectionListener;
 import org.jivesoftware.smack.Manager;
 import org.jivesoftware.smack.SmackException;
 import org.jivesoftware.smack.SmackException.NoResponseException;
@@ -130,7 +130,7 @@ public final class CarbonManager extends Manager {
             }
         };
 
-        connection.addConnectionListener(new AbstractConnectionListener() {
+        connection.addConnectionListener(new ConnectionListener() {
             @Override
             public void connectionClosed() {
                 // Reset the state if the connection was cleanly closed. Note that this is not strictly necessary,
diff --git a/smack-experimental/src/main/java/org/jivesoftware/smackx/httpfileupload/HttpFileUploadManager.java b/smack-experimental/src/main/java/org/jivesoftware/smackx/httpfileupload/HttpFileUploadManager.java
index eadbaff94..299466bbb 100644
--- a/smack-experimental/src/main/java/org/jivesoftware/smackx/httpfileupload/HttpFileUploadManager.java
+++ b/smack-experimental/src/main/java/org/jivesoftware/smackx/httpfileupload/HttpFileUploadManager.java
@@ -37,9 +37,9 @@ import javax.net.ssl.HttpsURLConnection;
 import javax.net.ssl.SSLContext;
 import javax.net.ssl.SSLSocketFactory;
 
-import org.jivesoftware.smack.AbstractConnectionListener;
 import org.jivesoftware.smack.ConnectionConfiguration;
 import org.jivesoftware.smack.ConnectionCreationListener;
+import org.jivesoftware.smack.ConnectionListener;
 import org.jivesoftware.smack.Manager;
 import org.jivesoftware.smack.SmackException;
 import org.jivesoftware.smack.XMPPConnection;
@@ -118,7 +118,7 @@ public final class HttpFileUploadManager extends Manager {
     private HttpFileUploadManager(XMPPConnection connection) {
         super(connection);
 
-        connection.addConnectionListener(new AbstractConnectionListener() {
+        connection.addConnectionListener(new ConnectionListener() {
             @Override
             public void authenticated(XMPPConnection connection, boolean resumed) {
                 // No need to reset the cache if the connection got resumed.
diff --git a/smack-extensions/src/main/java/org/jivesoftware/smackx/blocking/BlockingCommandManager.java b/smack-extensions/src/main/java/org/jivesoftware/smackx/blocking/BlockingCommandManager.java
index 24febb821..fef15db1f 100644
--- a/smack-extensions/src/main/java/org/jivesoftware/smackx/blocking/BlockingCommandManager.java
+++ b/smack-extensions/src/main/java/org/jivesoftware/smackx/blocking/BlockingCommandManager.java
@@ -1,6 +1,6 @@
 /**
  *
- * Copyright 2016-2017 Fernando Ramirez, Florian Schmaus
+ * Copyright 2016-2017 Fernando Ramirez, 2016-2020 Florian Schmaus
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -24,8 +24,8 @@ import java.util.Set;
 import java.util.WeakHashMap;
 import java.util.concurrent.CopyOnWriteArraySet;
 
-import org.jivesoftware.smack.AbstractConnectionListener;
 import org.jivesoftware.smack.ConnectionCreationListener;
+import org.jivesoftware.smack.ConnectionListener;
 import org.jivesoftware.smack.Manager;
 import org.jivesoftware.smack.SmackException.NoResponseException;
 import org.jivesoftware.smack.SmackException.NotConnectedException;
@@ -145,7 +145,7 @@ public final class BlockingCommandManager extends Manager {
             }
         });
 
