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

/*
 * Copyright (c) Robert Bosch GmbH. All rights reserved.
 */
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.
 *
 * @author PKI8COB
 */

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();
  }
}