Process.java

/*
 * Copyright (C) 2011 Google Inc.
 *
 * Licensed 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.ros.internal.system;

import java.lang.management.ManagementFactory;

/**
 * Process-related utility methods.
 *
 * @author khughes@google.com (Keith M. Hughes)
 */
public class Process {

  private Process() {
    // Utility class.
  }

  /**
   * @return PID of node process if available, throws
   *         {@link UnsupportedOperationException} otherwise.
   */
  public static int getPid() {
    // NOTE(kwc): Java has no standard way of getting PID. MF.getName()
    // returns '1234@localhost'.
    try {
      String mxName = ManagementFactory.getRuntimeMXBean().getName();
      int idx = mxName.indexOf('@');
      if (idx > 0) {
        try {
          return Integer.parseInt(mxName.substring(0, idx));
        } catch (NumberFormatException e) {
          return 0;
        }
      }
    } catch (NoClassDefFoundError unused) {
      // Android does not support ManagementFactory. Try to get the PID on
      // Android.
      try {
        return (Integer) Class.forName("android.os.Process").getMethod("myPid").invoke(null);
      } catch (Exception unused1) {
        // Ignore this exception and fall through to the
        // UnsupportedOperationException.
      }
    }
    throw new UnsupportedOperationException();
  }
}