Expressions

public interface Expression {

    /**
     * Returns the value of the expression on the given exchange
     *
     * @param exchange the message exchange on which to evaluate the expression
     * @param type the expected type of the evaluation result
     * @return the value of the expression
     */
    <T> T evaluate(Exchange exchange, Class<T> type);
}

public interface Predicate {

    /**
     * Evaluates the predicate on the message exchange and returns true if this
     * exchange matches the predicate
     *
     * @param exchange the message exchange
     * @return true if the predicate matches
     */
    boolean matches(Exchange exchange);

}