simpleinport.java

j2me实现的移动机器人代码（Java实现）

package name.lxm.robot.arch;


public class SimpleInPort implements Port
{
	String port_name;
	Object value;
	long update_timestamp = System.currentTimeMillis();
	long valid_duration = 0;
	long update_level = 0;
	boolean bReady = false;
	Module module = null;
	ValueUpdateListener listener = null;
	
	public SimpleInPort(Module module, String port_name)
	{
		this.module = module;
		this.port_name = port_name;
	}
	
	public String getPortName()
	{
		return port_name;
	}
	
	public int getPortType()
	{
		return PT_I;
	}
	
	public void setValue(Module m, Object v, long duration)
	{
		if(m.getLayer() >= update_level || (System.currentTimeMillis() - update_timestamp) > valid_duration)
		{
			//do not care about the valide duration
			value = v;
			valid_duration = duration;
			update_timestamp = System.currentTimeMillis();
			bReady = true;
			if(listener != null)
				listener.valueUpdated();
		}
	}
	
	/**
	 * Get the value from the wire, ignoring the life limitation
	 * @return the value
	 */
	public Object getValue()
	{
		if(bReady)
		{
			bReady = false;
			return value;
		}
		return null;
	}

	/**
	 * Get the value from the wire, considering the life limitation
	 * @return the value
	 */
	public Object getValue2()
	{
		if((System.currentTimeMillis()-update_timestamp)<=valid_duration)
		{
			return value;
		}
		return null;
	}

	/**
	 * Register a listener, so that when an value come in,
	 * the owner of the listener can be notified; 
	 * No need to unregister this listener; however if you
	 * really want to remove it, please use null as the input
	 * parameter.
	 *
	 * @param l - ValueUpdateListener
	 */
	public void registerListener(ValueUpdateListener l)
	{
		listener = l;
	}
}