Terminal Connector creation: throw instead of returning null

Returning `null` from the `create` method is very confusing. If terminal
connector cannot be created the `CoreException` should be thrown

Author: ruspl-afed

terminal/bundles/org.eclipse.terminal.connector.local/src/org/eclipse/terminal/connector/local/launcher/LocalLauncherDelegate.java

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2012, 2018 Wind River Systems, Inc. and others. All rights reserved.
+ * Copyright (c) 2012, 2025 Wind River Systems, Inc. and others. All rights reserved.
  * This program and the accompanying materials are made available under the terms
  * of the Eclipse Public License 2.0 which accompanies this distribution, and is
  * available at https://www.eclipse.org/legal/epl-2.0/
@@ -9,6 +9,7 @@
  * Contributors:
  * Wind River Systems - initial API and implementation
  * Dirk Fauth <[email protected]> - Bug 460496
+ * Alexander Fedorov (ArSysOp) - further evolution
  *******************************************************************************/
 package org.eclipse.terminal.connector.local.launcher;
 
@@ -292,7 +293,7 @@ private final File defaultShell() {
 	}
 
 	@Override
-	public ITerminalConnector createTerminalConnector(Map<String, Object> properties) {
+	public ITerminalConnector createTerminalConnector(Map<String, Object> properties) throws CoreException {
 		Assert.isNotNull(properties);
 
 		// Check for the terminal connector id
@@ -419,13 +420,10 @@ public ITerminalConnector createTerminalConnector(Map<String, Object> properties
 
 		// Construct the terminal connector instance
 		ITerminalConnector connector = TerminalConnectorExtension.makeTerminalConnector(connectorId);
-		if (connector != null) {
-			// Apply default settings
-			connector.setDefaultSettings();
-			// And load the real settings
-			connector.load(store);
-		}
-
+		// Apply default settings
+		connector.setDefaultSettings();
+		// And load the real settings
+		connector.load(store);
 		return connector;
 	}
 }

terminal/bundles/org.eclipse.terminal.connector.process/src/org/eclipse/terminal/connector/process/internal/ProcessLauncherDelegate.java

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2015, 2018 Wind River Systems, Inc. and others. All rights reserved.
+ * Copyright (c) 2015, 2025 Wind River Systems, Inc. and others. All rights reserved.
  * This program and the accompanying materials are made available under the terms
  * of the Eclipse Public License 2.0 which accompanies this distribution, and is
  * available at https://www.eclipse.org/legal/epl-2.0/
@@ -8,13 +8,15 @@
  *
  * Contributors:
  * Wind River Systems - initial API and implementation
+ * Alexander Fedorov (ArSysOp) - further evolution
  *******************************************************************************/
 package org.eclipse.terminal.connector.process.internal;
 
 import java.util.Map;
 
 import org.eclipse.cdt.utils.pty.PTY;
 import org.eclipse.core.runtime.Assert;
+import org.eclipse.core.runtime.CoreException;
 import org.eclipse.terminal.connector.ISettingsStore;
 import org.eclipse.terminal.connector.ITerminalConnector;
 import org.eclipse.terminal.connector.InMemorySettingsStore;
@@ -55,7 +57,7 @@ public void execute(Map<String, Object> properties, ITerminalService.Done done)
 	}
 
 	@Override
-	public ITerminalConnector createTerminalConnector(Map<String, Object> properties) {
+	public ITerminalConnector createTerminalConnector(Map<String, Object> properties) throws CoreException {
 		Assert.isNotNull(properties);
 
 		// Check for the terminal connector id
@@ -113,13 +115,10 @@ public ITerminalConnector createTerminalConnector(Map<String, Object> properties
 
 		// Construct the terminal connector instance
 		ITerminalConnector connector = TerminalConnectorExtension.makeTerminalConnector(connectorId);
-		if (connector != null) {
-			// Apply default settings
-			connector.setDefaultSettings();
-			// And load the real settings
-			connector.load(store);
-		}
-
+		// Apply default settings
+		connector.setDefaultSettings();
+		// And load the real settings
+		connector.load(store);
 		return connector;
 	}
 

terminal/bundles/org.eclipse.terminal.connector.ssh/src/org/eclipse/terminal/connector/ssh/launcher/SshLauncherDelegate.java

