static void zip2dir(File inZip, File/S outDir) {
  zip2dir(inZip, outDir, "");
}

static void zip2dir(File inZip, File/S outDir, S prefix) ctex {
  if (prefix.length() != 0 && !prefix.endsWith("/")) prefix += "/";
  
  temp ZipFile zipFile = new ZipFile(inZip);
  Enumeration entries = zipFile.entries();
  while (entries.hasMoreElements()) {
    ZipEntry entry = (ZipEntry) entries.nextElement(); 
    
    if (entry.isDirectory()) continue; // We care about files only, really. Directories are made on the fly anyway.
    
    if (!entry.getName().startsWith(prefix)) continue;
    
    File outFile = new File(outDir, entry.getName());
    print("Unzipping " + entry.getName() + " to " + outFile.getAbsolutePath());
    
    stream2file(zipFile.getInputStream(entry), outFile);
  }
}

Began life as a copy of #1001173