org.eclipse.blockchain.ui/src/org/eclipse/blockchain/ui/util/UnzipUtility.java

/*******************************************************************************
 * Copyright (c) 2020 RBEI and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v. 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:
 *		Pavithra Krishna Reddy - Initial contribution and API
 *******************************************************************************/
package org.eclipse.blockchain.ui.util;

import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.zip.ZipEntry;
import java.util.zip.ZipInputStream;

/**
 * This utility extracts files and directories of a standard zip file to a
 * destination directory.
 */

public class UnzipUtility {

	/**
	 * Size of the buffer to read/write data
	 */
	private static final int BUFFER_SIZE = 4096;

	/**
	 * Extracts a zip file specified by the zipFilePath to a directory specified
	 * by destDirectory (will be created if does not exists)
	 *
	 * @param zipFilePath
	 * @param destDirectory
	 * @throws IOException
	 */
	public static void unzip(final String zipFilePath,
			final String destDirectory) throws IOException {
		File destDir = new File(destDirectory);
		if (!destDir.exists()) {
			destDir.mkdir();
		}
		ZipInputStream zipIn = new ZipInputStream(
				new FileInputStream(zipFilePath));
		ZipEntry entry = zipIn.getNextEntry();
		// iterates over entries in the zip file
		while (entry != null) {
			String filePath = destDirectory + File.separator + entry.getName();
			if (!entry.isDirectory()) {
				// if the entry is a file, extracts it
				extractFile(zipIn, filePath);
			} else {
				// if the entry is a directory, make the directory
				File dir = new File(filePath);
				dir.mkdir();
			}
			zipIn.closeEntry();
			entry = zipIn.getNextEntry();
		}
		zipIn.close();
	}

	/**
	 * Extracts a zip entry (file entry)
	 *
	 * @param zipIn
	 * @param filePath
	 * @throws IOException
	 */
	private static void extractFile(final ZipInputStream zipIn,
			final String filePath) throws IOException {
		BufferedOutputStream bos = new BufferedOutputStream(
				new FileOutputStream(filePath));
		byte[] bytesIn = new byte[BUFFER_SIZE];
		int read = 0;
		while ((read = zipIn.read(bytesIn)) != -1) {
			bos.write(bytesIn, 0, read);
		}
		bos.close();
	}
}