Class PreparedEventExpression

  • All Implemented Interfaces:
    java.io.Serializable

    public class PreparedEventExpression
    extends EventExpression
    implements java.io.Serializable

    Instances of this class are created from PreparedEventExpressionTemplate objects. The parameter fields of the PreparedEventExpression can then be filled in to create a fully-qualified event expression, to which MatchListener objects can be attached.

    For example, the statement:

    PreparedEventExpressionTemplate et = new PreparedEventExpressionTemplate("on NewsItem(?, *):news -> StockTick(?, *)");
    
     
    creates a template with two parameters, indicated by the '?' characters in the template string. The template may then be instantiated:
    PreparedEventExpression pex = et.getInstance();
     pex.setString(0, "ACME");
     pex.setString(1, "ACME");
     
    The PreparedEventExpression object may then have MatchListener objects attached to it as usual. In this example the matching NewsItem event is co-assigned to the variable called news. This means that the NewsItem event that caused the match will be available to the MatchListener from the fired MatchEvent by calling evt.getMatchingEvent("news");

    When the expression is matched, all registered listeners will be informed. An object implementing the MatchListener interface may be registered by calling the addMatchListener method, and deregistered by calling the removeMatchListener method.

    See Also:
    Serialized Form
    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      void addMatchListener​(MatchListener listenerToAdd)
      Add a listener to be notified when the match occurs for this event expression.
      void removeAllMatchListeners()
      Remove all previously registered match listeners.
      void setBoolean​(int position, boolean value)
      Set a Boolean type parameter in the PreparedEventExpression.
      void setDouble​(int position, double value)
      Set a double type parameter in the PreparedEventExpression.
      void setLocation​(int position, Location value)
      Set a Location type parameter in the PreparedEventExpression.
      void setLong​(int position, long value)
      Set a long type parameter in the PreparedEventExpression.
      void setString​(int position, java.lang.String value)
      Set a string type parameter in the PreparedEventExpression.
      java.lang.String toString()
      Get the String value of the PreparedEventExpression,
      • Methods inherited from class java.lang.Object

        equals, getClass, hashCode, notify, notifyAll, wait, wait, wait
    • Method Detail

      • setDouble

        public void setDouble​(int position,
                              double value)
                       throws PreparedEventExpressionException
        Set a double type parameter in the PreparedEventExpression.
        Parameters:
        position - Parameter position with the expression template, counting from zero.
        value - The double value of the parameter.
        Throws:
        PreparedEventExpressionException
      • setLong

        public void setLong​(int position,
                            long value)
                     throws PreparedEventExpressionException
        Set a long type parameter in the PreparedEventExpression.
        Parameters:
        position - Parameter position with the expression template, counting from zero.
        value - The long value of the parameter.
        Throws:
        PreparedEventExpressionException
      • setString

        public void setString​(int position,
                              java.lang.String value)
                       throws PreparedEventExpressionException
        Set a string type parameter in the PreparedEventExpression.
        Parameters:
        position - Parameter position with the expression template, counting from zero.
        value - The string value of the parameter.
        Throws:
        PreparedEventExpressionException
      • setBoolean

        public void setBoolean​(int position,
                               boolean value)
                        throws PreparedEventExpressionException
        Set a Boolean type parameter in the PreparedEventExpression.
        Parameters:
        position - Parameter position with the expression template, counting from zero.
        value - The Boolean value of the parameter.
        Throws:
        PreparedEventExpressionException
      • addMatchListener

        public void addMatchListener​(MatchListener listenerToAdd)
        Add a listener to be notified when the match occurs for this event expression.
        Overrides:
        addMatchListener in class EventExpression
        Parameters:
        listenerToAdd - an object implementing the MatchListener interface to be notified when matches occur for this expression.