| /* |
| * Copyright (c) 2009, 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.apache.zest.api.service.qualifier; |
| |
| import java.lang.annotation.Documented; |
| import java.lang.annotation.Retention; |
| import java.lang.annotation.RetentionPolicy; |
| import org.apache.zest.api.service.ServiceReference; |
| import org.apache.zest.functional.Specification; |
| |
| /** |
| * Filter services based on Meta Info being declared on the Service. |
| * <p> |
| * Meta Info of any type can be set on the service during assembly, e.g.; |
| * </p> |
| * <pre><code> |
| * module.addService( MyService.class ).setMetaInfo( new MyCustomInfo(someData) ); |
| * </code></pre> |
| * <p> |
| * and then at an injection point you can do this: |
| * </p> |
| * <pre><code> |
| * @Service @HasMetaInfo(MyCustomInfo.class) MyService service; |
| * </code></pre> |
| * <p> |
| * to get only a service that has a MyCustomInfo instance set as meta info. |
| * </p> |
| */ |
| @Retention( RetentionPolicy.RUNTIME ) |
| @Qualifier( HasMetaInfo.HasMetaInfoQualifier.class ) |
| @Documented |
| public @interface HasMetaInfo |
| { |
| /** |
| * The Class(es) needed to have been defined in the Service meta info for a qualifier to evaluate true. |
| * |
| * @return One or more classes that should be defined in the service's meta info for the service to be considered |
| * qualified. If more than one class is defined, the {@code anded()} parameter will define if they must be |
| * AND'ed or OR'ed together. |
| */ |
| Class[] value(); |
| |
| /** |
| * True if the Classes defined in the value() field should be AND'ed instead of OR'ed. |
| * |
| * @return If true, all the Class types defined in {@code value()} must be defined for the service for it to be |
| * qualified. If false, if any of the Class types defined in {@code value()} is defined for the service |
| * the service is qualified. |
| */ |
| boolean anded() default false; |
| |
| /** |
| * HasMetaInfo Annotation Qualifier. |
| * See {@link HasMetaInfo}. |
| */ |
| public static class HasMetaInfoQualifier |
| implements AnnotationQualifier<HasMetaInfo> |
| { |
| @Override |
| public <T> Specification<ServiceReference<?>> qualifier( final HasMetaInfo hasMetaInfo ) |
| { |
| return new Specification<ServiceReference<?>>() |
| { |
| @Override |
| @SuppressWarnings( {"raw", "unchecked"} ) |
| public boolean satisfiedBy( ServiceReference<?> service ) |
| { |
| for( Class metaInfoType : hasMetaInfo.value() ) |
| { |
| Object metaInfo = service.metaInfo( metaInfoType ); |
| if( hasMetaInfo.anded() ) |
| { |
| if( metaInfo == null ) |
| { |
| return false; |
| } |
| } |
| else |
| { |
| if( metaInfo != null ) |
| { |
| return true; |
| } |
| } |
| } |
| return false; |
| } |
| }; |
| } |
| } |
| } |