log4j-jmx-gui/src/main/java/org/apache/logging/log4j/jmx/gui/ClientGui.java - logging-log4j2 - Git at Google

 /*
  * 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.logging.log4j.jmx.gui;

 import java.awt.BorderLayout;
 import java.awt.Color;
 import java.awt.Component;
 import java.awt.Font;
 import java.awt.event.ActionEvent;
 import java.io.IOException;
 import java.io.PrintWriter;
 import java.io.StringWriter;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.Objects;
 import java.util.Properties;

 import javax.management.InstanceNotFoundException;
 import javax.management.JMException;
 import javax.management.ListenerNotFoundException;
 import javax.management.MBeanServerDelegate;
 import javax.management.MBeanServerNotification;
 import javax.management.MalformedObjectNameException;
 import javax.management.Notification;
 import javax.management.NotificationFilterSupport;
 import javax.management.NotificationListener;
 import javax.management.ObjectName;
 import javax.management.remote.JMXConnector;
 import javax.management.remote.JMXConnectorFactory;
 import javax.management.remote.JMXServiceURL;
 import javax.swing.AbstractAction;
 import javax.swing.JFrame;
 import javax.swing.JOptionPane;
 import javax.swing.JPanel;
 import javax.swing.JScrollPane;
 import javax.swing.JTabbedPane;
 import javax.swing.JTextArea;
 import javax.swing.JToggleButton;
 import javax.swing.ScrollPaneConstants;
 import javax.swing.SwingUtilities;
 import javax.swing.UIManager;
 import javax.swing.UIManager.LookAndFeelInfo;
 import javax.swing.WindowConstants;

 import org.apache.logging.log4j.core.jmx.LoggerContextAdminMBean;
 import org.apache.logging.log4j.core.jmx.Server;
 import org.apache.logging.log4j.core.jmx.StatusLoggerAdminMBean;

 /**
  * Swing GUI that connects to a Java process via JMX and allows the user to view
  * and modify the Log4j 2 configuration, as well as monitor status logs.
  *
  * @see <a href=
  *      "http://docs.oracle.com/javase/6/docs/technotes/guides/management/jconsole.html"
  *      >http://docs.oracle.com/javase/6/docs/technotes/guides/management/
  *      jconsole.html</a >
  */
 public class ClientGui extends JPanel implements NotificationListener {
     private static final long serialVersionUID = -253621277232291174L;
     private static final int INITIAL_STRING_WRITER_SIZE = 1024;
     private final Client client;
     private final Map<ObjectName, Component> contextObjNameToTabbedPaneMap = new HashMap<>();
     private final Map<ObjectName, JTextArea> statusLogTextAreaMap = new HashMap<>();
     private JTabbedPane tabbedPaneContexts;

     public ClientGui(final Client client) throws IOException, JMException {
         this.client = Objects.requireNonNull(client, "client");
         createWidgets();
         populateWidgets();

         // register for Notifications if LoggerContext MBean was added/removed
         final ObjectName addRemoveNotifs = MBeanServerDelegate.DELEGATE_NAME;
         final NotificationFilterSupport filter = new NotificationFilterSupport();
         filter.enableType(Server.DOMAIN); // only interested in Log4J2 MBeans
         client.getConnection().addNotificationListener(addRemoveNotifs, this, null, null);
     }

     private void createWidgets() {
         tabbedPaneContexts = new JTabbedPane();
         this.setLayout(new BorderLayout());
         this.add(tabbedPaneContexts, BorderLayout.CENTER);
     }

     private void populateWidgets() throws IOException, JMException {
         for (final LoggerContextAdminMBean ctx : client.getLoggerContextAdmins()) {
             addWidgetForLoggerContext(ctx);
         }
     }

     private void addWidgetForLoggerContext(final LoggerContextAdminMBean ctx) throws MalformedObjectNameException,
             IOException, InstanceNotFoundException {
         final JTabbedPane contextTabs = new JTabbedPane();
         contextObjNameToTabbedPaneMap.put(ctx.getObjectName(), contextTabs);
         tabbedPaneContexts.addTab("LoggerContext: " + ctx.getName(), contextTabs);