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2011, 2018 Wind River Systems, Inc. and others. All rights reserved.
+ * Copyright (c) 2011, 2025 Wind River Systems, Inc. and others. All rights reserved.
  * This program and the accompanying materials are made available under the terms
  * of the Eclipse Public License 2.0 which accompanies this distribution, and is
  * available at https://www.eclipse.org/legal/epl-2.0/
@@ -9,6 +9,7 @@
  * Contributors:
  * Wind River Systems - initial API and implementation
  * Max Weninger (Wind River) - [361352] [TERMINALS][SSH] Add SSH terminal support
+ * Alexander Fedorov (ArSysOp) - further evolution
  *******************************************************************************/
 package org.eclipse.terminal.connector.ssh.launcher;
 
@@ -17,6 +18,7 @@
 import java.util.Map;
 
 import org.eclipse.core.runtime.Assert;
+import org.eclipse.core.runtime.CoreException;
 import org.eclipse.osgi.util.NLS;
 import org.eclipse.terminal.connector.ISettingsStore;
 import org.eclipse.terminal.connector.ITerminalConnector;
@@ -118,7 +120,7 @@ public <T> T getAdapter(Class<T> adapter) {
 	}
 
 	@Override
-	public ITerminalConnector createTerminalConnector(Map<String, Object> properties) {
+	public ITerminalConnector createTerminalConnector(Map<String, Object> properties) throws CoreException {
 		Assert.isNotNull(properties);
 
 		// Check for the terminal connector id
@@ -171,13 +173,10 @@ public ITerminalConnector createTerminalConnector(Map<String, Object> properties
 
 		// Construct the terminal connector instance
 		ITerminalConnector connector = TerminalConnectorExtension.makeTerminalConnector(connectorId);
-		if (connector != null) {
-			// Apply default settings
-			connector.setDefaultSettings();
-			// And load the real settings
-			connector.load(store);
-		}
-
+		// Apply default settings
+		connector.setDefaultSettings();
+		// And load the real settings
+		connector.load(store);
 		return connector;
 	}
 }

terminal/bundles/org.eclipse.terminal.connector.telnet/src/org/eclipse/terminal/connector/telnet/launcher/TelnetLauncherDelegate.java

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2011, 2018 Wind River Systems, Inc. and others. All rights reserved.
+ * Copyright (c) 2011, 2025 Wind River Systems, Inc. and others. All rights reserved.
  * This program and the accompanying materials are made available under the terms
  * of the Eclipse Public License 2.0 which accompanies this distribution, and is
  * available at https://www.eclipse.org/legal/epl-2.0/
@@ -9,6 +9,7 @@
  * Contributors:
  * Wind River Systems - initial API and implementation
  * Max Weninger (Wind River) - [366374] [TERMINALS][TELNET] Add Telnet terminal support
+ * Alexander Fedorov (ArSysOp) - further evolution
  *******************************************************************************/
 package org.eclipse.terminal.connector.telnet.launcher;
 
@@ -17,6 +18,7 @@
 import java.util.Map;
 
 import org.eclipse.core.runtime.Assert;
+import org.eclipse.core.runtime.CoreException;
 import org.eclipse.osgi.util.NLS;
 import org.eclipse.terminal.connector.ISettingsStore;
 import org.eclipse.terminal.connector.ITerminalConnector;
@@ -108,7 +110,7 @@ public <T> T getAdapter(Class<T> adapter) {
 	}
 
 	@Override
-	public ITerminalConnector createTerminalConnector(Map<String, Object> properties) {
+	public ITerminalConnector createTerminalConnector(Map<String, Object> properties) throws CoreException {
 		Assert.isNotNull(properties);
 
 		// Check for the terminal connector id
@@ -154,13 +156,10 @@ public ITerminalConnector createTerminalConnector(Map<String, Object> properties
 
 		// Construct the terminal connector instance
 		ITerminalConnector connector = TerminalConnectorExtension.makeTerminalConnector(connectorId);
-		if (connector != null) {
-			// Apply default settings
-			connector.setDefaultSettings();
-			// And load the real settings
-			connector.load(store);
-		}
-
+		// Apply default settings
+		connector.setDefaultSettings();
+		// And load the real settings
+		connector.load(store);
 		return connector;
 	}
 }

terminal/bundles/org.eclipse.terminal.control/src/org/eclipse/terminal/connector/TerminalConnectorExtension.java

