InstallationContext.java

package org.nnsoft.guice.autobind.install;

/*
 *    Copyright 2012 The 99 Software Foundation
 *
 *    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.
 */

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.concurrent.Callable;

/**
 * This class is internally used, to bind Installation Requests and process them
 * sequentially in a predefined order.
 */
public class InstallationContext {

    private final Map<BindingStage, List<Callable<?>>> context = new HashMap<BindingStage, List<Callable<?>>>();

    public void process()
        throws Exception
    {
        for ( BindingStage stage : BindingStage.ORDERED )
        {
            List<Callable<?>> requests = context.get( stage );
            if ( requests != null )
            {
                for ( Callable<?> request : requests )
                {
                    request.call();
                }
            }
        }
    }

    public void add( BindingStage stage, Callable<?> request )
    {
        synchronized ( context )
        {
            List<Callable<?>> requests = context.get( stage );
            if ( requests == null )
            {
                requests = new ArrayList<Callable<?>>();
                context.put( stage, requests );
            }
            requests.add( request );
        }
    }

    public void add( StageableRequest request )
    {
        synchronized ( context )
        {
            List<Callable<?>> requests = context.get( request.getExecutionStage() );
            if ( requests == null )
            {
                requests = new ArrayList<Callable<?>>();
                context.put( request.getExecutionStage(), requests );
            }
            requests.add( request );
        }
    }

    public static interface StageableRequest
        extends Callable<Void>
    {

        BindingStage getExecutionStage();

    }

}