package com.atlassian.plugin.util.zip;
   
   import org.apache.commons.io.IOUtils;
   import org.apache.commons.lang3.StringUtils;
   
   import java.io.File;
   import java.io.IOException;
   import java.io.InputStream;
   import java.util.zip.ZipEntry;
  import java.util.zip.ZipInputStream;
  
  /**
   * Stream based ZIP extractor
   */
  public class StreamUnzipper extends AbstractUnzipper {
      private ZipInputStream zis;
  
      /**
       * Construct a stream unzipper
       *
       * @param zipStream Inputstream to use for ZIP archive reading
       * @param destDir   Directory to unpack stream contents
       */
      public StreamUnzipper(InputStream zipStream, File destDir) {
          if (zipStream == null)
              throw new IllegalArgumentException("zip stream cannot be null");
          this.zis = new ZipInputStream(zipStream);
          this.destDir = destDir;
      }
  
      public void unzip() throws IOException {
          ZipEntry zipEntry = zis.getNextEntry();
          try {
              while (zipEntry != null) {
                  saveEntry(zis, zipEntry);
                  zis.closeEntry();
                  zipEntry = zis.getNextEntry();
              }
          } finally {
              IOUtils.closeQuietly(zis);
          }
      }
  
      public File unzipFileInArchive(String fileName) throws IOException {
          File result = null;
  
          try {
              ZipEntry zipEntry = zis.getNextEntry();
              while (zipEntry != null) {
                  String entryName = zipEntry.getName();
  
                  // os-dependent zips contain a leading back slash "\" character. we want to strip this off first
                  if (StringUtils.isNotEmpty(entryName) && entryName.startsWith("/"))
                      entryName = entryName.substring(1);
  
                  if (fileName.equals(entryName)) {
                      result = saveEntry(zis, zipEntry);
                      break;
                  }
                  zis.closeEntry();
                  zipEntry = zis.getNextEntry();
              }
          } finally {
              IOUtils.closeQuietly(zis);
          }
  
          return result;
      }
  
      public ZipEntry[] entries() throws IOException {
          return entries(zis);
      }
  }