Copyright (c) 2005, 2018 IBM Corporation and others.
This program and the accompanying materials
are made available under the terms of the Eclipse Public License 2.0
which accompanies this distribution, and is available at
https://www.eclipse.org/legal/epl-2.0/
SPDX-License-Identifier: EPL-2.0
Contributors:
    IBM Corporation - initial API and implementation
    Rob Harrop - SpringSource Inc. (bug 253942)
/*******************************************************************************
 * Copyright (c) 2005, 2018 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *     Rob Harrop - SpringSource Inc. (bug 253942)
 *******************************************************************************/

package org.eclipse.osgi.storage.bundlefile;

import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.util.Enumeration;
import java.util.Iterator;
import java.util.zip.ZipEntry;
import java.util.zip.ZipFile;
import org.eclipse.osgi.internal.debug.Debug;
import org.eclipse.osgi.internal.messages.Msg;
import org.eclipse.osgi.storage.BundleInfo;
import org.eclipse.osgi.util.NLS;

A BundleFile that uses a ZipFile as it base file.
/**
 * A BundleFile that uses a ZipFile as it base file.
 */
public class ZipBundleFile extends CloseableBundleFile<ZipEntry> {

	
The zip file
/**
	 * The zip file
	 */
	volatile ZipFile zipFile;

	public ZipBundleFile(File basefile, BundleInfo.Generation generation, MRUBundleFileList mruList, Debug debug) throws IOException {
		super(basefile, generation, mruList, debug);
		if (!BundleFile.secureAction.exists(basefile))
			throw new IOException(NLS.bind(Msg.ADAPTER_FILEEXIST_EXCEPTION, basefile));
	}

	@Override
	protected void doOpen() throws IOException {
		zipFile = BundleFile.secureAction.getZipFile(this.basefile);
	}

	
Returns a ZipEntry for the bundle file. Must be called while holding the open lock.
This method does not ensure that the ZipFile is opened. Callers may need to call getZipfile() prior to calling this 
method.
Params:
path – the path to an entry
Returns:
a ZipEntry or null if the entry does not exist/**
	* Returns a ZipEntry for the bundle file. Must be called while holding the open lock.
	* This method does not ensure that the ZipFile is opened. Callers may need to call getZipfile() prior to calling this 
	* method.
	* @param path the path to an entry
	* @return a ZipEntry or null if the entry does not exist
	*/
	private ZipEntry getZipEntry(String path) {
		if (path.length() > 0 && path.charAt(0) == '/')
			path = path.substring(1);
		ZipEntry entry = zipFile.getEntry(path);
		if (entry != null && entry.getSize() == 0 && !entry.isDirectory()) {
			// work around the directory bug see bug 83542
			ZipEntry dirEntry = zipFile.getEntry(path + '/');
			if (dirEntry != null)
				entry = dirEntry;
		}
		return entry;
	}

	@Override
	protected BundleEntry findEntry(String path) {
		ZipEntry zipEntry = getZipEntry(path);
		if (zipEntry == null) {
			if (path.length() == 0 || path.charAt(path.length() - 1) == '/') {
				// this is a directory request lets see if any entries exist in this directory
				if (containsDir(path))
					return new DirZipBundleEntry(this, path);
			}
			return null;
		}
		return new ZipBundleEntry(zipEntry, this);
	}

	@Override
	protected void doClose() throws IOException {
		zipFile.close();
	}

	@Override
	protected void postClose() {
		zipFile = null;
	}

	@Override
	protected InputStream doGetInputStream(ZipEntry entry) throws IOException {
		return zipFile.getInputStream(entry);
	}

	@Override
	protected Iterable<String> getPaths() {
		return new Iterable<String>() {
			@Override
			public Iterator<String> iterator() {
				final Enumeration<? extends ZipEntry> entries = zipFile.entries();
				return new Iterator<String>() {
					@Override
					public boolean hasNext() {
						return entries.hasMoreElements();
					}

					@Override
					public String next() {
						ZipEntry entry = entries.nextElement();
						return entry.getName();
					}

					@Override
					public void remove() {
						throw new UnsupportedOperationException();
					}
				};
			}
		};
	}
}