garydgregory commented on a change in pull request #171: URL: https://github.com/apache/commons-io/pull/171#discussion_r538464842
########## File path: src/main/java/org/apache/commons/io/input/QueueInputStream.java ########## @@ -0,0 +1,90 @@ +/* + * 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.commons.io.input; + +import org.apache.commons.io.output.QueueOutputStream; + +import java.io.InputStream; +import java.io.PipedInputStream; +import java.io.PipedOutputStream; +import java.util.Objects; +import java.util.concurrent.BlockingQueue; +import java.util.concurrent.LinkedBlockingQueue; + +/** + * Simple alternative to JDK {@link java.io.PipedInputStream}; queue input stream provides what's written in queue output stream. + * + * Example usage: + * <pre> + * QueueInputStream inputStream = new QueueInputStream(); + * QueueOutputStream outputStream = inputStream.newQueueOutputStream(); + * + * outputStream.write("hello world".getBytes(UTF_8)); + * inputStream.read(); + * </pre> + * + * Unlike JDK {@link PipedInputStream} and {@link PipedOutputStream}, queue input/output streams may be + * used safely in a single thread or multiple threads. Also, unlike JDK classes, no special meaning is + * attached to initial or current thread. Instances can be used longer after initial threads exited. + * + * Closing a {@code QueueInputStream} has no effect. The methods in this class can be called after + * the stream has been closed without generating an {@code IOException}. + * + * @see QueueOutputStream + * @since 2.9.0 + */ +public class QueueInputStream extends InputStream { + + private final BlockingQueue<Integer> queue; + + /** + * Create a {@link QueueInputStream} with no limit to internal buffer size + */ + public QueueInputStream() { + this(new LinkedBlockingQueue<>()); + } + + /** + * Create a {@link QueueInputStream} with given buffer + * + * @param queue backing queue for the stream + */ + public QueueInputStream(final BlockingQueue<Integer> queue) { + this.queue = Objects.requireNonNull(queue, "queue is required"); + } + + /** + * Create an QueueOutputStream connected to this. Writes to the output stream will be visible to this input stream. Review comment: `an QueueOutputStream` -> `an instance`. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org
