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The module that is an implementation of the Dependency Injection design pattern, that is integrated to the RxMicro framework.
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/*
 * Copyright (c) 2020. https://rxmicro.io
 *
 * 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 io.rxmicro.cdi;

import io.rxmicro.cdi.resource.ResourceConverter;

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

import static java.lang.annotation.ElementType.CONSTRUCTOR;
import static java.lang.annotation.ElementType.FIELD;
import static java.lang.annotation.ElementType.METHOD;
import static java.lang.annotation.ElementType.PARAMETER;
import static java.lang.annotation.RetentionPolicy.CLASS;

/**
 * Indicates the need to inject the external resource into the annotated class field or method parameter.
 *
 * 
 * External resource is:
 * 

 *     File
 *     Directory
 *     Classpath resource
 *     URL Resource
 *     etc
 * 
 *
 * 
 * The RxMicro framework uses blocking API to inject resource during startup!
 *
 * @author nedis
 * @see Inject
 * @see Autowired
 * @since 0.6
 */
@Documented
@Retention(CLASS)
@Target({FIELD, CONSTRUCTOR, METHOD, PARAMETER})
public @interface Resource {

    /**
     * If {@code true}, and the appropriate resource is not found, the RxMicro framework will skip injection of this
     * method or field rather than produce an error.
     *
     * 

     * When applied to a field, any default value already assigned to the field will remain for optional injection.
     *
     * 

     * (The RxMicro framework will not actively null out the field).
     *
     * @return {@code true} if current injection point is optional
     */
    boolean optional() default false;

    /**
     * Returns the resource path.
     *
     * 

     * Example of valid resource paths:
     * 

     *     {@code /home/rxmicro/config.json}
     *     {@code /home/rxmicro/config.properties}
     *     {@code file:///home/rxmicro/config.json}
     *     {@code file:///home/rxmicro/config.properties}
     *     {@code classpath:config.json}
     *     {@code classpath:config.properties}
     * 
     *
     * @return the resource path
     */
    String value();

    /**
     * Returns the custom resource converter class.
     *
     * 
     * If converter class is not specified, the RxMicro framework tries to detect valid resource converter automatically.
     *
     * 

     * Autodetect resource converter rules:
     * 

     *     
     *         {@link io.rxmicro.cdi.resource.ClasspathJsonArrayResourceConverter} is used if:
     *         
     *             Resource path starts with {@code classpath:} prefix
     *             Resource path ends with {@code json} extension
     *             Annotated by @{@link Resource} annotation field has {@link java.util.List}{@code