org.apache.openjpa.lib.meta.JarFileURLMetaDataIterator 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.IOException;
import java.io.InputStream;
import java.net.JarURLConnection;
import java.net.URL;
import java.security.AccessController;
import java.security.PrivilegedActionException;
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.NoSuchElementException;
import java.util.jar.JarEntry;
import java.util.jar.JarFile;
import org.apache.openjpa.lib.util.J2DoPrivHelper;
/**
* Iterator over all metadata resources in a given resource addressed by a jar:file URL.
*
*/
public class JarFileURLMetaDataIterator implements MetaDataIterator, MetaDataFilter.Resource {
private final MetaDataFilter _filter;
private final JarFile _jarFile;
private final JarEntry _jarTargetEntry;
private int index = 0;
private JarEntry _last = null;
private final ArrayList _entryList = new ArrayList();
public JarFileURLMetaDataIterator(URL url, MetaDataFilter filter) throws IOException {
if (url == null) {
_jarFile = null;
_jarTargetEntry = null;
} else {
JarURLConnection jarURLConn = (JarURLConnection) url.openConnection();
jarURLConn.setDefaultUseCaches(false);
try {
_jarFile = AccessController.doPrivileged(J2DoPrivHelper.getJarFileAction(jarURLConn));
_jarTargetEntry = AccessController.doPrivileged(J2DoPrivHelper.getJarEntryAction(jarURLConn));
if (_jarTargetEntry.isDirectory()) {
Enumeration jarEntryEnum = _jarFile.entries();
while (jarEntryEnum.hasMoreElements()) {
JarEntry jarEntry = jarEntryEnum.nextElement();
if (jarEntry.getName().startsWith(_jarTargetEntry.getName())) {
_entryList.add(jarEntry);
}
}
} else {
_entryList.add(_jarTargetEntry);
}
} catch (PrivilegedActionException pae) {
throw (IOException) pae.getException();
}
}
_filter = filter;
}
/**
* Return whether there is another resource to iterate over.
*/
public boolean hasNext() throws IOException {
if (_entryList.size() <= index) {
return false;
}
// Search for next metadata file
while (index < _entryList.size()) {
if (_filter != null && !_filter.matches(this)) {
index++;
continue;
}
break;
}
return (index < _entryList.size());
}
/**
* Return the next metadata resource.
*/
public Object next() throws IOException {
if (!hasNext()) {
throw new NoSuchElementException();
}
String ret = _entryList.get(index).getName();
_last = _entryList.get(index);
index++;
return ret;
}
/**
* Return the last-iterated metadata resource content as a stream.
*/
public InputStream getInputStream() throws IOException {
if (_last == null)
throw new IllegalStateException();
return _jarFile.getInputStream(_last);
}
/**
* Return the last-iterated metadata resource content as a file, or null if not an extant file.
*/
public File getFile() throws IOException {
if (_last == null)
throw new IllegalStateException();
return null;
}
/**
* Close the resources used by this iterator.
*/
public void close() {
try {
if (_jarFile != null)
_jarFile.close();
} catch (IOException ioe) {
}
}
// ////////////////////////////////////////
// MetaDataFilter.Resource implementation
// ////////////////////////////////////////
/**
* The name of the resource.
*/
public String getName() {
if (index < _entryList.size()) {
return _entryList.get(index).getName();
} else {
return null;
}
}
/**
* Resource content.
*/
public byte[] getContent() throws IOException {
if (_entryList.size() <= index) {
return new byte[0];
}
long size = _entryList.get(index).getSize();
if (size == 0)
return new byte[0];
InputStream in = _jarFile.getInputStream(_entryList.get(index));
byte[] content;
if (size < 0) {
ByteArrayOutputStream bout = new ByteArrayOutputStream();
byte[] buf = new byte[1024];
for (int r; (r = in.read(buf)) != -1; bout.write(buf, 0, r))
;
content = bout.toByteArray();
} else {
content = new byte[(int) size];
int offset = 0;
int read;
while (offset < size && (read = in.read(content, offset, (int) size - offset)) != -1) {
offset += read;
}
}
in.close();
return content;
}
}