-        connection.addConnectionListener(new AbstractConnectionListener() {
+        connection.addConnectionListener(new ConnectionListener() {
             @Override
             public void authenticated(XMPPConnection connection, boolean resumed) {
                 // No need to reset the cache if the connection got resumed.
diff --git a/smack-extensions/src/main/java/org/jivesoftware/smackx/caps/EntityCapsManager.java b/smack-extensions/src/main/java/org/jivesoftware/smackx/caps/EntityCapsManager.java
index 5407d11e3..d7ee5b45a 100644
--- a/smack-extensions/src/main/java/org/jivesoftware/smackx/caps/EntityCapsManager.java
+++ b/smack-extensions/src/main/java/org/jivesoftware/smackx/caps/EntityCapsManager.java
@@ -36,8 +36,8 @@ import java.util.concurrent.ConcurrentLinkedQueue;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
-import org.jivesoftware.smack.AbstractConnectionListener;
 import org.jivesoftware.smack.ConnectionCreationListener;
+import org.jivesoftware.smack.ConnectionListener;
 import org.jivesoftware.smack.Manager;
 import org.jivesoftware.smack.SmackConfiguration;
 import org.jivesoftware.smack.SmackException.NoResponseException;
@@ -328,7 +328,7 @@ public final class EntityCapsManager extends Manager {
         this.sdm = ServiceDiscoveryManager.getInstanceFor(connection);
         instances.put(connection, this);
 
-        connection.addConnectionListener(new AbstractConnectionListener() {
+        connection.addConnectionListener(new ConnectionListener() {
             @Override
             public void connected(XMPPConnection connection) {
                 // It's not clear when a server would report the caps stream
diff --git a/smack-extensions/src/main/java/org/jivesoftware/smackx/jingle/transports/JingleTransportManager.java b/smack-extensions/src/main/java/org/jivesoftware/smackx/jingle/transports/JingleTransportManager.java
index bfc0d1a5d..5b348c5d3 100644
--- a/smack-extensions/src/main/java/org/jivesoftware/smackx/jingle/transports/JingleTransportManager.java
+++ b/smack-extensions/src/main/java/org/jivesoftware/smackx/jingle/transports/JingleTransportManager.java
@@ -16,7 +16,7 @@
  */
 package org.jivesoftware.smackx.jingle.transports;
 
-import org.jivesoftware.smack.AbstractConnectionListener;
+import org.jivesoftware.smack.ConnectionListener;
 import org.jivesoftware.smack.XMPPConnection;
 
 import org.jivesoftware.smackx.jingle.JingleSession;
@@ -26,7 +26,7 @@ import org.jivesoftware.smackx.jingle.element.JingleContentTransport;
  * Manager for a JingleTransport method.
  * @param <D> JingleContentTransport.
  */
-public abstract class JingleTransportManager<D extends JingleContentTransport> extends AbstractConnectionListener {
+public abstract class JingleTransportManager<D extends JingleContentTransport> implements ConnectionListener {
 
     private final XMPPConnection connection;
 
diff --git a/smack-extensions/src/main/java/org/jivesoftware/smackx/muc/MultiUserChatManager.java b/smack-extensions/src/main/java/org/jivesoftware/smackx/muc/MultiUserChatManager.java
index 1a29ebe91..e2654de89 100644
--- a/smack-extensions/src/main/java/org/jivesoftware/smackx/muc/MultiUserChatManager.java
+++ b/smack-extensions/src/main/java/org/jivesoftware/smackx/muc/MultiUserChatManager.java
@@ -1,6 +1,6 @@
 /**
  *
- * Copyright © 2014-2019 Florian Schmaus
+ * Copyright © 2014-2020 Florian Schmaus
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -28,8 +28,8 @@ import java.util.concurrent.CopyOnWriteArraySet;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
-import org.jivesoftware.smack.AbstractConnectionListener;
 import org.jivesoftware.smack.ConnectionCreationListener;
+import org.jivesoftware.smack.ConnectionListener;
 import org.jivesoftware.smack.Manager;
 import org.jivesoftware.smack.SmackException.NoResponseException;
 import org.jivesoftware.smack.SmackException.NotConnectedException;
@@ -191,7 +191,7 @@ public final class MultiUserChatManager extends Manager {
         };
         connection.addAsyncStanzaListener(invitationPacketListener, INVITATION_FILTER);
 
