core/runtime/src/test/java/org/apache/zest/runtime/injection/ServiceInjectionTest.java

/*
 * Copyright (c) 2007, Rickard Öberg. 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.apache.zest.runtime.injection;

import java.io.Serializable;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import org.junit.Test;
import org.apache.zest.api.activation.ActivationException;
import org.apache.zest.api.common.ConstructionException;
import org.apache.zest.api.common.Optional;
import org.apache.zest.api.injection.scope.Service;
import org.apache.zest.api.mixin.Mixins;
import org.apache.zest.api.object.ObjectFactory;
import org.apache.zest.api.service.ServiceComposite;
import org.apache.zest.api.service.ServiceImporterException;
import org.apache.zest.api.service.ServiceReference;
import org.apache.zest.api.service.qualifier.AnnotationQualifier;
import org.apache.zest.api.service.qualifier.IdentifiedBy;
import org.apache.zest.api.service.qualifier.Qualifier;
import org.apache.zest.bootstrap.ApplicationAssembly;
import org.apache.zest.bootstrap.AssemblyException;
import org.apache.zest.bootstrap.LayerAssembly;
import org.apache.zest.bootstrap.ModuleAssembly;
import org.apache.zest.bootstrap.ServiceDeclaration;
import org.apache.zest.bootstrap.SingletonAssembler;
import org.apache.zest.functional.Specification;

import static org.junit.Assert.assertEquals;
import static org.apache.zest.api.common.Visibility.application;
import static org.apache.zest.api.common.Visibility.layer;

/**
 * Test the @Service injection annotation
 */
public class ServiceInjectionTest
{
    @Test
    public void testInjectService()
        throws Exception
    {
        SingletonAssembler assembly = new SingletonAssembler()
        {
            public void assemble( ModuleAssembly module )
                throws AssemblyException
            {
                module.services( MyServiceComposite.class )
                    .identifiedBy( "Foo" )
                    .setMetaInfo( new ServiceName( "Foo" ) );
                module.services( MyServiceComposite2.class )
                    .identifiedBy( "Bar" )
                    .setMetaInfo( new ServiceName( "Bar" ) );
                module.services( StringService.class, LongService.class );
                module.objects( ServiceUser.class );
            }
        };

        testInjection( assembly );
    }

    private void testInjection( SingletonAssembler assembly )
    {
        ObjectFactory factory = assembly.module();
        ServiceUser user = factory.newObject( ServiceUser.class );

        assertEquals( "X", user.testSingle() );
        assertEquals( "Foo", user.testIdentity() );
        assertEquals( "XX", user.testIterable() );
        assertEquals( "FooX", user.testServiceReference() );
        assertEquals( "FooXBarX", user.testIterableServiceReferences() );
        assertEquals( "Bar", user.testQualifier() );
        assertEquals( "A", user.testStringIterable() );
        assertEquals( new Long( 1L ), user.testLongIterable() );
    }

    @Test
    public void testInjectionServiceBetweenModules()
        throws ActivationException, AssemblyException
    {
        SingletonAssembler assembly = new SingletonAssembler()
        {
            public void assemble( ModuleAssembly module )
                throws AssemblyException
            {
                module.services( MyServiceComposite.class )
                    .identifiedBy( "Foo" )
                    .setMetaInfo( new ServiceName( "Foo" ) );
                module.services( StringService.class, LongService.class );
                module.objects( ServiceUser.class );

                ModuleAssembly module2 = module.layer().module( "Other module" );
                ServiceDeclaration service2Decl = module2.services( MyServiceComposite.class );
                service2Decl.identifiedBy( "Bar" ).setMetaInfo( new ServiceName( "Bar" ) ).visibleIn( layer );

                ServiceDeclaration service3Decl = module2.services( MyServiceComposite2.class );
                service3Decl.identifiedBy( "Boo" ).setMetaInfo( new ServiceName( "Boo" ) );
            }
        };

        testInjection( assembly );
    }

    @Test
    public void testInjectionServiceBetweenLayers()
        throws ActivationException, AssemblyException
    {
        SingletonAssembler assembly = new SingletonAssembler()
        {
            public void assemble( ModuleAssembly module )
                throws AssemblyException
            {
                module.services( MyServiceComposite.class )
                    .identifiedBy( "Foo" )
                    .setMetaInfo( new ServiceName( "Foo" ) );
                module.services( StringService.class, LongService.class );
                LayerAssembly layerAssembly = module.layer();
                module.objects( ServiceUser.class );

                ApplicationAssembly applicationAssembly = layerAssembly.application();
                LayerAssembly layer2Assembly = applicationAssembly.layer( "Other layer" );
                layerAssembly.uses( layer2Assembly );

