org.miv.mbox.net.MBoxLocator Maven / Gradle / Ivy

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The message box acts as a buffer for incoming messages. Its major property is to be usable from any thread. This allows any external source to post any message at any time without having to wonder about synchronisation.
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package org.miv.mbox.net;

/**
 * Address of a message box.
 *
 * An object locator is made of three parts:
 * 
 * 	the host name,
 * 	the port,
 * 	the message box name.
 * 
 *
 * Some object locators only identify hosts when the name is not set. This
 * correspond to what is called the "hostId". An host id is made according to
 * the pattern "//" + hostname + ":" + port.
 *
 * @author Antoine Dutot
 * @since 20040624
 */
public class MBoxLocator
	implements java.io.Serializable
{
// Attributes

	private static final long serialVersionUID = 145871486067935485L;

	/**
	 * Host name of the URL.
	 */
	protected String hostname;

	/**
	 * Port of the URL.
	 */
	protected int port;

	/**
	 * Identifier part of the URL.
	 */
	protected String name;

	/**
	 * Computed host id (Host and port without the name) to avoid recreating it.
	 */
	protected String hostId;

// Constructors

	/**
	 * New locator according to the host name and port only.
	 * @param hostname Computer name.
	 * @param port Network port number.
	 */
	public
	MBoxLocator( String hostname, int port )
	{
		this( hostname, port, "" );
	}

	/**
	 * New locator according to the host name, port and message box name.
	 * @param hostname Computer name.
	 * @param port Network port number.
	 * @param name Message box identifier.
	 */
	public MBoxLocator( String hostname, int port, String name )
	{
		this.hostname = hostname;
		this.port     = port;
		this.name     = name;
		this.hostId   = "//" + hostname + ":" + port;
	}

	/**
	 * New locator created by cutting the given string into fields. The expected
	 * format can be one of:
	 * 
	 * 		"//" + hostname + ":" + port + "/" name
	 * 		"//" + hostname + "/" name
	 * 		"//" + hostname + ":" + port
	 * 		"//" + hostname
	 * 
	 * @param locator_string The string to cut in fields.
	 * @throws IllegalArgumentException If the string does not complies with the
	 * expected format.
	 */
	public MBoxLocator( String locator_string )
		throws IllegalArgumentException
	{
		int n1 = -1, n2 = -1, n3 = -1, n4 = -1;
		String s_port = "0";

		n1 = locator_string.indexOf( '/' );

		if( n1 < 0 )
			throw new IllegalArgumentException( "invalid locator string '" + locator_string + "'" );

		n2 = locator_string.indexOf( '/', n1 + 1 );

		if( n2 < 0 )
			throw new IllegalArgumentException( "invalid locator string '" + locator_string + "'" );
	
		n3 = locator_string.indexOf( ':', n2 + 1 );

		if( n3 < 0 )
		{
			n3 = locator_string.indexOf( '/', n2 + 1 );

			if( n3 < 0 )
				throw new IllegalArgumentException( "invalid locator string '" + locator_string + "'" );
		}
		else
		{
			n4 = locator_string.indexOf( '/', n3 + 1 );

			if( n4 < 0 )
				throw new IllegalArgumentException( "invalid locator string '" + locator_string + "'" );
		}

		hostname = locator_string.substring( n2 + 1, n3 );

		if( n4 >= 0 )
		{
			s_port = locator_string.substring( n3 + 1, n4 );

			if( n4 < locator_string.length() - 1 )
			     name = locator_string.substring( n4 + 1 );
			else name = "";
		}
		else
		{
			if( n3 < locator_string.length() - 1 )
			     name = locator_string.substring( n3 + 1 );
			else name = "";
		}

		try
		{
			port = Integer.parseInt( s_port );
		}
		catch( NumberFormatException e )
		{
			throw new IllegalArgumentException( "invalid locator string (invalid port) '" + locator_string + "'" );
		}

		this.hostId = "//" + hostname + ":" + port;
	}

// Access

	/**
	 * Host name part.
	 * @return the host name only.
	 */
	public String getHostname()
	{
		return hostname;
	}

	/**
	 * Port of this locator.
	 * @return the port only.
	 */
	public int getPort()
	{
		return port;
	}

	/**
	 * Name of this locator.
	 * @return the message box name only.
	 */
	public String getName()
	{
		return name;
	}

	/**
	 * String containing only the hostname and port under the form
	 * "//hostname:port". Two objects on the same host will have the same host
	 * identifier.
	 * @return The host identifier.
	 */
	public String getHostId()
	{
		return hostId;
	}

	@Override
	public String toString()
	{
		if( port > 0 )
		     return "//" + hostname + ":" + port + "/" + name;
		else return "//" + hostname + "/" + name;
	}

// Command

	/**
	 * Change the host name of this locator.
	 * @param hostname Hostname of this locator.
	 */
	public void setHostname( String hostname )
	{
		this.hostname = hostname;
		this.hostId   = "//" + hostname + ":" + port;
	}
	
	/**
	 * Change the port of this locator.
	 * @param port Port of this locator.
	 */
	public void setPort( int port )
	{
		this.port = port;
		this.hostId = "//" + hostname + ":" + port;
	}

	/**
	 * Change the message box name of this locator.
	 * @param name Name of this locator.
	 */
	public void setName( String name )
	{
		this.name = name;
	}
}