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2006, 2018 Wind River Systems, Inc. and others.
+ * Copyright (c) 2006, 2025 Wind River Systems, Inc. and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License 2.0
  * which accompanies this distribution, and is available at
@@ -11,16 +11,21 @@
  * Michael Scharf (Wind River) - initial API and implementation
  * Martin Oberhuber (Wind River) - fixed copyright headers and beautified
  * Uwe Stieber (Wind River) - [282996] [terminal][api] Add "hidden" attribute to terminal connector extension point
+ * Alexander Fedorov (ArSysOp) - further evolution
  *******************************************************************************/
 package org.eclipse.terminal.connector;
 
 import java.util.ArrayList;
 import java.util.List;
 
+import org.eclipse.core.runtime.CoreException;
 import org.eclipse.core.runtime.IConfigurationElement;
 import org.eclipse.core.runtime.RegistryFactory;
+import org.eclipse.core.runtime.Status;
+import org.eclipse.osgi.util.NLS;
 import org.eclipse.terminal.connector.provider.AbstractTerminalConnector;
 import org.eclipse.terminal.internal.connector.TerminalConnector;
+import org.eclipse.terminal.internal.control.impl.TerminalMessages;
 
 /**
  * A factory to get {@link ITerminalConnector} instances.
@@ -51,18 +56,19 @@ static private ITerminalConnector makeConnector(final IConfigurationElement conf
 	 * @param id the id of the terminal connector in the
 	 *            <code>org.eclipse.terminal.control.connectors</code>
 	 *            extension point
-	 * @return a new ITerminalConnector with id or <code>null</code> if there
-	 *         is no extension with that id.
+	 * @return a new ITerminalConnector for the given id.
+	 * @throws CoreException if connector cannot be created for provided input
 	 */
-	public static ITerminalConnector makeTerminalConnector(String id) {
+	public static ITerminalConnector makeTerminalConnector(String id) throws CoreException {
 		IConfigurationElement[] config = RegistryFactory.getRegistry()
 				.getConfigurationElementsFor("org.eclipse.terminal.control.connectors"); //$NON-NLS-1$
 		for (int i = 0; i < config.length; i++) {
 			if (id.equals(config[i].getAttribute("id"))) { //$NON-NLS-1$
 				return makeConnector(config[i]);
 			}
 		}
-		return null;
+		throw new CoreException(
+				Status.error(NLS.bind(TerminalMessages.TerminalConnectorExtension_e_no_connector_for_id, id)));
 	}
 
 	/**

terminal/bundles/org.eclipse.terminal.control/src/org/eclipse/terminal/internal/control/impl/TerminalMessages.java

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2006, 2018 Wind River Systems, Inc. and others.
+ * Copyright (c) 2006, 2025 Wind River Systems, Inc. and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License 2.0
  * which accompanies this distribution, and is available at
@@ -9,6 +9,7 @@
  * Michael Scharf (Wind River) - initial API and implementation
  * Martin Oberhuber (Wind River) - fixed copyright headers and beautified
  * Martin Oberhuber (Wind River) - [378691][api] push Preferences into the Widget
+ * Alexander Fedorov (ArSysOp) - further evolution
  *******************************************************************************/
 package org.eclipse.terminal.internal.control.impl;
 
@@ -46,6 +47,7 @@ public class TerminalMessages extends NLS {
 	public static String TerminalColorsFieldEditor_TextColor;
 	public static String TerminalColorsFieldEditor_White;
 	public static String TerminalColorsFieldEditor_Yellow;
+	public static String TerminalConnectorExtension_e_no_connector_for_id;
 	public static String TerminalError;
 	public static String SocketError;
 	public static String IOError;

terminal/bundles/org.eclipse.terminal.control/src/org/eclipse/terminal/internal/control/impl/TerminalMessages.properties

@@ -1,5 +1,5 @@
 ###############################################################################
-# Copyright (c) 2003, 2020 Wind River Systems, Inc. and others.
+# Copyright (c) 2003, 2025 Wind River Systems, Inc. and others.
 # All rights reserved. This program and the accompanying materials
 # are made available under the terms of the Eclipse Public License 2.0
 # which accompanies this distribution, and is available at
@@ -16,6 +16,7 @@
 # Michael Scharf (Wind River) - split into core, view and connector plugins
 # Martin Oberhuber (Wind River) - fixed copyright headers and beautified
 # Martin Oberhuber (Wind River) - [378691][api] push Preferences into the Widget
+# Alexander Fedorov (ArSysOp) - further evolution
 ###############################################################################
 
