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yacy_search_server/source/de/anomic/tools/enumerateFiles.java

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// enumerateFiles.java
// -------------------------------------
// (C) by Michael Peter Christen; mc@anomic.de
// first published on http://www.anomic.de
// Frankfurt, Germany, 2004
// last major change: 26.12.2004
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
//
// Using this software in any meaning (reading, learning, copying, compiling,
// running) means that you agree that the Author(s) is (are) not responsible
// for cost, loss of data or any harm that may be caused directly or indirectly
// by usage of this softare or this documentation. The usage of this software
// is on your own risk. The installation and usage (starting/running) of this
// software may allow other people or application to access your computer and
// any attached devices and is highly dependent on the configuration of the
// software which must be done by the user of the software; the author(s) is
// (are) also not responsible for proper configuration and usage of the
// software, even if provoked by documentation provided together with
// the software.
//
// Any changes to this file according to the GPL as documented in the file
// gpl.txt aside this file in the shipment you received can be done to the
// lines that follows this copyright notice here, but changes must not be
// done inside the copyright notive above. A re-distribution must contain
// the intact and unchanged copyright notice.
// Contributions and changes to the program code must be marked as such.
package de.anomic.tools;
import java.io.File;
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.TreeSet;
public class enumerateFiles implements Enumeration {
// implements iterative search through recursively defined subdirectories
// and return all paths to the files
private ArrayList hierarchy; // contains TreeSet elements, each TreeSet contains File Entries
private boolean incOrder; // if true, the smallest value is returned first
private Object buffer; // the prefetch-buffer
private boolean return_files;
private boolean return_folders;
private boolean delete_emptyFolders;
public enumerateFiles(File root, boolean files, boolean folders, boolean increasing, boolean deleteEmptyFolders) {
// we define our data structures first
this.return_files = files;
this.return_folders = folders;
this.delete_emptyFolders = deleteEmptyFolders;
this.hierarchy = new ArrayList();
this.incOrder = increasing;
// the we initially fill the hierarchy with the content of the root folder
TreeSet t = new TreeSet();
String[] l = root.list();
// System.out.println("D " + l.toString());
for (int i = 0; i < l.length; i++) t.add(new File(root, l[i]));
this.hierarchy.add(t);
// start with search by filling the buffer
this.buffer = nextElement0();
}
private Object nextElement0() {
// the object is a File pointing to the corresponding file
File f;
TreeSet t;
do {
// System.out.println("D " + hierarchy.toString());
t = null;
while ((t == null) && (hierarchy.size() > 0)) {
t = (TreeSet) hierarchy.get(hierarchy.size() - 1);
if (t.size() == 0) {
hierarchy.remove(hierarchy.size() - 1); // we step up one hierarchy
t = null;
}
}
if ((hierarchy.size() == 0) || (t.size() == 0)) return null; // this is the end
// fetch value
if (incOrder) f = (File) t.first(); else f = (File) t.last();
t.remove(f);
// if the value represents another folder, we step into the next hierarchy
if (f.isDirectory()) {
t = new TreeSet();
String[] l = f.list();
if (l.length == 0) {
if (delete_emptyFolders) {
f.delete();
f = null;
} else {
if (!(return_folders)) f = null;
}
} else {
for (int i = 0; i < l.length; i++) t.add(new File(f, l[i]));
hierarchy.add(t);
if (!(return_folders)) f = null;
}
} else {
if (!(return_files)) f = null;
}
} while (f == null);
// thats it
return f;
}
public boolean hasMoreElements() {
return buffer != null;
}
public Object nextElement() {
Object r = buffer;
buffer = nextElement0();
return r;
}
}