org.atmosphere.util.annotation.InputStreamIterator Maven / Gradle / Ivy
package org.atmosphere.util.annotation;/*
* Copyright 2015 Async-IO.org
*
* 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.Deque;
import java.util.LinkedList;
/**
* {@code FileIterator} enables iteration over all files in a directory and all
* its sub directories.
*
* Usage:
*
* FileIterator iter = new FileIterator(new File("./src"));
* File f;
* while ((f = iter.next()) != null) {
* // do something with f
* assert f == iter.getCurrent();
* }
*
*
* @author Ronald K. Muller
* @since annotation-detector 3.0.0
*/
public final class InputStreamIterator {
private final Deque stack = new LinkedList();
private int rootCount;
private InputStream current;
/**
* Create a new {@code FileIterator} using the specified 'filesOrDirectories' as root.
*
* If 'filesOrDirectories' contains a file, the iterator just returns that single file.
* If 'filesOrDirectories' contains a directory, all files in that directory
* and its sub directories are returned (depth first).
*
* @param filesOrDirectories Zero or more {@link java.io.File} objects, which are iterated
* in the specified order (depth first)
*/
public InputStreamIterator(final InputStream... filesOrDirectories) {
addReverse(filesOrDirectories);
rootCount = stack.size();
}
/**
* Return the next {@link java.io.File} object or {@code null} if no more files are
* available.
*
*/
public InputStream next() throws IOException {
if (stack.isEmpty()) {
current = null;
return null;
} else {
current = stack.removeLast();
return current;
}
}
/**
* Add the specified files in reverse order.
*/
private void addReverse(final InputStream[] files) {
for (int i = files.length - 1; i >=0; --i) {
stack.add(files[i]);
}
}
}