Make the supported Transports extensible and discoverable

The new TransportProtocol type describes what a particular Transport
implementation wants in order to support a connection.  3rd parties
can now plug into the Transport.open() logic by implementing their
own TransportProtocol and Transport classes, and registering with
Transport.register().

GUI applications can help the user configure a connection by looking
at the supported fields of a particular TransportProtocol type, which
makes the GUI more dynamic and may better support new Transports.

Change-Id: Iafd8e3a6285261412aac6cba8e2c333f8b7b76a5
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

2 files changed, 27 insertions, 16 deletions

diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/api/FetchCommand.java b/org.eclipse.jgit/src/org/eclipse/jgit/api/FetchCommand.java
index 9594dfebe7..51dc5295fa 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/api/FetchCommand.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/api/FetchCommand.java
@@ -50,6 +50,7 @@ import java.util.List;
 import org.eclipse.jgit.JGitText;
 import org.eclipse.jgit.api.errors.InvalidRemoteException;
 import org.eclipse.jgit.api.errors.JGitInternalException;
+import org.eclipse.jgit.errors.NoRemoteRepositoryException;
 import org.eclipse.jgit.errors.NotSupportedException;
 import org.eclipse.jgit.errors.TransportException;
 import org.eclipse.jgit.lib.Constants;
@@ -121,27 +122,29 @@ public class FetchCommand extends GitCommand<FetchResult> {
 
 		try {
 			Transport transport = Transport.open(repo, remote);
-			transport.setCheckFetchedObjects(checkFetchedObjects);
-			transport.setRemoveDeletedRefs(removeDeletedRefs);
-			transport.setTimeout(timeout);
-			transport.setDryRun(dryRun);
-			if (tagOption != null)
-				transport.setTagOpt(tagOption);
-			transport.setFetchThin(thin);
-			if (credentialsProvider != null)
-				transport.setCredentialsProvider(credentialsProvider);
-
 			try {
+				transport.setCheckFetchedObjects(checkFetchedObjects);
+				transport.setRemoveDeletedRefs(removeDeletedRefs);
+				transport.setTimeout(timeout);
+				transport.setDryRun(dryRun);
+				if (tagOption != null)
+					transport.setTagOpt(tagOption);
+				transport.setFetchThin(thin);
+				if (credentialsProvider != null)
+					transport.setCredentialsProvider(credentialsProvider);
+
 				FetchResult result = transport.fetch(monitor, refSpecs);
 				return result;
-
-			} catch (TransportException e) {
-				throw new JGitInternalException(
-						JGitText.get().exceptionCaughtDuringExecutionOfFetchCommand,
-						e);
 			} finally {
 				transport.close();
 			}
+		} catch (NoRemoteRepositoryException e) {
+			throw new InvalidRemoteException(MessageFormat.format(
+					JGitText.get().invalidRemote, remote), e);
+		} catch (TransportException e) {
+			throw new JGitInternalException(
+					JGitText.get().exceptionCaughtDuringExecutionOfFetchCommand,
+					e);
 		} catch (URISyntaxException e) {
 			throw new InvalidRemoteException(MessageFormat.format(
 					JGitText.get().invalidRemote, remote));
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/api/errors/InvalidRemoteException.java b/org.eclipse.jgit/src/org/eclipse/jgit/api/errors/InvalidRemoteException.java
index 4104fd669b..3f059b79c7 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/api/errors/InvalidRemoteException.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/api/errors/InvalidRemoteException.java
@@ -44,9 +44,17 @@ public class InvalidRemoteException extends GitAPIException {
 	private static final long serialVersionUID = 1L;
 
 	/**
-	 * @param msg
+	 * @param msg message describing the invalid remote.
 	 */
 	public InvalidRemoteException(String msg) {
 		super(msg);
 	}
+
+	/**
+	 * @param msg message describing the invalid remote.
+	 * @param cause why the remote is invalid.
+	 */
+	public InvalidRemoteException(String msg, Throwable cause) {
+		super(msg, cause);
+	}
 }