-        connection.addConnectionListener(new AbstractConnectionListener() {
+        connection.addConnectionListener(new ConnectionListener() {
             @Override
             public void authenticated(XMPPConnection connection, boolean resumed) {
                 if (resumed) return;
diff --git a/smack-extensions/src/main/java/org/jivesoftware/smackx/muc/bookmarkautojoin/MucBookmarkAutojoinManager.java b/smack-extensions/src/main/java/org/jivesoftware/smackx/muc/bookmarkautojoin/MucBookmarkAutojoinManager.java
index fa4abeb09..30e807854 100644
--- a/smack-extensions/src/main/java/org/jivesoftware/smackx/muc/bookmarkautojoin/MucBookmarkAutojoinManager.java
+++ b/smack-extensions/src/main/java/org/jivesoftware/smackx/muc/bookmarkautojoin/MucBookmarkAutojoinManager.java
@@ -1,6 +1,6 @@
 /**
  *
- * Copyright © 2015 Florian Schmaus
+ * Copyright © 2015-2020 Florian Schmaus
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -22,8 +22,8 @@ import java.util.WeakHashMap;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
-import org.jivesoftware.smack.AbstractConnectionListener;
 import org.jivesoftware.smack.ConnectionCreationListener;
+import org.jivesoftware.smack.ConnectionListener;
 import org.jivesoftware.smack.Manager;
 import org.jivesoftware.smack.SmackException.NoResponseException;
 import org.jivesoftware.smack.SmackException.NotConnectedException;
@@ -85,7 +85,7 @@ public final class MucBookmarkAutojoinManager extends Manager {
         super(connection);
         multiUserChatManager = MultiUserChatManager.getInstanceFor(connection);
         bookmarkManager = BookmarkManager.getBookmarkManager(connection);
-        connection.addConnectionListener(new AbstractConnectionListener() {
+        connection.addConnectionListener(new ConnectionListener() {
             @Override
             public void authenticated(XMPPConnection connection, boolean resumed) {
                 if (!autojoinEnabled) {
diff --git a/smack-extensions/src/main/java/org/jivesoftware/smackx/privacy/PrivacyListManager.java b/smack-extensions/src/main/java/org/jivesoftware/smackx/privacy/PrivacyListManager.java
index bf40cc8e6..362ed8e71 100644
--- a/smack-extensions/src/main/java/org/jivesoftware/smackx/privacy/PrivacyListManager.java
+++ b/smack-extensions/src/main/java/org/jivesoftware/smackx/privacy/PrivacyListManager.java
@@ -23,8 +23,8 @@ import java.util.Set;
 import java.util.WeakHashMap;
 import java.util.concurrent.CopyOnWriteArraySet;
 
-import org.jivesoftware.smack.AbstractConnectionListener;
 import org.jivesoftware.smack.ConnectionCreationListener;
+import org.jivesoftware.smack.ConnectionListener;
 import org.jivesoftware.smack.Manager;
 import org.jivesoftware.smack.SmackException.NoResponseException;
 import org.jivesoftware.smack.SmackException.NotConnectedException;
@@ -186,7 +186,7 @@ public final class PrivacyListManager extends Manager {
                 }
             }
         }, PRIVACY_RESULT);
-        connection.addConnectionListener(new AbstractConnectionListener() {
+        connection.addConnectionListener(new ConnectionListener() {
             @Override
             public void authenticated(XMPPConnection connection, boolean resumed) {
                 // No need to reset the cache if the connection got resumed.
diff --git a/smack-im/src/main/java/org/jivesoftware/smack/roster/Roster.java b/smack-im/src/main/java/org/jivesoftware/smack/roster/Roster.java
index 5bb91f283..dd05ac97b 100644
--- a/smack-im/src/main/java/org/jivesoftware/smack/roster/Roster.java
+++ b/smack-im/src/main/java/org/jivesoftware/smack/roster/Roster.java
@@ -33,9 +33,9 @@ import java.util.concurrent.CopyOnWriteArraySet;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
-import org.jivesoftware.smack.AbstractConnectionListener;
 import org.jivesoftware.smack.AsyncButOrdered;
 import org.jivesoftware.smack.ConnectionCreationListener;
+import org.jivesoftware.smack.ConnectionListener;
 import org.jivesoftware.smack.Manager;
 import org.jivesoftware.smack.SmackException;
 import org.jivesoftware.smack.SmackException.FeatureNotSupportedException;
@@ -313,7 +313,7 @@ public final class Roster extends Manager {
         }, PresenceTypeFilter.SUBSCRIBE);
 