         final String contextName = ctx.getName();
         final StatusLoggerAdminMBean status = client.getStatusLoggerAdmin(contextName);
         if (status != null) {
             final JTextArea text = createTextArea();
             final String[] messages = status.getStatusDataHistory();
             for (final String message : messages) {
                 text.append(message + '\n');
             }
             statusLogTextAreaMap.put(ctx.getObjectName(), text);
             registerListeners(status);
             final JScrollPane scroll = scroll(text);
             contextTabs.addTab("StatusLogger", scroll);
         }

         final ClientEditConfigPanel editor = new ClientEditConfigPanel(ctx);
         contextTabs.addTab("Configuration", editor);
     }

     private void removeWidgetForLoggerContext(final ObjectName loggerContextObjName) throws JMException, IOException {
         final Component tab = contextObjNameToTabbedPaneMap.get(loggerContextObjName);
         if (tab != null) {
             tabbedPaneContexts.remove(tab);
         }
         statusLogTextAreaMap.remove(loggerContextObjName);
         final ObjectName objName = client.getStatusLoggerObjectName(loggerContextObjName);
         try {
             // System.out.println("Remove listener for " + objName);
             client.getConnection().removeNotificationListener(objName, this);
         } catch (final ListenerNotFoundException ignored) {
         }
     }

     private JTextArea createTextArea() {
         final JTextArea result = new JTextArea();
         result.setEditable(false);
         result.setBackground(this.getBackground());
         result.setForeground(Color.black);
         result.setFont(new Font(Font.MONOSPACED, Font.PLAIN, result.getFont().getSize()));
         result.setWrapStyleWord(true);
         return result;
     }

     private JScrollPane scroll(final JTextArea text) {
         final JToggleButton toggleButton = new JToggleButton();
         toggleButton.setAction(new AbstractAction() {
             private static final long serialVersionUID = -4214143754637722322L;

             @Override
             public void actionPerformed(final ActionEvent e) {
                 final boolean wrap = toggleButton.isSelected();
                 text.setLineWrap(wrap);
             }
         });
         toggleButton.setToolTipText("Toggle line wrapping");
         final JScrollPane scrollStatusLog = new JScrollPane(text, //
                 ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS, //
                 ScrollPaneConstants.HORIZONTAL_SCROLLBAR_ALWAYS);
         scrollStatusLog.setCorner(ScrollPaneConstants.LOWER_RIGHT_CORNER, toggleButton);
         return scrollStatusLog;
     }

     private void registerListeners(final StatusLoggerAdminMBean status) throws InstanceNotFoundException,
             MalformedObjectNameException, IOException {
         final NotificationFilterSupport filter = new NotificationFilterSupport();
         filter.enableType(StatusLoggerAdminMBean.NOTIF_TYPE_MESSAGE);
         final ObjectName objName = status.getObjectName();
         // System.out.println("Add listener for " + objName);
         client.getConnection().addNotificationListener(objName, this, filter, status.getContextName());
     }

     @Override
     public void handleNotification(final Notification notif, final Object paramObject) {
         SwingUtilities.invokeLater(() -> { // LOG4J2-538
             handleNotificationInAwtEventThread(notif, paramObject);
         });
     }

     private void handleNotificationInAwtEventThread(final Notification notif, final Object paramObject) {
         if (StatusLoggerAdminMBean.NOTIF_TYPE_MESSAGE.equals(notif.getType())) {
             if (!(paramObject instanceof ObjectName)) {
                 handle("Invalid notification object type", new ClassCastException(paramObject.getClass().getName()));
                 return;
             }
             final ObjectName param = (ObjectName) paramObject;
             final JTextArea text = statusLogTextAreaMap.get(param);
             if (text != null) {
                 text.append(notif.getMessage() + '\n');
             }
             return;
         }
         if (notif instanceof MBeanServerNotification) {
             final MBeanServerNotification mbsn = (MBeanServerNotification) notif;
             final ObjectName mbeanName = mbsn.getMBeanName();
             if (MBeanServerNotification.REGISTRATION_NOTIFICATION.equals(notif.getType())) {
                 onMBeanRegistered(mbeanName);
             } else if (MBeanServerNotification.UNREGISTRATION_NOTIFICATION.equals(notif.getType())) {
                 onMBeanUnregistered(mbeanName);
             }
         }
     }

