com.yahoo.jdisc.ReferencedResource Maven / Gradle / Ivy
// Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
package com.yahoo.jdisc;
/**
* Utility class for working with reference-counted {@link SharedResource}s.
*
* Sometimes, you may want a method to return both a resource object and
* a {@link ResourceReference} that refers the resource object (for later release of the resource).
* Java methods cannot return multiple objects, so this class provides Pair-like functionality
* for returning both.
*
* Example usage:
*
* ReferencedResource<MyResource> getResource() {
* final ResourceReference ref = resource.refer();
* return new ReferencedResource(resource, ref);
* }
*
* void useResource() {
* final ReferencedResource<MyResource> referencedResource = getResource();
* referencedResource.getResource().use();
* referencedResource.getReference().close();
* }
*
*
* This class implements AutoCloseable, so the latter method may also be written as follows:
*
* void useResource() {
* for (final ReferencedResource<MyResource> referencedResource = getResource()) {
* referencedResource.getResource().use();
* }
* }
*
*
* @author bakksjo
*/
public class ReferencedResource implements AutoCloseable {
private final T resource;
private final ResourceReference reference;
public ReferencedResource(final T resource, final ResourceReference reference) {
this.resource = resource;
this.reference = reference;
}
public T getResource() {
return resource;
}
public ResourceReference getReference() {
return reference;
}
@Override
public void close() {
reference.close();
}
}