1   /***
2    * Redistribution and use of this software and associated documentation
3    * ("Software"), with or without modification, are permitted provided
4    * that the following conditions are met:
5    *
6    * 1. Redistributions of source code must retain copyright
7    *    statements and notices.  Redistributions must also contain a
8    *    copy of this document.
9    *
10   * 2. Redistributions in binary form must reproduce the
11   *    above copyright notice, this list of conditions and the
12   *    following disclaimer in the documentation and/or other
13   *    materials provided with the distribution.
14   *
15   * 3. The name "Exolab" must not be used to endorse or promote
16   *    products derived from this Software without prior written
17   *    permission of Exoffice Technologies.  For written permission,
18   *    please contact info@exolab.org.
19   *
20   * 4. Products derived from this Software may not be called "Exolab"
21   *    nor may "Exolab" appear in their names without prior written
22   *    permission of Exoffice Technologies. Exolab is a registered
23   *    trademark of Exoffice Technologies.
24   *
25   * 5. Due credit should be given to the Exolab Project
26   *    (http://www.exolab.org/).
27   *
28   * THIS SOFTWARE IS PROVIDED BY EXOFFICE TECHNOLOGIES AND CONTRIBUTORS
29   * ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT
30   * NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
31   * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
32   * EXOFFICE TECHNOLOGIES OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
33   * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
34   * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
35   * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
36   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
37   * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
38   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
39   * OF THE POSSIBILITY OF SUCH DAMAGE.
40   *
41   * Copyright 2004 (C) Exoffice Technologies Inc. All Rights Reserved.
42   *
43   * $Id: JVM.java,v 1.1 2004/11/26 01:51:10 tanderson Exp $
44   */
45  package org.exolab.jms.net.jvm;
46  
47  import java.util.Enumeration;
48  import java.util.Properties;
49  
50  
51  /***
52   * Helper for starting a new JVM.
53   *
54   * @version     $Revision: 1.1 $ $Date: 2004/11/26 01:51:10 $
55   * @author      <a href="mailto:tma@netspace.net.au">Tim Anderson</a>
56   */
57  public class JVM extends Executor {
58  
59      /***
60       * Construct a new <code>JVM</code>, specifying the classpath
61       * Output will be directed to System.out and System.err
62       *
63       * @param mainClass the fully qualified name of the main class
64       * @param classpath the classpath. If <code>null</code>, uses the
65       * value of the <code>"java.class.path"</code> system property
66       * @param sysProps system properties to pass to the JVM.
67       * May be <code>null</code>
68       * @param args the command line arguments. May be <code>null</code>
69       */
70      public JVM(String mainClass, String classpath, Properties sysProps,
71                 String args) {
72          super(getCommand(mainClass, classpath, sysProps, args));
73      }
74  
75      /***
76       * Generates the command line for the JVM
77       *
78       * @param mainClass the fully qualified name of the main class
79       * @param classpath the classpath. If <code>null</code>, uses the
80       * value of the <code>"java.class.path"</code> system property
81       * @param sysProps system properties to pass to the JVM.
82       * @param args the command line arguments. May be <code>null</code>
83       */
84      private static String getCommand(String mainClass, String classpath,
85                                       Properties sysProps, String args) {
86          if (classpath == null) {
87              classpath = System.getProperty("java.class.path");
88          }
89          StringBuffer command = new StringBuffer("java -cp ");
90          command.append(classpath);
91          command.append(" ");
92          if (sysProps != null) {
93              Enumeration names = sysProps.propertyNames();
94              while (names.hasMoreElements()) {
95                  String name = (String) names.nextElement();
96                  String value = sysProps.getProperty(name);
97                  command.append("-D");
98                  command.append(name);
99                  command.append("=");
100                 command.append(value);
101                 command.append(" ");
102             }
103         }
104         command.append(mainClass);
105         if (args != null) {
106             command.append(" ");
107             command.append(args);
108         }
109         return command.toString();
110     }
111 }