org.constretto.annotation.Configuration Maven / Gradle / Ivy
/*
* Copyright 2008 the original author or 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
*
* 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.constretto.annotation;
import org.constretto.ConfigurationDefaultValueFactory;
import java.lang.annotation.*;
/**
* @author Kaare Nilsen
*/
@Target({ElementType.PARAMETER, ElementType.FIELD})
@Retention(RetentionPolicy.RUNTIME)
@Inherited
public @interface Configuration {
/**
* The expression of the property to lookup in constretto.
*
* It is important that environment prefixes is not used in this attribute
*/
String expression() default "";
/**
* A description of the usage of the property. Not directly used in the runtime environment, but may be
* useful for documentation or monitoring situations
*/
String description() default "";
/**
* States the default value to be injected if no value found associated for the expression specified in the
* expression attribute.
*
* When a default value is set, the required attribute will be ignored.
*/
String defaultValue() default "N/A";
/**
* Use when more complex default values needs to be injected of no value found associated with the expression
* specified in the expression attribute
*/
Class> defaultValueFactory() default EmptyValueFactory.class;
/**
* Declares whether it is required to find the specified property key.
*
* Defaults to true.
*/
boolean required() default true;
//
// helper
//
public static class EmptyValueFactory implements ConfigurationDefaultValueFactory