# AbstractEnabledCircuitBreakerAvailability.java

    /*
     * Copyright 2009-2010 Rickard Öberg AB
     *
     * Licensed under the Apache License, Version 2.0 (the "License");
     * you may not use this file except in compliance with the License.
     * You may obtain a copy of the License at
     *
     *     http://www.apache.org/licenses/LICENSE-2.0
     *
     * Unless required by applicable law or agreed to in writing, software
     * distributed under the License is distributed on an "AS IS" BASIS,
     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     * See the License for the specific language governing permissions and
     * limitations under the License.
     */
    package org.qi4j.library.circuitbreaker.service;

    import org.qi4j.api.configuration.Configuration;
    import org.qi4j.api.configuration.Enabled;
    import org.qi4j.api.injection.scope.This;
    import org.qi4j.api.mixin.Mixins;
    import org.qi4j.api.service.Availability;
    import org.qi4j.library.circuitbreaker.CircuitBreaker;

    /**
     * Abstract composite that determines Availability by
     * checking the Enabled configuration and a CircuitBreaker.
     *
     * To use this, the service must implement ServiceCircuitBreaker, and its ConfigurationComposite
     * must extend Enabled.
     */
    @Mixins( AbstractEnabledCircuitBreakerAvailability.Mixin.class )
    public interface AbstractEnabledCircuitBreakerAvailability
            extends Availability
    {

        class Mixin
                implements Availability
        {

            @This
            Configuration<Enabled> config;

            @This
            ServiceCircuitBreaker circuitBreaker;

            @Override
            public boolean isAvailable()
            {
                return config.get().enabled().get() && circuitBreaker.circuitBreaker().status() == CircuitBreaker.Status.on;
            }

        }

    }