/*
 * 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 javax.inject.Singleton;
import java.lang.annotation.Documented;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.Target;

import static java.lang.annotation.RetentionPolicy.RUNTIME;

Defines a singleton bean whose property values are resolved from a PropertyResolver.

The PropertyResolver is typically the Micronaut Environment.

The value() of the annotation is used to indicate the prefix where the configuration properties are located. The class can define properties or fields which will have the configuration properties to them at runtime. 

Complex nested properties are supported via classes that are public static inner classes and are also annotated with ConfigurationProperties.
Author:
Graeme Rocher
Since:
1.0/**
 * <p>Defines a singleton bean whose property values are resolved from a {@link io.micronaut.core.value.PropertyResolver}.</p>
 * <p>
 * <p>The {@link io.micronaut.core.value.PropertyResolver} is typically the Micronaut {@link io.micronaut.context.env.Environment}.</p>
 * <p>
 * <p>The {@link #value()} of the annotation is used to indicate the prefix where the configuration properties are located.
 * The class can define properties or fields which will have the configuration properties to them at runtime.
 * </p>
 * <p>
 * <p>Complex nested properties are supported via classes that are public static inner classes and are also annotated
 * with {@link ConfigurationProperties}.</p>
 *
 * @author Graeme Rocher
 * @since 1.0
 */
@Singleton
@Documented
@Retention(RUNTIME)
@Target({ElementType.TYPE, ElementType.ANNOTATION_TYPE, ElementType.METHOD, ElementType.CONSTRUCTOR})
@ConfigurationReader
public @interface ConfigurationProperties {

    
The prefix to use when resolving properties. The prefix should be defined in kebab case. Example: my-app.foo.
Returns:
The prefix to use to resolve the properties/**
     * The prefix to use when resolving properties. The prefix should be defined in kebab case. Example: my-app.foo.
     *
     * @return The prefix to use to resolve the properties
     */
    @AliasFor(annotation = ConfigurationReader.class, member = "value")
    String value();

    
If the properties of this configuration can also be resolved from the CLI a prefix can be specified.

For example given a prefix value {code server-} and a property called {code port}, Micronaut will attempt
to resolve the value of --server-port when specified on the command line
Returns:
The CLI prefix of the configuration. If a blank string is used then no prefix is appended/**
     * <p>If the properties of this configuration can also be resolved from the CLI a prefix can be specified.</p>
     * <p>
     * <p>For example given a prefix value {code server-} and a property called {code port}, Micronaut will attempt
     * to resolve the value of --server-port when specified on the command line</p>
     *
     * @return The CLI prefix of the configuration. If a blank string is used then no prefix is appended
     */
    String[] cliPrefix() default {};

    
Returns:
The names of the properties to include/**
     * @return The names of the properties to include
     */
    @AliasFor(annotation = ConfigurationReader.class, member = "includes")
    String[] includes() default {};

    
Returns:
The names of the properties to exclude/**
     * @return The names of the properties to exclude
     */
    @AliasFor(annotation = ConfigurationReader.class, member = "excludes")
    String[] excludes() default {};

}