reduce reliance on implicit channel close; add close() method to SFTP classes; update examples

src/main/java/net/schmizz/sshj/connection/ConnectionImpl.java

@@ -30,6 +30,7 @@ import net.schmizz.sshj.connection.channel.forwarded.ForwardedChannelOpener;
 import net.schmizz.sshj.transport.Transport;
 import net.schmizz.sshj.transport.TransportException;
 
+import java.util.HashSet;
 import java.util.LinkedList;
 import java.util.Map;
 import java.util.Queue;
@@ -248,9 +249,9 @@ public class ConnectionImpl
     public void notifyDisconnect()
             throws SSHException {
         super.notifyDisconnect();
-        FutureUtils.alertAll(new ConnectionException("Disconnected."), globalReqFutures);
-        for (Channel chan : channels.values())
-            chan.finishOff();
+        final ConnectionException ex = new ConnectionException("Disconnected.");
+        FutureUtils.alertAll(ex, globalReqFutures);
+        ErrorNotifiable.Util.alertAll(ex, new HashSet<Channel>(channels.values()));
     }
 
 }

src/main/java/net/schmizz/sshj/connection/channel/AbstractChannel.java

@@ -302,8 +302,7 @@ public abstract class AbstractChannel
         rwin.expand(howMuch);
     }
 
-    @Override
-    public void finishOff() {
+    protected void finishOff() {
         conn.forget(this);
         close.set();
     }

src/main/java/net/schmizz/sshj/connection/channel/Channel.java

@@ -117,9 +117,6 @@ public interface Channel
     /** @return whether the channel is open. */
     boolean isOpen();
 
-    /** Called when this channel's end-of-life has been reached. Subclasses may override but must call super. */
-    void finishOff();
-
     /**
      * Sends an EOF message to the server for this channel; indicating that no more data will be sent by us. The {@code
      * OutputStream} for this channel will be closed and no longer usable.

src/main/java/net/schmizz/sshj/sftp/SFTPClient.java

@@ -20,6 +20,7 @@ import net.schmizz.sshj.xfer.FilePermission;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import java.io.Closeable;
 import java.io.IOException;
 import java.util.Deque;
 import java.util.EnumSet;
@@ -27,7 +28,8 @@ import java.util.LinkedList;
 import java.util.List;
 import java.util.Set;
 
-public class SFTPClient {
+public class SFTPClient
+        implements Closeable {
 
     /** Logger */
     protected final Logger log = LoggerFactory.getLogger(getClass());
@@ -238,4 +240,10 @@ public class SFTPClient {
         xfer.upload(source, dest);
     }
 
+    @Override
+    public void close()
+            throws IOException {
+        sftp.close();
+    }
+
 }

src/main/java/net/schmizz/sshj/sftp/SFTPEngine.java

@@ -21,6 +21,7 @@ import net.schmizz.sshj.connection.channel.direct.SessionFactory;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import java.io.Closeable;
 import java.io.IOException;
 import java.io.OutputStream;
 import java.util.EnumSet;
@@ -30,7 +31,7 @@ import java.util.Set;
 import java.util.concurrent.TimeUnit;
 
 public class SFTPEngine
-        implements Requester {
+        implements Requester, Closeable {
 
     /** Logger */
     private final Logger log = LoggerFactory.getLogger(getClass());
@@ -233,4 +234,10 @@ public class SFTPEngine
         return timeout;
     }
 
+    @Override
+    public void close()
+            throws IOException {
+        sub.close();
+    }
+
 }

src/main/java/net/schmizz/sshj/transport/TransportImpl.java

@@ -421,8 +421,8 @@ public final class TransportImpl
                     .putInt(reason.toInt())
                     .putString(message)
                     .putString(""));
-        } catch (IOException logged) {
-            log.warn("Error writing packet: {}", logged);
+        } catch (IOException worthless) {
+            log.debug("Error writing packet: {}", worthless.toString());
         }
     }