     /**
      * Called every time a Log4J2 MBean was registered in the MBean server.
      *
      * @param mbeanName ObjectName of the registered Log4J2 MBean
      */
     private void onMBeanRegistered(final ObjectName mbeanName) {
         if (client.isLoggerContext(mbeanName)) {
             try {
                 final LoggerContextAdminMBean ctx = client.getLoggerContextAdmin(mbeanName);
                 addWidgetForLoggerContext(ctx);
             } catch (final Exception ex) {
                 handle("Could not add tab for new MBean " + mbeanName, ex);
             }
         }
     }

     /**
      * Called every time a Log4J2 MBean was unregistered from the MBean server.
      *
      * @param mbeanName ObjectName of the unregistered Log4J2 MBean
      */
     private void onMBeanUnregistered(final ObjectName mbeanName) {
         if (client.isLoggerContext(mbeanName)) {
             try {
                 removeWidgetForLoggerContext(mbeanName);
             } catch (final Exception ex) {
                 handle("Could not remove tab for " + mbeanName, ex);
             }
         }
     }

     private void handle(final String msg, final Exception ex) {
         System.err.println(msg);
         ex.printStackTrace();

         final StringWriter sw = new StringWriter(INITIAL_STRING_WRITER_SIZE);
         ex.printStackTrace(new PrintWriter(sw));
         JOptionPane.showMessageDialog(this, sw.toString(), msg, JOptionPane.ERROR_MESSAGE);
     }

     /**
      * Connects to the specified location and shows this panel in a window.
      * <p>
      * Useful links:
      * http://www.componative.com/content/controller/developer/insights
      * /jconsole3/
      *
      * @param args must have at least one parameter, which specifies the
      *            location to connect to. Must be of the form {@code host:port}
      *            or {@code service:jmx:rmi:///jndi/rmi://<host>:<port>/jmxrmi}
      *            or
      *            {@code service:jmx:rmi://<host>:<port>/jndi/rmi://<host>:<port>/jmxrmi}
      * @throws Exception if anything goes wrong
      */
     public static void main(final String[] args) throws Exception {
         if (args.length < 1) {
             usage();
             return;
         }
         String serviceUrl = args[0];
         if (!serviceUrl.startsWith("service:jmx")) {
             serviceUrl = "service:jmx:rmi:///jndi/rmi://" + args[0] + "/jmxrmi";
         }
         final JMXServiceURL url = new JMXServiceURL(serviceUrl);
         final Properties props = System.getProperties();
         final Map<String, String> paramMap = new HashMap<>(props.size());
         for (final String key : props.stringPropertyNames()) {
             paramMap.put(key, props.getProperty(key));
         }
         final JMXConnector connector = JMXConnectorFactory.connect(url, paramMap);
         final Client client = new Client(connector);
         final String title = "Log4j JMX Client - " + url;

         SwingUtilities.invokeLater(() -> {
             installLookAndFeel();
             try {
                 final ClientGui gui = new ClientGui(client);
                 final JFrame frame = new JFrame(title);
                 frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
                 frame.getContentPane().add(gui, BorderLayout.CENTER);
                 frame.pack();
                 frame.setVisible(true);
             } catch (final Exception ex) {
                 // if console is visible, print error so that
                 // the stack trace remains visible after error dialog is
                 // closed
                 ex.printStackTrace();

                 // show error in dialog: there may not be a console window
                 // visible
                 final StringWriter sr = new StringWriter();
                 ex.printStackTrace(new PrintWriter(sr));
                 JOptionPane.showMessageDialog(null, sr.toString(), "Error", JOptionPane.ERROR_MESSAGE);
             }
         });
     }

     private static void usage() {
         final String me = ClientGui.class.getName();
         System.err.println("Usage: java " + me + " <host>:<port>");
         System.err.println("   or: java " + me + " service:jmx:rmi:///jndi/rmi://<host>:<port>/jmxrmi");
         final String longAdr = " service:jmx:rmi://<host>:<port>/jndi/rmi://<host>:<port>/jmxrmi";
         System.err.println("   or: java " + me + longAdr);
     }

     private static void installLookAndFeel() {
         try {
             for (final LookAndFeelInfo info : UIManager.getInstalledLookAndFeels()) {
                 if ("Nimbus".equals(info.getName())) {
                     UIManager.setLookAndFeel(info.getClassName());
                     return;
                 }
             }
         } catch (final Exception ex) {
             ex.printStackTrace();
         }
         try {
             UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
         } catch (final Exception e) {
             e.printStackTrace();
         }
     }
 }
	/*
	* 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.logging.log4j.jmx.gui;

