1 /*
   2  * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package sun.tools.common;
  27 
  28 import java.lang.reflect.Method;
  29 
  30 /**
  31  * A helper class to retrieve the main class name for a running
  32  * Java process.
  33  */
  34 
  35 public interface ProcessHelper {
  36 
  37     /**
  38      * Returns an instance of the ProcessHelper class.
  39      *
  40      * @return ProcessHelper object or null if not supported on this platform.
  41      */
  42     public static ProcessHelper platformProcessHelper() {
  43         try {
  44             Class<?> c = Class.forName("sun.tools.ProcessHelper");
  45             @SuppressWarnings("unchecked")
  46             Method m = c.getMethod("getInstance");
  47             return (ProcessHelper) m.invoke(null);
  48         } catch (ClassNotFoundException e) {
  49             return null;
  50         } catch (ReflectiveOperationException e) {
  51             throw new InternalError(e);
  52         }
  53     }
  54 
  55 
  56     /**
  57      * Returns the main class name for the given Java process
  58      *
  59      * @param pid - process ID (pid)
  60      * @return main class name or null if the main class could not be retrieved
  61      */
  62 
  63     String getMainClass(String pid);
  64 }