io.micronaut.context.annotation.EachProperty Maven / Gradle / Ivy
/*
* Copyright 2017-2020 original authors
*
* 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
*
* https://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 io.micronaut.context.annotation;
import static java.lang.annotation.RetentionPolicy.RUNTIME;
import javax.inject.Singleton;
import java.lang.annotation.Documented;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.Target;
/**
* This annotation allows driving the production of {@link Bean} definitions from either configuration or the
* presence of another bean definition
*
*
For example:
*
* {@literal @}EachProperty("foo.bar")
* public class ExampleConfiguration {
* }
*
*
*
In the above example a new {@code ExampleConfiguration} bean will be created for each item under the
* {@code foo.bar} key in application configuration
*
*
A reference to the configuration entry name can be obtained with the {@link Parameter} annotation applied to a
* constructor argument:
*
* {@literal @}EachProperty("foo.bar")
* public class ExampleConfiguration {
* ExampleConfiguration({@literal @}Parameter String name) {
* ...
* }
* }
*
*
*
In the above example for a configuration property of {@code foo.bar.test}, the value of the {@code name} argument
* will be {@code "test"}
*
*
The bean is created as a singleton with a {@link javax.inject.Named} qualifier matching the configuration entry
* name, thus allowing retrieval with:
*
* ExampleConfiguration exampleConfiguration = applicationContext.getBean(ExampleConfiguration.class, Qualifiers.byName("test"));
*
*
*
Or alternatively dependency injection via the {@link javax.inject.Named} qualifier.
*
*
This annotation is typically used in conjunction with {@link EachBean}. For example, one can drive the
* configuration of other beans with the {@link EachBean} annotation:
*
* {@literal @}EachBean(ExampleConfiguration)
* {@literal @}Singleton
* public class ExampleBean {
* ExampleBean(ExampleConfiguration config) {
* ...
* }
* }
*
*
* @author Graeme Rocher
* @see EachBean
* @see ConfigurationProperties
* @since 1.0
*/
@Documented
@Retention(RUNTIME)
@Target({ElementType.METHOD, ElementType.TYPE})
@Singleton
@ConfigurationReader
public @interface EachProperty {
/**
* Defines the property this {@link EachProperty} is driven by. Should be in kebab case form. Example: "my-app.bar".
*
* @return The property that this bean is driven by
*/
@AliasFor(annotation = ConfigurationReader.class, member = "value")
String value();
/**
* @return The name of the key returned by {@link #value()} that should be regarded as the {@link Primary} bean
*/
String primary() default "";
/**
* @return The names of the properties to include
*/
@AliasFor(annotation = ConfigurationReader.class, member = "includes")
String[] includes() default {};
/**
* @return The names of the properties to exclude
*/
@AliasFor(annotation = ConfigurationReader.class, member = "excludes")
String[] excludes() default {};
/**
* @return True if the beans should be bound from a list. By default {@link EachProperty} binds to a map where
* the key is a string and the value is an instance of the annotated class.
*/
boolean list() default false;
}