	import java.awt.BorderLayout;
	import java.awt.Color;
	import java.awt.Component;
	import java.awt.Font;
	import java.awt.event.ActionEvent;
	import java.io.IOException;
	import java.io.PrintWriter;
	import java.io.StringWriter;
	import java.util.HashMap;
	import java.util.Map;
	import java.util.Objects;
	import java.util.Properties;

	import javax.management.InstanceNotFoundException;
	import javax.management.JMException;
	import javax.management.ListenerNotFoundException;
	import javax.management.MBeanServerDelegate;
	import javax.management.MBeanServerNotification;
	import javax.management.MalformedObjectNameException;
	import javax.management.Notification;
	import javax.management.NotificationFilterSupport;
	import javax.management.NotificationListener;
	import javax.management.ObjectName;
	import javax.management.remote.JMXConnector;
	import javax.management.remote.JMXConnectorFactory;
	import javax.management.remote.JMXServiceURL;
	import javax.swing.AbstractAction;
	import javax.swing.JFrame;
	import javax.swing.JOptionPane;
	import javax.swing.JPanel;
	import javax.swing.JScrollPane;
	import javax.swing.JTabbedPane;
	import javax.swing.JTextArea;
	import javax.swing.JToggleButton;
	import javax.swing.ScrollPaneConstants;
	import javax.swing.SwingUtilities;
	import javax.swing.UIManager;
	import javax.swing.UIManager.LookAndFeelInfo;
	import javax.swing.WindowConstants;

	import org.apache.logging.log4j.core.jmx.LoggerContextAdminMBean;
	import org.apache.logging.log4j.core.jmx.Server;
	import org.apache.logging.log4j.core.jmx.StatusLoggerAdminMBean;

	/**
	* Swing GUI that connects to a Java process via JMX and allows the user to view
	* and modify the Log4j 2 configuration, as well as monitor status logs.
	*
	* @see <a href=
	* "http://docs.oracle.com/javase/6/docs/technotes/guides/management/jconsole.html"
	* >http://docs.oracle.com/javase/6/docs/technotes/guides/management/
	* jconsole.html</a >
	*/
	public class ClientGui extends JPanel implements NotificationListener {
	private static final long serialVersionUID = -253621277232291174L;
	private static final int INITIAL_STRING_WRITER_SIZE = 1024;
	private final Client client;
	private final Map<ObjectName, Component> contextObjNameToTabbedPaneMap = new HashMap<>();
	private final Map<ObjectName, JTextArea> statusLogTextAreaMap = new HashMap<>();
	private JTabbedPane tabbedPaneContexts;

	public ClientGui(final Client client) throws IOException, JMException {
	this.client = Objects.requireNonNull(client, "client");
	createWidgets();
	populateWidgets();

	// register for Notifications if LoggerContext MBean was added/removed
	final ObjectName addRemoveNotifs = MBeanServerDelegate.DELEGATE_NAME;
	final NotificationFilterSupport filter = new NotificationFilterSupport();
	filter.enableType(Server.DOMAIN); // only interested in Log4J2 MBeans
	client.getConnection().addNotificationListener(addRemoveNotifs, this, null, null);
	}

	private void createWidgets() {
	tabbedPaneContexts = new JTabbedPane();
	this.setLayout(new BorderLayout());
	this.add(tabbedPaneContexts, BorderLayout.CENTER);
	}

	private void populateWidgets() throws IOException, JMException {
	for (final LoggerContextAdminMBean ctx : client.getLoggerContextAdmins()) {
	addWidgetForLoggerContext(ctx);
	}
	}

	private void addWidgetForLoggerContext(final LoggerContextAdminMBean ctx) throws MalformedObjectNameException,
	IOException, InstanceNotFoundException {
	final JTabbedPane contextTabs = new JTabbedPane();
	contextObjNameToTabbedPaneMap.put(ctx.getObjectName(), contextTabs);
	tabbedPaneContexts.addTab("LoggerContext: " + ctx.getName(), contextTabs);