                ModuleAssembly module2 = layer2Assembly.module( "Other module" );

                ServiceDeclaration service2Decl = module2.services( MyServiceComposite2.class );
                service2Decl.identifiedBy( "Bar" ).setMetaInfo( new ServiceName( "Bar" ) ).visibleIn( application );
            }
        };

        testInjection( assembly );
    }

    @Test( expected = ConstructionException.class )
    public void testMissingServiceDependency()
        throws ActivationException, AssemblyException
    {
        // No service fulfils the dependency injection -> fail to create application
        new SingletonAssembler()
        {
            public void assemble( ModuleAssembly module )
                throws AssemblyException
            {
                module.objects( ServiceUser.class );
            }
        }.module().newObject( ServiceUser.class );
    }

    @Mixins( MyServiceMixin.class )
    public static interface MyServiceComposite
        extends MyService, ServiceComposite
    {
    }

    public static interface MyServiceComposite2
        extends MyServiceComposite
    {
    }

    public static interface MyService
    {
        String doStuff();
    }

    public static class MyServiceMixin
        implements MyService
    {

        public String doStuff()
        {
            return "X";
        }
    }

    public static class ServiceUser
        extends AbstractServiceUser<String>
    {
    }

    public static class AbstractServiceUser<T>
    {
        @Service
        MyService service;
        @Service
        MyServiceComposite serviceComposite;
        @Service
        Iterable<MyService> services;
        @Service
        ServiceReference<MyService> serviceRef;
        @Service
        Iterable<ServiceReference<MyService>> serviceRefs;

        @Service
        @IdentifiedBy( "Bar" )
        ServiceReference<MyService> qualifiedService;

        @Service
        @IdentifiedBy( "Bar" )
        Iterable<ServiceReference<MyService>> qualifiedServiceRefs;

        @Optional
        @Service
        MyServiceMixin optionalService12;

        @Service
        Foo<Long> longService;

        @Service
        Foo<T> stringService;

        public String testSingle()
        {
            return service.doStuff();
        }

        public String testIdentity()
        {
            return serviceComposite.identity().get();
        }

        public String testIterable()
        {
            String str = "";
            for( MyService myService : services )
            {
                str += myService.doStuff();
            }
            return str;
        }

        public String testServiceReference()
            throws ServiceImporterException
        {
            ServiceName info = serviceRef.metaInfo( ServiceName.class );
            return info.getName() + serviceRef.get().doStuff();
        }

        public String testIterableServiceReferences()
            throws ServiceImporterException
        {
            String str = "";
            for( ServiceReference<MyService> serviceReference : serviceRefs )
            {
                str += serviceReference.metaInfo( ServiceName.class ).getName();
                str += serviceReference.get().doStuff();
            }
            return str;
        }

        public String testQualifier()
        {
            return qualifiedService.metaInfo( ServiceName.class ).getName();
        }

        public String testQualifiedServices()
        {
            String str = "";
            for( ServiceReference<MyService> qualifiedServiceRef : qualifiedServiceRefs )
            {
                str += qualifiedServiceRef.metaInfo( ServiceName.class ).getName();
            }
            return str;
        }

        public T testStringIterable()
        {
            return stringService.get();
        }

        public Long testLongIterable()
        {
            return longService.get();
        }
    }

    @Qualifier( NamedSelector.class )
    @Retention( RetentionPolicy.RUNTIME )
    public @interface Named
    {
        public abstract String value();
    }

    public static final class NamedSelector
        implements AnnotationQualifier<Named>
    {
        public <T> Specification<ServiceReference<?>> qualifier( final Named named )
        {
            return new Specification<ServiceReference<?>>()
            {
                public boolean satisfiedBy( ServiceReference<?> service )
                {
                    ServiceName serviceName = service.metaInfo( ServiceName.class );
                    return ( serviceName != null && serviceName.getName().equals( named.value() ) );
                }
            };
        }
    }

    public static class ServiceName
        implements Serializable
    {
        private String name;

        public ServiceName( String name )
        {
            this.name = name;
        }

        public String getName()
        {
            return name;
        }
    }

    public static interface Foo<T>
    {
        T get();
    }

    @Mixins( StringService.Mixin.class )
    public static interface StringService
        extends Foo<String>, ServiceComposite
    {
        class Mixin
            implements Foo<String>
        {
            @Override
            public String get()
            {
                return "A";
            }
        }
    }

    @Mixins( LongService.Mixin.class )
    public static interface LongService
        extends Foo<Long>, ServiceComposite
    {
        class Mixin
            implements Foo<Long>
        {
            @Override
            public Long get()
            {
                return 1L;
            }
        }
    }
}