modules/configuration-api/src/main/java/org/apache/ignite/configuration/annotation/Value.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.ignite.configuration.annotation;

import java.lang.annotation.Documented;
import java.lang.annotation.Retention;
import java.lang.annotation.Target;

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

/**
 * This annotation marks configuration schema field as a configuration tree leaf.
 * Every field annotated with this annotation will produce a {@code DynamicProperty} field in generated configuration
 * class.
 * <p>
 * Type must be one of the following (or array of one of the following):
 * <ul>
 *     <li>boolean</li>
 *     <li>int</li>
 *     <li>long</li>
 *     <li>double</li>
 *     <li>String</li>
 * </ul>
 */
@Target(FIELD)
@Retention(RUNTIME)
@Documented
public @interface Value {
    /**
     * Indicates that the current configuration value has a default value. Value itself is derived from the instantiated object
     * of a corresponding schema type. This means that the default is not necessarily a constant value.
     * @return {@code hasDefault} flag value.
     */
    boolean hasDefault() default false;
}