AMQ-9162 Fix WS transport start via JMX after it was closed.

activemq-http/src/main/java/org/apache/activemq/transport/ws/WSTransportServer.java

@@ -96,7 +96,13 @@ protected void doStart() throws Exception {
 
         contextHandler.setAttribute("acceptListener", getAcceptListener());
 
-        server.start();
+        ClassLoader original = Thread.currentThread().getContextClassLoader();
+        Thread.currentThread().setContextClassLoader(WSTransportServer.class.getClassLoader());
+        try {
+            server.start();
+        } finally {
+            Thread.currentThread().setContextClassLoader(original);
+        }
 
         // Update the Connect To URI with our actual location in case the configured port
         // was set to zero so that we report the actual port we are listening on.

activemq-http/src/test/java/org/apache/activemq/transport/ws/WSConnectorJMXTest.java

@@ -0,0 +1,67 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.activemq.transport.ws;
+
+import org.apache.activemq.broker.BrokerService;
+import org.apache.activemq.broker.jmx.ConnectorViewMBean;
+import org.apache.activemq.util.Wait;
+import org.junit.Before;
+import org.junit.Test;
+
+import javax.management.ObjectName;
+import java.util.concurrent.TimeUnit;
+
+import static org.junit.Assert.assertTrue;
+
+public class WSConnectorJMXTest {
+
+    private BrokerService broker;
+
+    @Before
+    public void setUp() throws Exception {
+        broker = new BrokerService();
+        broker.setDeleteAllMessagesOnStartup(true);
+        broker.setPersistent(true);
+        broker.setUseJmx(true);
+        broker.addConnector("ws://localhost:0").setName("Default");
+        broker.setBrokerName("localhost");
+        broker.start();
+        broker.waitUntilStarted(30_000);
+        broker.deleteAllMessages();
+    }
+
+    @Test
+    public void testRestartConnection() throws Exception {
+        Thread.currentThread().setContextClassLoader(new ClassLoader(null) {});
+
+        ConnectorViewMBean connectionView = getProxyToConnectionView();
+        connectionView.stop();
+        assertTrue("Connection should close", Wait.waitFor(() -> !connectionView.isStarted(),
+                TimeUnit.SECONDS.toMillis(60), 500));
+        connectionView.start();
+        assertTrue("Connection should open", Wait.waitFor(connectionView::isStarted,
+                TimeUnit.SECONDS.toMillis(60), 500));
+    }
+
+    protected ConnectorViewMBean getProxyToConnectionView() throws Exception {
+        ObjectName connectorQuery = new ObjectName(
+                "org.apache.activemq:type=Broker,brokerName=localhost,connector=clientConnectors,connectorName=Default");
+
+        return (ConnectorViewMBean) broker.getManagementContext()
+                .newProxyInstance(connectorQuery, ConnectorViewMBean.class, true);
+    }
+}