org.apache.openjpa.lib.meta.FileMetaDataIterator Maven / Gradle / Ivy
/*
* 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.openjpa.lib.meta;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.net.MalformedURLException;
import java.net.URL;
import java.security.AccessController;
import java.security.PrivilegedActionException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Iterator;
import java.util.NoSuchElementException;
import org.apache.openjpa.lib.util.J2DoPrivHelper;
import org.apache.openjpa.lib.util.Localizer;
/**
* Iterator over a file, or over all metadata resources below a given directory.
*
* @author Abe White
*/
public class FileMetaDataIterator implements MetaDataIterator {
private static final long SCAN_LIMIT = 100000;
private static final Localizer _loc = Localizer.forPackage
(FileMetaDataIterator.class);
private final Iterator _itr;
private File _file = null;
/**
* Constructor; supply metadata file.
*/
public FileMetaDataIterator(File file) {
_itr = Collections.singleton(file).iterator();
}
/**
* Constructor; supply root of directory tree to search and optional
* file filter.
*/
public FileMetaDataIterator(File dir, MetaDataFilter filter)
throws IOException {
if (dir == null)
_itr = null;
else {
Collection metas = new ArrayList<>();
FileResource rsrc = (filter == null) ? null : new FileResource();
scan(dir, filter, rsrc, metas, 0);
_itr = metas.iterator();
}
}
/**
* Scan all files below the given one for metadata files, adding them
* to the given collection.
*/
private int scan(File file, MetaDataFilter filter, FileResource rsrc,
Collection metas, int scanned) throws IOException {
if (scanned > SCAN_LIMIT)
throw new IllegalStateException(_loc.get("too-many-files",
String.valueOf(SCAN_LIMIT)).getMessage());
scanned++;
if (filter == null)
metas.add(file);
else {
rsrc.setFile(file);
if (filter.matches(rsrc))
metas.add(file);
else {
File[] files = (File[]) AccessController
.doPrivileged(J2DoPrivHelper.listFilesAction(file));
if (files != null)
for (int i = 0; i < files.length; i++)
scanned = scan(files[i], filter, rsrc, metas, scanned);
}
}
return scanned;
}
@Override
public boolean hasNext() {
return _itr != null && _itr.hasNext();
}
@Override
public URL next() throws IOException {
if (_itr == null)
throw new NoSuchElementException();
_file = _itr.next();
try {
File f = AccessController.doPrivileged(J2DoPrivHelper
.getAbsoluteFileAction(_file));
return AccessController.doPrivileged(
J2DoPrivHelper.toURLAction(f));
} catch (PrivilegedActionException pae) {
throw (MalformedURLException) pae.getException();
}
}
@Override
public InputStream getInputStream() throws IOException {
if (_file == null)
throw new IllegalStateException();
FileInputStream fis = null;
try {
fis = AccessController.doPrivileged(
J2DoPrivHelper.newFileInputStreamAction(_file));
return fis;
} catch (PrivilegedActionException pae) {
throw (FileNotFoundException) pae.getException();
}
}
@Override
public File getFile() {
if (_file == null)
throw new IllegalStateException();
return _file;
}
@Override
public void close() {
}
private static class FileResource implements MetaDataFilter.Resource {
private File _file = null;
public void setFile(File file) {
_file = file;
}
@Override
public String getName() {
return _file.getName();
}
@Override
public byte[] getContent() throws IOException {
long len = (AccessController.doPrivileged(
J2DoPrivHelper.lengthAction(_file))).longValue();
FileInputStream fin = null;
try {
fin = AccessController.doPrivileged(
J2DoPrivHelper.newFileInputStreamAction(_file));
} catch (PrivilegedActionException pae) {
throw (FileNotFoundException) pae.getException();
}
try {
byte[] content;
if (len <= 0 || len > Integer.MAX_VALUE) {
// some JVMs don't return a proper length
ByteArrayOutputStream bout = new ByteArrayOutputStream();
byte[] buf = new byte[1024];
for (int r; (r = fin.read(buf)) != -1;)
bout.write(buf, 0, r);
content = bout.toByteArray();
} else {
content = new byte[(int) len];
for (int r, o = 0; o < content.length && (r = fin.
read(content, o, content.length - o)) != -1; o += r);
}
return content;
} finally {
try { fin.close(); } catch (IOException ioe) {}
}
}
}
}