1 files changed, 89 insertions, 0 deletions
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/util/Monitoring.java b/org.eclipse.jgit/src/org/eclipse/jgit/util/Monitoring.java
new file mode 100644
index 0000000000..500c236730
--- /dev/null
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/util/Monitoring.java
@@ -0,0 +1,89 @@
+/*
+ * Copyright (c) 2019 Matthias Sohn <matthias.sohn@sap.com>
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Distribution License v. 1.0 which is available at
+ * https://www.eclipse.org/org/documents/edl-v10.php.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+package org.eclipse.jgit.util;
+
+import java.io.IOException;
+import java.lang.management.ManagementFactory;
+
+import javax.management.InstanceAlreadyExistsException;
+import javax.management.InstanceNotFoundException;
+import javax.management.MBeanRegistrationException;
+import javax.management.MBeanServer;
+import javax.management.MalformedObjectNameException;
+import javax.management.NotCompliantMBeanException;
+import javax.management.ObjectInstance;
+import javax.management.ObjectName;
+
+import org.eclipse.jgit.annotations.Nullable;
+import org.eclipse.jgit.errors.ConfigInvalidException;
+import org.eclipse.jgit.lib.ConfigConstants;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Enables monitoring JGit via JMX
+ *
+ * @since 5.1.13
+ */
+public class Monitoring {
+	private static final Logger LOG = LoggerFactory.getLogger(Monitoring.class);
+
+	/**
+	 * Register a MBean with the platform MBean server
+	 *
+	 * @param mbean
+	 *            the mbean object to register
+	 * @param metricName
+	 *            name of the JGit metric, will be prefixed with
+	 *            "org.eclipse.jgit/"
+	 * @return the registered mbean's object instance
+	 */
+	public static @Nullable ObjectInstance registerMBean(Object mbean,
+			String metricName) {
+		boolean register = false;
+		try {
+			Class<?>[] interfaces = mbean.getClass().getInterfaces();
+			for (Class<?> i : interfaces) {
+				register = SystemReader.getInstance().getUserConfig()
+						.getBoolean(
+					ConfigConstants.CONFIG_JMX_SECTION,
+								i.getSimpleName(), false);
+				if (register) {
+					break;
+				}
+			}
+		} catch (IOException | ConfigInvalidException e) {
+			LOG.error(e.getMessage(), e);
+			return null;
+		}
+		if (!register) {
+			return null;
+		}
+		MBeanServer server = ManagementFactory.getPlatformMBeanServer();
+		try {
+			ObjectName mbeanName = objectName(mbean.getClass(), metricName);
+			if (server.isRegistered(mbeanName)) {
+				server.unregisterMBean(mbeanName);
+			}
+			return server.registerMBean(mbean, mbeanName);
+		} catch (MalformedObjectNameException | InstanceAlreadyExistsException
+				| MBeanRegistrationException | NotCompliantMBeanException
+				| InstanceNotFoundException e) {
+			LOG.error(e.getMessage(), e);
+			return null;
+		}
+	}
+
+	private static ObjectName objectName(Class mbean, String metricName)
+			throws MalformedObjectNameException {
+		return new ObjectName(String.format("org.eclipse.jgit/%s:type=%s", //$NON-NLS-1$
+				metricName, mbean.getSimpleName()));
+	}
+}