org.apache.nifi.components.resource.ResourceReferences Maven / Gradle / Ivy
/*
* 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.nifi.components.resource;
import java.net.URL;
import java.util.List;
/**
* A representation of zero or more {@link ResourceReference}s
*/
public interface ResourceReferences {
/**
* @return a List representation of all Resource References
*/
List asList();
/**
* @return a list of all Resource References' locations
*/
List asLocations();
/**
* @return a list of all Resource References' URLs
*/
List asURLs();
/**
* @return the number of Resource References held
*/
int getCount();
/**
* Iterates through the Resource References and for any reference that may represent more than one
* resource, flattens the resource into a List of single-entity references. For example, consider that this ResourceReferences
* holds a single ResourceReference, of type DIRECTORY and the referenced directory contains 10 files. Calling {@link #asList()} would
* return a single ResourceReference. But calling flatten() would return a new ResourceReferences type whose {@link #asList()}
* method would return 10 ResourceReference objects, each with a ResourceType of FILE. The flatten operation is not recursive, meaning that if
* a DIRECTORY is flattened, any sub-directories will be dropped. If the contents of the subdirectories are to be retained, use {@link #flattenRecursively()}
* instead.
*
* @return a flattened ResourceReferences
*/
ResourceReferences flatten();
/**
* Recursively iterates through the Resource References and for any reference that may represent more than one
* resource, flattens the resource into a List of single-entity references. For example, consider that this ResourceReferences
* holds a single ResourceReference, of type DIRECTORY and the referenced directory contains 10 files. Calling {@link #asList()} would
* return a single ResourceReference. But calling flatten() would return a new ResourceReferences type whose {@link #asList()}
* method would return 10 ResourceReference objects, each with a ResourceType of FILE. The flatten operation is recursive, meaning that if
* a DIRECTORY is encountered, its reference will be replaced with a new reference for each file, even if that file exists 100 levels deep
* in the directory structure.
*
* @return a flattened ResourceReferences
*/
ResourceReferences flattenRecursively();
}