SFTP: Add channelConnectTimeout

While investigating an SI build failure, I noticed that there is
a timeout available for when connecting channels.

This won't resolve the build issue (where the session closed) but
worth adding as a property.

spring-integration-sftp/src/main/java/org/springframework/integration/sftp/session/DefaultSftpSessionFactory.java

@@ -17,6 +17,7 @@
 package org.springframework.integration.sftp.session;
 
 import java.io.IOException;
+import java.time.Duration;
 import java.util.Arrays;
 import java.util.Properties;
 import java.util.concurrent.locks.Lock;
@@ -108,6 +109,8 @@ public class DefaultSftpSessionFactory implements SessionFactory<LsEntry>, Share
 
 	private boolean allowUnknownKeys = false;
 
+	private Duration channelConnectTimeout;
+
 	private volatile JSchSessionWrapper sharedJschSession;
 
 
@@ -353,6 +356,16 @@ public class DefaultSftpSessionFactory implements SessionFactory<LsEntry>, Share
 		this.allowUnknownKeys = allowUnknownKeys;
 	}
 
+	/**
+	 * Set the connect timeout.
+	 * @param timeout the timeout to set.
+	 * @since 5.2
+	 */
+	public void setChannelConnectTimeout(Duration timeout) {
+		Assert.notNull(timeout, "'connectTimeout' cannot be null");
+		this.channelConnectTimeout = timeout;
+	}
+
 	@Override
 	public SftpSession getSession() {
 		JSchSessionWrapper jschSession = this.sharedJschSession;
@@ -367,6 +380,8 @@ public class DefaultSftpSessionFactory implements SessionFactory<LsEntry>, Share
 				freshJschSession = true;
 			}
 			sftpSession = new SftpSession(jschSession);
+			JavaUtils.INSTANCE
+				.acceptIfNotNull(this.channelConnectTimeout, sftpSession::setChannelConnectTimeout);
 			sftpSession.connect();
 			if (this.isSharedSession && freshJschSession) {
 				this.sharedJschSession = jschSession;

spring-integration-sftp/src/main/java/org/springframework/integration/sftp/session/SftpSession.java

@@ -19,6 +19,7 @@ package org.springframework.integration.sftp.session;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
+import java.time.Duration;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Vector;
@@ -51,12 +52,16 @@ public class SftpSession implements Session<LsEntry> {
 
 	private static final String SESSION_IS_NOT_CONNECTED = "session is not connected";
 
+	private static final Duration DEFAULT_CHANNEL_CONNECT_TIMEOUT = Duration.ofSeconds(5);
+
 	private final Log logger = LogFactory.getLog(this.getClass());
 
 	private final com.jcraft.jsch.Session jschSession;
 
 	private final JSchSessionWrapper wrapper;
 
+	private int channelConnectTimeout = (int) DEFAULT_CHANNEL_CONNECT_TIMEOUT.toMillis();
+
 	private volatile ChannelSftp channel;
 
 	private volatile boolean closed;
@@ -74,6 +79,16 @@ public class SftpSession implements Session<LsEntry> {
 		this.wrapper = wrapper;
 	}
 
+	/**
+	 * Set the connect timeout.
+	 * @param timeout the timeout to set.
+	 * @since 5.2
+	 */
+	public void setChannelConnectTimeout(Duration timeout) {
+		Assert.notNull(timeout, "'timeout' cannot be null");
+		this.channelConnectTimeout = (int) timeout.toMillis();
+	}
+
 	@Override
 	public boolean remove(String path) throws IOException {
 		Assert.state(this.channel != null, SESSION_IS_NOT_CONNECTED);
@@ -146,7 +161,7 @@ public class SftpSession implements Session<LsEntry> {
 	}
 
 	@Override
-	public boolean finalizeRaw() throws IOException {
+	public boolean finalizeRaw() {
 		return true;
 	}
 
@@ -258,7 +273,7 @@ public class SftpSession implements Session<LsEntry> {
 			this.channel.lstat(path);
 			return true;
 		}
-		catch (SftpException e) {
+		catch (@SuppressWarnings("unused") SftpException e) {
 			// ignore
 		}
 		return false;
@@ -271,7 +286,7 @@ public class SftpSession implements Session<LsEntry> {
 			}
 			this.channel = (ChannelSftp) this.jschSession.openChannel("sftp");
 			if (this.channel != null && !this.channel.isConnected()) {
-				this.channel.connect();
+				this.channel.connect(this.channelConnectTimeout);
 			}
 		}
 		catch (JSchException e) {
@@ -295,7 +310,7 @@ public class SftpSession implements Session<LsEntry> {
 			this.channel.lstat(this.channel.getHome());
 			return true;
 		}
-		catch (Exception e) {
+		catch (@SuppressWarnings("unused") Exception e) {
 			return false;
 		}
 	}

spring-integration-sftp/src/test/java/org/springframework/integration/sftp/outbound/SftpOutboundTests.java

@@ -20,6 +20,7 @@ import static org.assertj.core.api.Assertions.assertThat;
 import static org.mockito.ArgumentMatchers.anyString;
 import static org.mockito.BDDMockito.willAnswer;
 import static org.mockito.Mockito.doAnswer;
+import static org.mockito.Mockito.doNothing;
 import static org.mockito.Mockito.doReturn;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.never;
@@ -380,7 +381,7 @@ public class SftpOutboundTests {
 	}
 
 	private void noopConnect(ChannelSftp channel1) throws JSchException {
-		doAnswer(invocation -> null).when(channel1).connect();
+		doNothing().when(channel1).connect(5000);
 	}
 
 	public static class TestSftpSessionFactory extends DefaultSftpSessionFactory {

spring-integration-sftp/src/test/java/org/springframework/integration/sftp/session/SftpSessionFactoryTests.java

@@ -25,6 +25,7 @@ import static org.mockito.Mockito.when;
 import java.io.File;
 import java.io.IOException;
 import java.net.ConnectException;
+import java.time.Duration;
 import java.util.Collections;
 
 import org.apache.sshd.server.SshServer;
@@ -153,8 +154,11 @@ public class SftpSessionFactoryTests {
 		SshServer server = SshServer.setUpDefaultServer();
 		try {
 			DefaultSftpSessionFactory f = createServerAndClient(server);
+			f.setChannelConnectTimeout(Duration.ofSeconds(6));
 			f.setAllowUnknownKeys(true);
-			f.getSession().close();
+			SftpSession session = f.getSession();
+			assertThat(TestUtils.getPropertyValue(session, "channelConnectTimeout", Integer.class)).isEqualTo(6_000);
+			session.close();
 		}
 		finally {
 			server.stop(true);