Annotations/src/dorkbox/annotation/ZipFileIterator.java

114 lines
3.6 KiB
Java

/* ZipFileIterator.java
*
* Created: 2011-10-10 (Year-Month-Day)
* Character encoding: UTF-8
*
****************************************** LICENSE *******************************************
*
* Copyright (c) 2011 - 2013 XIAM Solutions B.V. (http://www.xiam.nl)
* Copyright 2014 dorkbox, llc
*
* Licensed 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 dorkbox.annotation;
import java.io.File;
import java.io.FilenameFilter;
import java.io.IOException;
import java.io.InputStream;
import java.util.Enumeration;
import java.util.zip.ZipEntry;
import java.util.zip.ZipFile;
/**
* {@code ZipFileIterator} is used to iterate over all entries in a given {@code zip} or
* {@code jar} file and returning the {@link InputStream} of these entries.
* <p/>
* It is possible to specify an (optional) entry name filter.
* <p/>
* The most efficient way of iterating is used, see benchmark in test classes.
*
* @author <a href="mailto:rmuller@xiam.nl">Ronald K. Muller</a>
* @since annotation-detector 3.0.0
*
* @author dorkbox, llc
*/
final
class ZipFileIterator {
private final File file;
private final ZipFile zipFile;
private final String[] entryNameFilter;
private final Enumeration<? extends ZipEntry> entries;
private ZipEntry current;
/**
* Create a new {@code ZipFileIterator} instance.
*
* @param file The ZIP file used to iterate over all entries
* @param entryNameFilter (optional) file name filter. Only entry names starting with
* one of the specified names in the filter are returned
*/
ZipFileIterator(final File file, final String[] entryNameFilter) throws IOException {
this.file = file;
this.zipFile = new ZipFile(file);
this.entryNameFilter = entryNameFilter;
this.entries = this.zipFile.entries();
}
public
ZipEntry getEntry() {
return this.current;
}
public
InputStream next(final FilenameFilter filter) throws IOException {
while (this.entries.hasMoreElements()) {
this.current = this.entries.nextElement();
if (filter == null || accept(this.current, filter)) {
return this.zipFile.getInputStream(this.current);
}
}
// no more entries in this ZipFile, so close ZipFile
try {
// zipFile is never null here
this.zipFile.close();
} catch (IOException ex) {
// suppress IOException, otherwise close() is called twice
}
return null;
}
private
boolean accept(final ZipEntry entry, final FilenameFilter filter) {
if (entry.isDirectory()) {
return false;
}
final String name = entry.getName();
if (name.endsWith(".class") && filter.accept(this.file, name)) {
if (this.entryNameFilter == null) {
return true;
}
for (final String entryName : this.entryNameFilter) {
if (name.startsWith(entryName)) {
return true;
}
}
}
return false;
}
}