org.codehaus.plexus.components.io.resources.PlexusIoResourceCollection Maven / Gradle / Ivy
package org.codehaus.plexus.components.io.resources;
/*
* Copyright 2007 The Codehaus Foundation.
*
* 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.
*/
import java.io.IOException;
import java.io.InputStream;
import java.util.Iterator;
/**
* A resource collection is a set of {@link PlexusIoResource} instances.
*/
public interface PlexusIoResourceCollection extends Iterable {
/**
* Returns an iterator over the resources in the collection.
* @return An iterator
* @throws java.io.IOException .
*/
Iterator getResources() throws IOException;
/**
* Returns the resources as a stream.
* @return A stream for functional iteration
*/
Stream stream();
/**
* Returns the resources suggested name. This is used for
* integrating file mappers.
* @param resource A resource, which has been obtained by
* calling {@link #getResources()}.
* @return The resource name. If it is a file, it should be normalized to platform separators
*/
String getName(PlexusIoResource resource);
/**
* Returns the collections last modification time. For a
* collection of files, this might be the last modification
* time of the file, which has been modified at last. For an
* archive file, this might be the modification time of the
* archive file.
* @return {@link PlexusIoResource#UNKNOWN_MODIFICATION_DATE},
* if the collections last modification time is unknown,
* otherwise the last modification time in milliseconds.
* @throws java.io.IOException .
*/
long getLastModified() throws IOException;
/**
* Returns an input stream for the provided resource, with stream transformers applied
* @param resource The resources
* @return A possibly transformed resource
* @throws IOException when something goes bad
*/
InputStream getInputStream(PlexusIoResource resource) throws IOException;
/**
* Resolves the supplied resource into a "real" resource. Resolving
* means applying input transformations
* Returns an input stream for the provided resource, with stream transformers applied
* @param resource The resources
* @return A possibly transformed resource
* @throws IOException when something goes bad
*/
PlexusIoResource resolve(PlexusIoResource resource) throws IOException;
/**
* Indicates if this collection supports concurrent access to its resources.
* Some resource collections (like tar files) may not support efficient random access
* or seek operation so implementations that represent such collections may not be able
* to provide concurrent access to its resources. If implementation returns {@code false},
* then it is not safe to access its methods and resources in concurrent fashion.
* For example it is not safe to read from two resources in two concurrent threads,
* to read a resource and iterate over the iterator returned by {@link #getResources()}
* in two concurrent threads, etc.
*
Please note that this method indicates concurrent support only for the collection,
* not for the individual resources. This means there is no guarantee that
* the resources returned by {@link #resolve(PlexusIoResource)} or the input stream
* returned by {@link #getInputStream(PlexusIoResource)} are thread-safe,
* even if {@code true} is returned.
* @return {@code true} if this collection supports concurrent access,
* otherwise {@code false}
*/
boolean isConcurrentAccessSupported();
}