 # NLS_MESSAGEFORMAT_VAR
@@ -46,6 +47,7 @@ TerminalColorsFieldEditor_Selection=Selection
 TerminalColorsFieldEditor_TextColor=Text color
 TerminalColorsFieldEditor_White=White
 TerminalColorsFieldEditor_Yellow=Yellow
+TerminalConnectorExtension_e_no_connector_for_id=No terminal connector registered for id {0}
 TerminalError = Terminal Error
 SocketError = Socket Error
 IOError = IO Error

terminal/bundles/org.eclipse.terminal.view.ui/src/org/eclipse/terminal/view/ui/internal/TerminalService.java

@@ -31,6 +31,7 @@
 import org.eclipse.terminal.view.core.ITerminalsConnectorConstants;
 import org.eclipse.terminal.view.ui.IUIConstants;
 import org.eclipse.terminal.view.ui.TerminalViewId;
+import org.eclipse.terminal.view.ui.launcher.ILauncherDelegate;
 import org.eclipse.terminal.view.ui.launcher.ILauncherDelegateManager;
 import org.eclipse.terminal.view.ui.launcher.ITerminalConsoleViewManager;
 import org.eclipse.ui.PlatformUI;
@@ -180,29 +181,28 @@ protected final void executeServiceOperation(final Map<String, Object> propertie
 		title = normalizeTitle(title, data);
 
 		// Create the terminal connector instance
-		final ITerminalConnector connector = createTerminalConnector(properties);
-		if (connector == null) {
+		ITerminalConnector connector;
+		try {
+			connector = createTerminalConnector(properties);
+		} catch (CoreException e) {
 			// Properties contain invalid connector arguments
 			if (done != null) {
-				done.done(Status.error(Messages.TerminalService_error_cannotCreateConnector));
+				done.done(e.getStatus());
 			}
 			return;
 		}
+		executeServiceOperation(runnable, new TerminalViewId(id, secondaryId), title, connector, data, done);
+	}
 
-		// Finalize the used variables
-		final String finId = id;
-		final String finSecondaryId = secondaryId;
-		final String finTitle = title;
-		final Object finData = data;
-		TerminalViewId tvid = new TerminalViewId(finId, finSecondaryId);
-
+	private void executeServiceOperation(final TerminalServiceRunnable runnable, TerminalViewId tvid,
+			final String title, final ITerminalConnector connector, final Object data, final Done done) {
 		// Execute the operation
 		if (!runnable.isExecuteAsync()) {
-			runnable.run(tvid, finTitle, connector, finData, done);
+			runnable.run(tvid, title, connector, data, done);
 		} else {
 			try {
 				Display display = PlatformUI.getWorkbench().getDisplay();
-				display.asyncExec(() -> runnable.run(tvid, finTitle, connector, finData, done));
+				display.asyncExec(() -> runnable.run(tvid, title, connector, data, done));
 			} catch (Exception e) {
 				// if display is disposed, silently ignore.
 			}
@@ -243,14 +243,18 @@ protected String normalizeTitle(String title, Object data) {
 	 * Creates the terminal connector configured within the given properties.
 	 *
 	 * @param properties The terminal console properties. Must not be <code>null</code>.
-	 * @return The terminal connector or <code>null</code>.
+	 * @return The created terminal connector
+	 * @throws CoreException if connector cannot be created for provided input
 	 */
-	protected ITerminalConnector createTerminalConnector(Map<String, Object> properties) {
+	protected ITerminalConnector createTerminalConnector(Map<String, Object> properties) throws CoreException {
 		Assert.isNotNull(properties);
-		return Optional.of(properties).map(map -> map.get(ITerminalsConnectorConstants.PROP_DELEGATE_ID))
-				.filter(String.class::isInstance).map(String.class::cast)
-				.flatMap(id -> launchDelegateManager.findLauncherDelegate(id, false))
-				.map(d -> d.createTerminalConnector(properties)).orElse(null);
+		ILauncherDelegate delegate = Optional.of(properties)
+				.map(map -> map.get(ITerminalsConnectorConstants.PROP_DELEGATE_ID)).filter(String.class::isInstance)
+				.map(String.class::cast).flatMap(id -> launchDelegateManager.findLauncherDelegate(id, false))
+				.orElseThrow(
+						() -> new CoreException(Status.error(Messages.TerminalService_error_cannotCreateConnector)));
+
+		return delegate.createTerminalConnector(properties);
 	}
 
 	@Override