	final String contextName = ctx.getName();
	final StatusLoggerAdminMBean status = client.getStatusLoggerAdmin(contextName);
	if (status != null) {
	final JTextArea text = createTextArea();
	final String[] messages = status.getStatusDataHistory();
	for (final String message : messages) {
	text.append(message + '\n');
	}
	statusLogTextAreaMap.put(ctx.getObjectName(), text);
	registerListeners(status);
	final JScrollPane scroll = scroll(text);
	contextTabs.addTab("StatusLogger", scroll);
	}

	final ClientEditConfigPanel editor = new ClientEditConfigPanel(ctx);
	contextTabs.addTab("Configuration", editor);
	}

	private void removeWidgetForLoggerContext(final ObjectName loggerContextObjName) throws JMException, IOException {
	final Component tab = contextObjNameToTabbedPaneMap.get(loggerContextObjName);
	if (tab != null) {
	tabbedPaneContexts.remove(tab);
	}
	statusLogTextAreaMap.remove(loggerContextObjName);
	final ObjectName objName = client.getStatusLoggerObjectName(loggerContextObjName);
	try {
	// System.out.println("Remove listener for " + objName);
	client.getConnection().removeNotificationListener(objName, this);
	} catch (final ListenerNotFoundException ignored) {
	}
	}

	private JTextArea createTextArea() {
	final JTextArea result = new JTextArea();
	result.setEditable(false);
	result.setBackground(this.getBackground());
	result.setForeground(Color.black);
	result.setFont(new Font(Font.MONOSPACED, Font.PLAIN, result.getFont().getSize()));
	result.setWrapStyleWord(true);
	return result;
	}

	private JScrollPane scroll(final JTextArea text) {
	final JToggleButton toggleButton = new JToggleButton();
	toggleButton.setAction(new AbstractAction() {
	private static final long serialVersionUID = -4214143754637722322L;

	@Override
	public void actionPerformed(final ActionEvent e) {
	final boolean wrap = toggleButton.isSelected();
	text.setLineWrap(wrap);
	}
	});
	toggleButton.setToolTipText("Toggle line wrapping");
	final JScrollPane scrollStatusLog = new JScrollPane(text, //
	ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS, //
	ScrollPaneConstants.HORIZONTAL_SCROLLBAR_ALWAYS);
	scrollStatusLog.setCorner(ScrollPaneConstants.LOWER_RIGHT_CORNER, toggleButton);
	return scrollStatusLog;
	}

	private void registerListeners(final StatusLoggerAdminMBean status) throws InstanceNotFoundException,
	MalformedObjectNameException, IOException {
	final NotificationFilterSupport filter = new NotificationFilterSupport();
	filter.enableType(StatusLoggerAdminMBean.NOTIF_TYPE_MESSAGE);
	final ObjectName objName = status.getObjectName();
	// System.out.println("Add listener for " + objName);
	client.getConnection().addNotificationListener(objName, this, filter, status.getContextName());
	}

	@Override
	public void handleNotification(final Notification notif, final Object paramObject) {
	SwingUtilities.invokeLater(() -> { // LOG4J2-538
	handleNotificationInAwtEventThread(notif, paramObject);
	});
	}

	private void handleNotificationInAwtEventThread(final Notification notif, final Object paramObject) {
	if (StatusLoggerAdminMBean.NOTIF_TYPE_MESSAGE.equals(notif.getType())) {
	if (!(paramObject instanceof ObjectName)) {
	handle("Invalid notification object type", new ClassCastException(paramObject.getClass().getName()));
	return;
	}
	final ObjectName param = (ObjectName) paramObject;
	final JTextArea text = statusLogTextAreaMap.get(param);
	if (text != null) {
	text.append(notif.getMessage() + '\n');
	}
	return;
	}
	if (notif instanceof MBeanServerNotification) {
	final MBeanServerNotification mbsn = (MBeanServerNotification) notif;
	final ObjectName mbeanName = mbsn.getMBeanName();
	if (MBeanServerNotification.REGISTRATION_NOTIFICATION.equals(notif.getType())) {
	onMBeanRegistered(mbeanName);
	} else if (MBeanServerNotification.UNREGISTRATION_NOTIFICATION.equals(notif.getType())) {
	onMBeanUnregistered(mbeanName);
	}
	}
	}

