Drools7服务之KieServices

KieService ks = KieServices.Factory.get();

package org.kie.api;

import org.kie.api.internal.utils.ServiceRegistry;


/**
 * <p>
 * The KieServices is a thread-safe singleton acting as a hub giving access to the other
 * Services provided by Kie. As general rule a getX() method just returns a reference to another
 * singleton while a newX() one creates a new instance.
 * </p>
 * <p>
 * It is possible to obtain a KieServices reference via its Factory as it follows
 * </p>
 * <pre>
 * KieServices kieServices = KieServices.Factory.get();
 * </pre>
 */
public interface KieServices {

    /**
     * Returns a reference to the KieServices singleton
     */
    static KieServices get() {
        return Factory.get();
    }

    /**
     * A Factory for this KieServices
     */
    class Factory {
        private static class LazyHolder {
            private static KieServices INSTANCE = ServiceRegistry.getInstance().get(KieServices.class);
        }

        /**
         * Returns a reference to the KieServices singleton
         */
        public static KieServices get() {
            return LazyHolder.INSTANCE;
        }
    }
}