org.apache.hadoop.fs.impl.BackReference 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.hadoop.fs.impl;
import javax.annotation.Nullable;
/**
* Holds reference to an object to be attached to a stream or store to avoid
* the reference being lost to GC.
*/
public class BackReference {
private final Object reference;
public BackReference(@Nullable Object reference) {
this.reference = reference;
}
/**
* is the reference null?
* @return true if the ref. is null, else false.
*/
public boolean isNull() {
return reference == null;
}
@Override
public String toString() {
return "BackReference{" +
"reference=" + reference +
'}';
}
}