org.glassfish.cluster.ssh.util.SSHUtil Maven / Gradle / Ivy

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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
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 * Copyright 1997-2010 Sun Microsystems, Inc. All rights reserved.
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package org.glassfish.cluster.ssh.util;

import com.trilead.ssh2.Connection;

import java.util.ArrayList;
import java.util.List;

/**
 * @author Rajiv Mordani
 */
public class SSHUtil {
    private static final List activeConnections = 
                            new ArrayList();

   /**
       * Closes all the registered connections.
       */
      private static synchronized void closeRegisteredConnections() {
          for (Connection connection : activeConnections) {
              connection.close();
          }
          activeConnections.clear();
      }

   /**
       * Registers a connection for cleanup when the plugin is stopped.
       *
       * @param connection The connection.
       */
      public static synchronized void register(Connection connection) {
          if (!activeConnections.contains(connection)) {
              activeConnections.add(connection);
          }
      }

   /**
       * Unregisters a connection for cleanup when the plugin is stopped.
       *
       * @param connection The connection.
       */
      public static synchronized void unregister(Connection connection) {
          connection.close();
          activeConnections.remove(connection);
      }

   /**
       * Convert empty string to null.
       */
      public static String checkString(String s) {
          if(s==null || s.length()==0)    return null;
          return s;
      }

}