ZipJarUtil.java

/*
 * Copyright 2007-2009 Medsea Business Solutions S.L.
 *
 * 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 eu.medsea.util;

import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.net.JarURLConnection;
import java.net.URL;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Enumeration;
import java.util.zip.ZipEntry;
import java.util.zip.ZipException;
import java.util.zip.ZipFile;

 /**
  * Utility class providing methods to work with Zip and Jar Files
  * @author Steven McArdle
  *
  */
public class ZipJarUtil {

	/**
	 * Get an InputStream from the zip file capable of reading from
	 * @param url
	 * @return InputStream for reading from a jar or zip file
	 * @throws IOException
	 */
	public static InputStream getInputStreamForURL(URL url) throws IOException {
		JarURLConnection conn = (JarURLConnection)url.openConnection();
		return conn.getInputStream();
	}

	/**
	 * Get all entries from a Zip or Jar file. This defers to the getEntries(ZipFile zipFile) method
	 *
	 * Example of usage:
	 * Collection entries = ZipJarUtil.getEntries("src/test/resources/a.zip");
	 *
	 * @param fileName path identifying a zip or jar file
	 * @return collection of Strings representing the entries in the zip or jar file
	 * @throws ZipException
	 * @throws IOException
	 */
	public static Collection getEntries(String fileName) throws ZipException, IOException {
		return getEntries(new ZipFile(fileName));
	}

	/**
	 * Get all entries from a Zip or Jar file. This defers to the getEntries(ZipFile zipFile) method
	 *
	 * Example of usage:
	 * Collection entries = ZipJarUtil.getEntries(new File("src/test/resources/a.zip"));
	 *
	 * @param file identifies a zip or jar file
	 * @return collection of Strings representing the entries in the zip or jar file
	 * @throws ZipException
	 * @throws IOException
	 */
	public static Collection getEntries(File file) throws ZipException, IOException {
		return getEntries(new ZipFile(file));
	}

	/**
	 * Get all entries from a Zip or Jar file identified by a URL.
	 *
	 * Example of usage:
	 * Collection entries = ZipJarUtil.getEntries(new URL("jar:file:src/test/resources/a.zip!/"));
	 *
	 * This defers to the getEntries(ZipFile zipFile) method
	 *
	 * @param url identifying a jar or zip file. Can also refer to an entry, which is ignored.
	 * @return collection of Strings representing the entries in the zip or jar file
	 * @throws ZipException
	 * @throws IOException
	 */
	public static Collection getEntries(URL url) throws ZipException, IOException {
		JarURLConnection conn = (JarURLConnection)url.openConnection();
		return getEntries(conn.getJarFile());
	}

	/**
	 * Get all entries from a zip or jar file. Ignores directories
	 *
	 * @param zipFile
	 * @return collection of Strings representing the entries in the zip or jar file
	 * @throws ZipException
	 * @throws IOException
	 */
	public static Collection getEntries(ZipFile zipFile) throws ZipException, IOException {
		Collection entries = new ArrayList();

		Enumeration e = zipFile.entries();
		while(e.hasMoreElements()) {
			ZipEntry ze = (ZipEntry)e.nextElement();
			// We don't want directory entries
			if(!ze.isDirectory()) {
				entries.add(ze.getName());
			}
		}

		return entries;
	}

	public static void main(String [] args) throws Exception{

		System.out.println(ZipJarUtil.getEntries("src/test/resources/a.zip"));
		System.out.println(ZipJarUtil.getEntries(new File("src/test/resources/a.zip")));
		System.out.println(ZipJarUtil.getEntries(new URL("jar:file:src/test/resources/a.zip!/")));
		// This will ignore the entry part at the end of the URL and get all entries anyway
		System.out.println(ZipJarUtil.getEntries(new URL("jar:file:src/test/resources/a.zip!/resources/eu/medsea/mimeutil/magic.mime")));
	}
}