	/**
	* Called every time a Log4J2 MBean was registered in the MBean server.
	*
	* @param mbeanName ObjectName of the registered Log4J2 MBean
	*/
	private void onMBeanRegistered(final ObjectName mbeanName) {
	if (client.isLoggerContext(mbeanName)) {
	try {
	final LoggerContextAdminMBean ctx = client.getLoggerContextAdmin(mbeanName);
	addWidgetForLoggerContext(ctx);
	} catch (final Exception ex) {
	handle("Could not add tab for new MBean " + mbeanName, ex);
	}
	}
	}

	/**
	* Called every time a Log4J2 MBean was unregistered from the MBean server.
	*
	* @param mbeanName ObjectName of the unregistered Log4J2 MBean
	*/
	private void onMBeanUnregistered(final ObjectName mbeanName) {
	if (client.isLoggerContext(mbeanName)) {
	try {
	removeWidgetForLoggerContext(mbeanName);
	} catch (final Exception ex) {
	handle("Could not remove tab for " + mbeanName, ex);
	}
	}
	}

	private void handle(final String msg, final Exception ex) {
	System.err.println(msg);
	ex.printStackTrace();

	final StringWriter sw = new StringWriter(INITIAL_STRING_WRITER_SIZE);
	ex.printStackTrace(new PrintWriter(sw));
	JOptionPane.showMessageDialog(this, sw.toString(), msg, JOptionPane.ERROR_MESSAGE);
	}

	/**
	* Connects to the specified location and shows this panel in a window.
	* <p>
	* Useful links:
	* http://www.componative.com/content/controller/developer/insights
	* /jconsole3/
	*
	* @param args must have at least one parameter, which specifies the
	* location to connect to. Must be of the form {@code host:port}
	* or {@code service:jmx:rmi:///jndi/rmi://<host>:<port>/jmxrmi}
	* or
	* {@code service:jmx:rmi://<host>:<port>/jndi/rmi://<host>:<port>/jmxrmi}
	* @throws Exception if anything goes wrong
	*/
	public static void main(final String[] args) throws Exception {
	if (args.length < 1) {
	usage();
	return;
	}
	String serviceUrl = args[0];
	if (!serviceUrl.startsWith("service:jmx")) {
	serviceUrl = "service:jmx:rmi:///jndi/rmi://" + args[0] + "/jmxrmi";
	}
	final JMXServiceURL url = new JMXServiceURL(serviceUrl);
	final Properties props = System.getProperties();
	final Map<String, String> paramMap = new HashMap<>(props.size());
	for (final String key : props.stringPropertyNames()) {
	paramMap.put(key, props.getProperty(key));
	}
	final JMXConnector connector = JMXConnectorFactory.connect(url, paramMap);
	final Client client = new Client(connector);
	final String title = "Log4j JMX Client - " + url;

	SwingUtilities.invokeLater(() -> {
	installLookAndFeel();
	try {
	final ClientGui gui = new ClientGui(client);
	final JFrame frame = new JFrame(title);
	frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
	frame.getContentPane().add(gui, BorderLayout.CENTER);
	frame.pack();
	frame.setVisible(true);
	} catch (final Exception ex) {
	// if console is visible, print error so that
	// the stack trace remains visible after error dialog is
	// closed
	ex.printStackTrace();

	// show error in dialog: there may not be a console window
	// visible
	final StringWriter sr = new StringWriter();
	ex.printStackTrace(new PrintWriter(sr));
	JOptionPane.showMessageDialog(null, sr.toString(), "Error", JOptionPane.ERROR_MESSAGE);
	}
	});
	}

	private static void usage() {
	final String me = ClientGui.class.getName();
	System.err.println("Usage: java " + me + " <host>:<port>");
	System.err.println(" or: java " + me + " service:jmx:rmi:///jndi/rmi://<host>:<port>/jmxrmi");
	final String longAdr = " service:jmx:rmi://<host>:<port>/jndi/rmi://<host>:<port>/jmxrmi";
	System.err.println(" or: java " + me + longAdr);
	}

	private static void installLookAndFeel() {
	try {
	for (final LookAndFeelInfo info : UIManager.getInstalledLookAndFeels()) {
	if ("Nimbus".equals(info.getName())) {
	UIManager.setLookAndFeel(info.getClassName());
	return;
	}
	}
	} catch (final Exception ex) {
	ex.printStackTrace();
	}
	try {
	UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
	} catch (final Exception e) {
	e.printStackTrace();
	}
	}
	}