# Energy4Java.java

    /*
     * Copyright 2008-2011 Niclas Hedhman. All rights Reserved.
     *
     * 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.bootstrap;

    import org.qi4j.api.Qi4j;
    import org.qi4j.api.structure.Application;
    import org.qi4j.api.structure.ApplicationDescriptor;
    import org.qi4j.spi.Qi4jSPI;

    /**
     * Main bootstrap class for starting Zest and creating new applications.
     * <p>
     * Instantiate this and call one of the factory methods to get started.
     * </p>
     * <p>
     * This class will use the Service Loader mechanism in Java to try to locate a runtime that implements
     * the Qi4jRuntime interface. This avoids a direct dependency from the bootstrap to the runtime.
     * </p>
     */
    public final class Energy4Java
    {
        private Qi4jRuntime runtime;

        public Energy4Java( RuntimeFactory runtimeFactory )
        {
            this( runtimeFactory.createRuntime() );
        }

        public Energy4Java()
        {
            this( new RuntimeFactory.StandaloneApplicationRuntimeFactory().createRuntime() );
        }

        public Energy4Java( Qi4jRuntime runtime )
        {
            if( runtime == null )
            {
                throw new BootstrapException( "Can not create Zest without a Zest Runtime." );
            }
            this.runtime = runtime;
        }

        public ApplicationDescriptor newApplicationModel( ApplicationAssembler assembler )
            throws AssemblyException
        {
            ApplicationAssembly assembly = assembler.assemble( runtime.applicationAssemblyFactory() );

            if( assembly == null )
            {
                throw new AssemblyException( "Application assembler did not return any ApplicationAssembly" );
            }

            try
            {
                ApplicationModelFactory modelFactory = runtime.applicationModelFactory();
                return modelFactory.newApplicationModel( assembly );
            }
            catch( RuntimeException e )
            {
                throw new AssemblyException( "Unable to create Application Model.", e );
            }
        }

        public Application newApplication( ApplicationAssembler assembler, Object... importedServiceInstances )
            throws AssemblyException
        {
            ApplicationDescriptor model = newApplicationModel( assembler );
            return model.newInstance( runtime.spi(), importedServiceInstances );
        }

        public Qi4jSPI spi()
        {
            return runtime.spi();
        }

        public Qi4j api()
        {
            return runtime.spi();
        }
    }