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125 lines
4.7 KiB
Java
125 lines
4.7 KiB
Java
// enumerateFiles.java
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// -------------------------------------
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// (C) by Michael Peter Christen; mc@yacy.net
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// first published on http://www.anomic.de
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// Frankfurt, Germany, 2004
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//
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// $LastChangedDate$
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// $LastChangedRevision$
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// $LastChangedBy$
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//
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// This program is free software; you can redistribute it and/or modify
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// it under the terms of the GNU General Public License as published by
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// the Free Software Foundation; either version 2 of the License, or
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// (at your option) any later version.
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//
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// This program is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU General Public License for more details.
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//
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// You should have received a copy of the GNU General Public License
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// along with this program; if not, write to the Free Software
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// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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package net.yacy.utils;
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import java.io.File;
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import java.util.ArrayList;
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import java.util.Enumeration;
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import java.util.List;
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import java.util.TreeSet;
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import net.yacy.kelondro.util.FileUtils;
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public class enumerateFiles implements Enumeration<File> {
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// implements iterative search through recursively defined subdirectories
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// and return all paths to the files
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private final List<TreeSet<File>> hierarchy; // contains TreeSet elements, each TreeSet contains File Entries
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private final boolean incOrder; // if true, the smallest value is returned first
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private File buffer; // the prefetch-buffer
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private final boolean return_files;
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private final boolean return_folders;
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private final boolean delete_emptyFolders;
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public enumerateFiles(final File root, final boolean files, final boolean folders, final boolean increasing, final boolean deleteEmptyFolders) {
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// we define our data structures first
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this.return_files = files;
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this.return_folders = folders;
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this.delete_emptyFolders = deleteEmptyFolders;
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this.hierarchy = new ArrayList<TreeSet<File>>();
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this.incOrder = increasing;
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// the we initially fill the hierarchy with the content of the root folder
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final TreeSet<File> t = new TreeSet<File>();
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final String[] l = root.list();
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// System.out.println("D " + l.toString());
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if (l != null) for (int i = 0; i < l.length; i++) t.add(new File(root, l[i]));
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this.hierarchy.add(t);
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// start with search by filling the buffer
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this.buffer = nextElement0();
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}
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private File nextElement0() {
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// the object is a File pointing to the corresponding file
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File f;
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TreeSet<File> t;
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do {
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// System.out.println("D " + hierarchy.toString());
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t = null;
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while ((t == null) && (!hierarchy.isEmpty())) {
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t = hierarchy.get(hierarchy.size() - 1);
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if (t.isEmpty()) {
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hierarchy.remove(hierarchy.size() - 1); // we step up one hierarchy
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t = null;
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}
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}
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if (hierarchy.isEmpty() || (t == null || t.isEmpty())) return null; // this is the end
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// fetch value
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if (incOrder) f = t.first(); else f = t.last();
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t.remove(f);
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// if the value represents another folder, we step into the next hierarchy
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if (f.isDirectory()) {
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t = new TreeSet<File>();
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final String[] l = f.list();
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if (l == null) {
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// f has disappeared
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f = null;
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} else {
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if (l.length == 0) {
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if (delete_emptyFolders) {
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FileUtils.deletedelete(f);
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f = null;
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} else {
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if (!(return_folders)) f = null;
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}
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} else {
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for (int i = 0; i < l.length; i++) t.add(new File(f, l[i]));
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hierarchy.add(t);
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if (!(return_folders)) f = null;
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}
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}
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} else {
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if (!(return_files)) f = null;
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}
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} while (f == null);
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// thats it
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return f;
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}
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@Override
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public boolean hasMoreElements() {
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return buffer != null;
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}
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@Override
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public File nextElement() {
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final File r = buffer;
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buffer = nextElement0();
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return r;
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}
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}
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