/*
* Copyright © 2014 Cask Data, Inc.
*
* 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.
*/
package co.cask.cdap.common.lang.jar;
import java.io.File;
import java.util.Enumeration;
import java.util.LinkedList;
import java.util.Queue;
/**
* Like JarInputStream, but for an unpacked jar directory instead of a jar file.
*/
public class UnpackedJarDirIterator implements Enumeration<UnpackedJarDirEntry> {
private final File bundleJarDir;
private final Queue<File> fileQueue = new LinkedList<>();
private File nextFile;
public UnpackedJarDirIterator(File bundleJarDir) {
this.bundleJarDir = bundleJarDir;
fileQueue.add(bundleJarDir);
nextFile = seekToNextFile();
}
@Override
public boolean hasMoreElements() {
return nextFile != null;
}
@Override
public UnpackedJarDirEntry nextElement() {
File result = nextFile;
nextFile = seekToNextFile();
return new UnpackedJarDirEntry(bundleJarDir, result);
}
public void close() {
fileQueue.clear();
}
private File seekToNextFile() {
File currFile;
do {
currFile = fileQueue.poll();
if (currFile != null && currFile.isDirectory()) {
File[] children = currFile.listFiles();
if (children != null) {
for (File file : children) {
fileQueue.add(file);
}
}
}
} while (!fileQueue.isEmpty() && currFile != null && currFile.isDirectory());
return currFile;
}
}