org.apache.openjpa.lib.meta.ZipStreamMetaDataIterator 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.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.util.NoSuchElementException;
import java.util.zip.ZipEntry;
import java.util.zip.ZipInputStream;
/**
* Iterator over all metadata resources in a given zip input stream.
*
* @author Abe White
*/
public class ZipStreamMetaDataIterator
implements MetaDataIterator, MetaDataFilter.Resource {
private final ZipInputStream _stream;
private final MetaDataFilter _filter;
private ZipEntry _entry = null;
private ZipEntry _last = null;
private byte[] _buf = null;
/**
* Constructor; supply zip stream and optional metadata filter.
*/
public ZipStreamMetaDataIterator(ZipInputStream stream,
MetaDataFilter filter) {
_stream = stream;
_filter = filter;
}
public boolean hasNext() throws IOException {
if (_stream == null)
return false;
if (_entry != null)
return true;
// close last rsrc
if (_buf == null && _last != null)
_stream.closeEntry();
_last = null;
_buf = null;
// search for next file
ZipEntry entry;
while (_entry == null && (entry = _stream.getNextEntry()) != null) {
_entry = entry;
if (_filter != null && !_filter.matches(this)) {
_entry = null;
_stream.closeEntry();
}
}
return _entry != null;
}
public String next() throws IOException {
if (!hasNext())
throw new NoSuchElementException();
String ret = _entry.getName();
_last = _entry;
_entry = null;
return ret;
}
public InputStream getInputStream() {
if (_last == null)
throw new IllegalStateException();
if (_buf != null)
return new ByteArrayInputStream(_buf);
return new NoCloseInputStream();
}
public File getFile() {
return null;
}
public void close() {
try {
_stream.close();
} catch (IOException ioe) {
}
}
//////////////////////////////////////////
// MetaDataFilter.Resource implementation
//////////////////////////////////////////
public String getName() {
return _entry.getName();
}
public byte[] getContent() throws IOException {
// buffer content so that future calls to getInputStream can read
// the same data
ByteArrayOutputStream bout = new ByteArrayOutputStream();
byte[] buf = new byte[1024];
for (int r; (r = _stream.read(buf)) != -1; bout.write(buf, 0, r)) ;
_buf = bout.toByteArray();
_stream.closeEntry();
return _buf;
}
/**
* Non-closing input stream used to make sure the underlying zip
* stream is not closed.
*/
private class NoCloseInputStream extends InputStream {
public int available() throws IOException {
return _stream.available();
}
public int read() throws IOException {
return _stream.read();
}
public int read(byte[] b, int off, int len) throws IOException {
return _stream.read(b, off, len);
}
public void close() {
}
}
}