[SSHD-1330] Using common keep-alive global request handler in client as well as server

CHANGES.md

@@ -45,6 +45,7 @@
 
 ## New Features
 
+* [SSHD-1330](https://issues.apache.org/jira/browse/SSHD-1330) Use `KeepAliveHandler` global request instance in client as well
 * [GH-356](https://github.com/apache/mina-sshd/issues/356) Publish snapshot maven artifacts to the [Apache Snapshots](https://repository.apache.org/content/repositories/snapshots) maven repository.
 * Bundle _sshd-contrib_ has support classes for the [HAProxy protocol V2](https://www.haproxy.org/download/2.7/doc/proxy-protocol.txt).
 
@@ -69,6 +70,12 @@ actual data transfer, it also completely avoids the WS_FTP bug mentioned in
 
 ## Potential compatibility issues
 
+### `KeepAliveHandler` global request handler moved from server to common global requests package
+
+Was previously only on server-side - now also for client (see [SSHD-1330](https://issues.apache.org/jira/browse/SSHD-1330)).
+This should be fully backward compatible since most servers do not send this request. However, if users have somehow added this
+handler to the client side independently, the code should be re-examined and the independent handler removed or make it replace the global one.
+
 ### Server-side SFTP file handle encoding
 
 The aforementioned fix for the size of SFTP file handles has the potential to

sshd-core/src/main/java/org/apache/sshd/client/ClientBuilder.java

@@ -19,6 +19,7 @@
 
 package org.apache.sshd.client;
 
+import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
 import java.util.function.Function;
@@ -39,6 +40,7 @@
 import org.apache.sshd.common.compression.Compression;
 import org.apache.sshd.common.compression.CompressionFactory;
 import org.apache.sshd.common.config.keys.FilePasswordProvider;
+import org.apache.sshd.common.global.KeepAliveHandler;
 import org.apache.sshd.common.kex.DHFactory;
 import org.apache.sshd.common.kex.KeyExchange;
 import org.apache.sshd.common.kex.KeyExchangeFactory;
@@ -67,7 +69,9 @@ public class ClientBuilder extends BaseBuilder<SshClient, ClientBuilder> {
     public static final List<ChannelFactory> DEFAULT_CHANNEL_FACTORIES
             = Collections.unmodifiableList(Collections.singletonList(ForwardedTcpipFactory.INSTANCE));
     public static final List<RequestHandler<ConnectionService>> DEFAULT_GLOBAL_REQUEST_HANDLERS
-            = Collections.unmodifiableList(Collections.singletonList(OpenSshHostKeysHandler.INSTANCE));
+            = Collections.unmodifiableList(
+                    Arrays.<RequestHandler<ConnectionService>> asList(OpenSshHostKeysHandler.INSTANCE,
+                            KeepAliveHandler.INSTANCE));
 
     public static final ServerKeyVerifier DEFAULT_SERVER_KEY_VERIFIER = AcceptAllServerKeyVerifier.INSTANCE;
     public static final HostConfigEntryResolver DEFAULT_HOST_CONFIG_ENTRY_RESOLVER

sshd-core/src/main/java/org/apache/sshd/server/global/KeepAliveHandler.java → sshd-core/src/main/java/org/apache/sshd/common/global/KeepAliveHandler.java

@@ -16,7 +16,7 @@
  * specific language governing permissions and limitations
  * under the License.
  */
-package org.apache.sshd.server.global;
+package org.apache.sshd.common.global;
 
 import org.apache.sshd.common.SshConstants;
 import org.apache.sshd.common.session.ConnectionService;

sshd-core/src/main/java/org/apache/sshd/server/ServerBuilder.java

@@ -31,6 +31,7 @@
 import org.apache.sshd.common.compression.BuiltinCompressions;
 import org.apache.sshd.common.compression.Compression;
 import org.apache.sshd.common.compression.CompressionFactory;
+import org.apache.sshd.common.global.KeepAliveHandler;
 import org.apache.sshd.common.kex.DHFactory;
 import org.apache.sshd.common.kex.KeyExchange;
 import org.apache.sshd.common.kex.KeyExchangeFactory;
@@ -45,7 +46,6 @@
 import org.apache.sshd.server.config.keys.DefaultAuthorizedKeysAuthenticator;
 import org.apache.sshd.server.forward.DirectTcpipFactory;
 import org.apache.sshd.server.global.CancelTcpipForwardHandler;
-import org.apache.sshd.server.global.KeepAliveHandler;
 import org.apache.sshd.server.global.NoMoreSessionsHandler;
 import org.apache.sshd.server.global.OpenSshHostKeysHandler;
 import org.apache.sshd.server.global.TcpipForwardHandler;