         // Listen for connection events
-        connection.addConnectionListener(new AbstractConnectionListener() {
+        connection.addConnectionListener(new ConnectionListener() {
 
             @Override
             public void authenticated(XMPPConnection connection, boolean resumed) {
diff --git a/smack-omemo/src/main/java/org/jivesoftware/smackx/omemo/OmemoManager.java b/smack-omemo/src/main/java/org/jivesoftware/smackx/omemo/OmemoManager.java
index c319df84d..744bd6b89 100644
--- a/smack-omemo/src/main/java/org/jivesoftware/smackx/omemo/OmemoManager.java
+++ b/smack-omemo/src/main/java/org/jivesoftware/smackx/omemo/OmemoManager.java
@@ -34,7 +34,7 @@ import java.util.WeakHashMap;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
-import org.jivesoftware.smack.AbstractConnectionListener;
+import org.jivesoftware.smack.ConnectionListener;
 import org.jivesoftware.smack.Manager;
 import org.jivesoftware.smack.SmackException;
 import org.jivesoftware.smack.StanzaListener;
@@ -126,7 +126,7 @@ public final class OmemoManager extends Manager {
         if (connection.isAuthenticated()) {
             initBareJidAndDeviceId(this);
         } else {
-            connection.addConnectionListener(new AbstractConnectionListener() {
+            connection.addConnectionListener(new ConnectionListener() {
                 @Override
                 public void authenticated(XMPPConnection connection, boolean resumed) {
                     initBareJidAndDeviceId(OmemoManager.this);
diff --git a/smack-tcp/src/main/java/org/jivesoftware/smack/tcp/XMPPTCPConnection.java b/smack-tcp/src/main/java/org/jivesoftware/smack/tcp/XMPPTCPConnection.java
index 315f19830..f71e3f196 100644
--- a/smack-tcp/src/main/java/org/jivesoftware/smack/tcp/XMPPTCPConnection.java
+++ b/smack-tcp/src/main/java/org/jivesoftware/smack/tcp/XMPPTCPConnection.java
@@ -55,10 +55,10 @@ import javax.net.ssl.HostnameVerifier;
 import javax.net.ssl.SSLSession;
 import javax.net.ssl.SSLSocket;
 
-import org.jivesoftware.smack.AbstractConnectionListener;
 import org.jivesoftware.smack.AbstractXMPPConnection;
 import org.jivesoftware.smack.ConnectionConfiguration;
 import org.jivesoftware.smack.ConnectionConfiguration.SecurityMode;
+import org.jivesoftware.smack.ConnectionListener;
 import org.jivesoftware.smack.SmackConfiguration;
 import org.jivesoftware.smack.SmackException;
 import org.jivesoftware.smack.SmackException.AlreadyConnectedException;
@@ -294,7 +294,7 @@ public class XMPPTCPConnection extends AbstractXMPPConnection {
     public XMPPTCPConnection(XMPPTCPConnectionConfiguration config) {
         super(config);
         this.config = config;
-        addConnectionListener(new AbstractConnectionListener() {
+        addConnectionListener(new ConnectionListener() {
             @Override
             public void connectionClosedOnError(Exception e) {
                 if (e instanceof XMPPException.StreamErrorException || e instanceof StreamManagementException) {