/*

 * Copyright (c) 2004, 2005, 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

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package sun.jvmstat.monitor;

/**

 * Utility class proving concenience methods for extracting various

 * information from an MonitoredVm object.

 *

 * @author Brian Doherty

 * @since 1.5

 */

public class MonitoredVmUtil {

    /**

     * Private constructor - prevent instantiation.

     */

    private MonitoredVmUtil() { }

    /**

     * Return the Java Virtual Machine Version.

     *

     * @param vm the target MonitoredVm

     * @return String - contains the version of the target JVM or the

     *                  the string "Unknown" if the version cannot be

     *                  determined.

     */

    public static String vmVersion(MonitoredVm vm) throws MonitorException {

        StringMonitor ver =

               (StringMonitor)vm.findByName("java.property.java.vm.version");

        return (ver == null) ? "Unknown" : ver.stringValue();

    }

    /**

     * Return the command line for the target Java application.

     *

     * @param vm the target MonitoredVm

     * @return String - contains the command line of the target Java

     *                  application or the the string "Unknown" if the

     *                  command line cannot be determined.

     */

    public static String commandLine(MonitoredVm vm) throws MonitorException {

        StringMonitor cmd = (StringMonitor)vm.findByName("sun.rt.javaCommand");

        return (cmd == null) ? "Unknown" : cmd.stringValue();

    }

    /**

     * Return the arguments to the main class for the target Java application.

     * Returns the arguments to the main class. If the arguments can't be

     * found, the string "Unknown" is returned.

     *

     * @param vm the target MonitoredVm

     * @return String - contains the arguments to the main class for the

     *                  target Java application or the the string "Unknown"

     *                  if the command line cannot be determined.

     */

    public static String mainArgs(MonitoredVm vm) throws MonitorException {

        String commandLine = commandLine(vm);

        int firstSpace = commandLine.indexOf(' ');

        if (firstSpace > 0) {

            return commandLine.substring(firstSpace + 1);

        } else if (commandLine.compareTo("Unknown") == 0) {

            return commandLine;

        } else {

            return null;

        }

    }

    /**

     * Return the main class for the target Java application.

     * Returns the main class or the name of the jar file if the application

     * was started with the <em>-jar</em> option.

     *

     * @param vm the target MonitoredVm

     * @param fullPath include the full path to Jar file, where applicable

     * @return String - contains the main class of the target Java

     *                  application or the the string "Unknown" if the

     *                  command line cannot be determined.

     */

    public static String mainClass(MonitoredVm vm, boolean fullPath)

                         throws MonitorException {

        String commandLine = commandLine(vm);

        String arg0 = commandLine;

        int firstSpace = commandLine.indexOf(' ');

        if (firstSpace > 0) {

            arg0 = commandLine.substring(0, firstSpace);

        }

        if (!fullPath) {

            /*

             * can't use File.separator() here because the separator

             * for the target jvm may be different than the separator

             * for the monitoring jvm.

             */

            int lastFileSeparator = arg0.lastIndexOf('/');

            if (lastFileSeparator > 0) {

                 return arg0.substring(lastFileSeparator + 1);

            }

            lastFileSeparator = arg0.lastIndexOf('\\');

            if (lastFileSeparator > 0) {

                 return arg0.substring(lastFileSeparator + 1);

            }

            int lastPackageSeparator = arg0.lastIndexOf('.');

            if (lastPackageSeparator > 0) {

                 return arg0.substring(lastPackageSeparator + 1);

            }

        }

        return arg0;

    }

    /**

     * Return the JVM arguments for the target Java application.

     *

     * @param vm the target MonitoredVm

     * @return String - contains the arguments passed to the JVM for the

     *                  target Java application or the the string "Unknown"

     *                  if the command line cannot be determined.

     */

    public static String jvmArgs(MonitoredVm vm) throws MonitorException {

        StringMonitor jvmArgs = (StringMonitor)vm.findByName("java.rt.vmArgs");

        return (jvmArgs == null) ? "Unknown" : jvmArgs.stringValue();

    }

    /**

     * Return the JVM flags for the target Java application.

     *

     * @param vm the target MonitoredVm

     * @return String - contains the flags passed to the JVM for the

     *                  target Java application or the the string "Unknown"

     *                  if the command line cannot be determined.

     */

    public static String jvmFlags(MonitoredVm vm) throws MonitorException {

        StringMonitor jvmFlags =

               (StringMonitor)vm.findByName("java.rt.vmFlags");

        return (jvmFlags == null) ? "Unknown" : jvmFlags.stringValue();

    }

    // Index of the sun.rt.jvmCapabilities counter

    private static int IS_ATTACHABLE = 0;

    private static int IS_KERNEL_VM  = 1;

    /**

     * Returns true if the VM supports attach-on-demand.

     *

     * @param vm the target MonitoredVm

     */

    public static boolean isAttachable(MonitoredVm vm) throws MonitorException {

        StringMonitor jvmCapabilities =

               (StringMonitor)vm.findByName("sun.rt.jvmCapabilities");

        if (jvmCapabilities == null) {

             return false;

        } else {

             return jvmCapabilities.stringValue().charAt(IS_ATTACHABLE) == '1';

        }

    }

}