// 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.tapestry5.ioc.annotations; import java.lang.annotation.Documented; import java.lang.annotation.Retention; import java.lang.annotation.Target; import static java.lang.annotation.ElementType.*; import static java.lang.annotation.RetentionPolicy.RUNTIME; import static org.apache.tapestry5.ioc.annotations.AnnotationUseContext.*; /** * This annotation serves is something of the Swiss Army knife for operations related to injection of dependencies into * an arbitrary method of Java Bean. * * * It marks parameters that should be injected in the IoC container, and it marks fields that should be injected inside * Tapestry components. * * In terms of the IoC container; normally, resources take precedence over annotations when injecting. The Inject * annotation overrides this default, forcing the resolution of the parameters value via the master * {@link org.apache.tapestry5.ioc.ObjectProvider}, even when the parameter's type matches a type that is normally a * resource. * * For service implementations, module classes, and other objects constructed via * {@link org.apache.tapestry5.ioc.ObjectLocator#autobuild(Class)}, this annotation indicates that an injection is * desired on the field, as with fields of a Tapestry component. * * In terms of the IoC container, the Inject annotation is only used on parameters to service builder methods (and * contributor and decorator methods) and on module class constructors. constructors. However, inside Tapestry * components (<em>and only inside components</em>), it may be applied to fields. On fields that require injection, the * Inject annotation is <em>required</em>. * * Finally, on a constructor, this is used to indicate <em>which</em> constructor should be used when more than one is * available. * * @see org.apache.tapestry5.ioc.ObjectProvider */ @Target( { PARAMETER, FIELD, CONSTRUCTOR }) @Retention(RUNTIME) @Documented @UseWith( { COMPONENT, MIXIN, PAGE, SERVICE }) public @interface Inject { }