java中的密码保护zip文件

Question

import java.io.*;
import java.util.zip.*;

public class ZipCreateExample {
  public static void main(String[] args) throws IOException {
    System.out.print("Please enter file name to zip : ");
    BufferedReader input = new BufferedReader
        (new InputStreamReader(System.in));
    String filesToZip = input.readLine();
    File f = new File(filesToZip);
    if(!f.exists()) {
      System.out.println("File not found.");
      System.exit(0);
    }
    System.out.print("Please enter zip file name : ");
    String zipFileName = input.readLine();
    if (!zipFileName.endsWith(".zip"))
      zipFileName = zipFileName + ".zip";
    byte[] buffer = new byte[18024];
    try {
      ZipOutputStream out = new ZipOutputStream
          (new FileOutputStream(zipFileName));
      out.setLevel(Deflater.DEFAULT_COMPRESSION);
      FileInputStream in = new FileInputStream(filesToZip);
      out.putNextEntry(new ZipEntry(filesToZip));
      int len;
      while ((len = in.read(buffer)) > 0) {
        out.write(buffer, 0, len);
      }
      out.closeEntry();
      in.close();
      out.close();
    } catch (IllegalArgumentException iae) {
      iae.printStackTrace();
      System.exit(0);
    } catch (FileNotFoundException fnfe) {
      fnfe.printStackTrace();
      System.exit(0);
    } catch (IOException ioe) {
      ioe.printStackTrace();
      System.exit(0);
    }
  }
}