/*

 * Copyright (c) 2004, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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package sun.jvmstat.perfdata.monitor.protocol.rmi;

import java.util.*;

import java.util.regex.*;

import java.io.*;

import java.rmi.RemoteException;

import sun.jvmstat.monitor.*;

import sun.jvmstat.monitor.event.*;

import sun.jvmstat.monitor.remote.*;

/**

 * Class for managing the RemoteMonitoredVm instances on a remote system.

 * <p>

 * This class is responsible for the mechanism that detects the active

 * HotSpot Java Virtual Machines on the remote host and possibly for a

 * specific user. The ability to detect all possible HotSpot Java Virtual

 * Machines on the remote host may be limited by the permissions of the

 * principal running the RMI server application on the remote host.

 *

 * @author Brian Doherty

 * @since 1.5

 */

public class RemoteVmManager {

    private RemoteHost remoteHost;

    private String user;

    /**

     * Creates a RemoteVmManager instance for the remote system.

     * <p>

     * Manages RemoteMonitordVm instances for which the principal

     * running the remote server has appropriate permissions.

     *

     * @param remoteHost the remote proxy object to the RMI server on

     *                   the remote system.

     */

    public RemoteVmManager(RemoteHost remoteHost) {

        this(remoteHost, null);

    }

    /**

     * Creates a RemoteVmManager instance for the given user.

     * <p>

     * Manages RemoteMonitoredVm instances for all remote Java Virtual

     * machines owned by the specified user on the remote system. The

     * RMI server on the remote system must have the appropriate permissions

     * to access the named users Java Virtual Machines.

     *

     * @param remoteHost the remote proxy object to the RMI server on

     *                   the remote system.

     * @param user the name of the user

     */

    public RemoteVmManager(RemoteHost remoteHost, String user) {

        this.user = user;

        this.remoteHost = remoteHost;

    }

    /**

     * Return the current set of monitorable Java Virtual Machines.

     * <p>

     * The set returned by this method depends on the user name passed

     * to the constructor. If no user name was specified, then this

     * method will return all candidate JVMs on the system. Otherwise,

     * only the JVMs for the given user will be returned. This assumes

     * that the RMI server process has the appropriate permissions to

     * access the target set of JVMs.

     *

     * @return Set - the Set of monitorable Java Virtual Machines

     */

    public Set<Integer> activeVms() throws MonitorException {

        int[] active = null;

        try {

            active = remoteHost.activeVms();

        } catch (RemoteException e) {

            throw new MonitorException("Error communicating with remote host: "

                                       + e.getMessage(), e);

        }

        Set<Integer> activeSet = new HashSet<Integer>(active.length);

        for (int i = 0; i < active.length; i++) {

            activeSet.add(new Integer(active[i]));

        }

        return activeSet;

    }

}