Seite 11: Listing 7

Inhaltsverzeichnis

Listing 7: Konstruktor und main-Methode der Anwendungsklasse CFileCrypter

package net.nieden.FileCrypter;

import java.io.*;
import java.util.*;
import javax.crypto.*;
import javax.swing.JOptionPane;

public class CFileCrypter implements IFileProgressIndicator {
    final static int OPT_BUFSZ_FLS=0, OPT_COMPRESS=1, OPT_DECRYPTION=2, 
       OPT_ENCRYPTION=3, OPT_LIST=4, OPT_MULTITHREAD=5,
           OPT_PASSWD_FLS=6, OPT_REMOVE=7, OPT_STOREPWD=8, OPT_VERBOSE=9,
               DEFAULT_BUFSZ_KB=1024, MAX_BUFSZ_KB=32*1024;
    int opCount=0;
    BitSet bsOption=new BitSet();
    String passWord="", options="bcdelmprsv";
    ArrayList<File> fileList=new ArrayList<File>();
    long timerStart;
    int    bufSizeKB=DEFAULT_BUFSZ_KB;

    public CFileCrypter(String[] args) throws Exception {
        for (String s: args) {
            if (s.startsWith("-")&&s.length() > 1) {
                boolean b=false;
                for (int i=1;i<s.length();i++) {
                    int idx=options.indexOf(s.charAt(i));
                    if (idx < 0) usage(true);
                    switch(idx) {
                    case OPT_BUFSZ_FLS:
                        if ((i+1)<s.length()) {
                            bufSizeKB=Integer.parseInt(s.substring(i+1));
                        } else bsOption.set(idx);
                        b=true;    break;
                    case OPT_PASSWD_FLS:
                        if ((i+1)<s.length()) {
                            passWord=s.substring(i+1);
                        } else bsOption.set(idx);
                        b=true;    break;
                    default: bsOption.set(idx);
                        break;
                    }
                    if (b) break;
                }
                continue;
            }
            if (bsOption.get(OPT_BUFSZ_FLS)) {
                bufSizeKB=Integer.parseInt(s);
                bsOption.clear(OPT_BUFSZ_FLS);
            } else if (bsOption.get(OPT_PASSWD_FLS)) {
                passWord=s;    bsOption.clear(OPT_PASSWD_FLS);
            } else {
                File f=new File(s);
                if (!f.isFile()) throw new Exception(s+" is not 
                    a valid filename!");
                fileList.add(f);
            }
        }
        /**
         * Check parameters
         */
        if (bsOption.get(OPT_ENCRYPTION)) opCount++;
        if (bsOption.get(OPT_DECRYPTION)) opCount++;
        if (bsOption.get(OPT_LIST)) opCount++;
        if (opCount!=1) {
            usage("Must specify exactly e(ncryption), d(ecryption) 
                or l(ist) ...", true);
        }
        if (bufSizeKB < 1 || bufSizeKB>MAX_BUFSZ_KB) {
            usage("Illegal BufferSize in KB specified 
                (Must be >= 1 <= "+MAX_BUFSZ_KB, true);
        }
        if (fileList.isEmpty()) {
            usage("Must specify at least one valid file!", true);
        }
        if (passWord.isEmpty()) {
            /**
             * prompt for a password right now
             */
            CPasswdReader cpReader = new CPasswdReader();
            String s=cpReader.readPasswd();
            if (s==null  || s.isEmpty()) {
                JOptionPane.showMessageDialog(null, "Empty password 
                    - exiting","Error",JOptionPane.ERROR_MESSAGE);
                System.exit(1);
            }
        }
        if (bufSizeKB!=DEFAULT_BUFSZ_KB && bsOption.get(OPT_VERBOSE))
            System.out.printf("Setting buffer Size to %d KB\n", bufSizeKB);
    }

    public void processFileList() throws Exception {
...
    }

    public void usage() {
        usage(null, false);
    }

    public void usage(boolean isExit) {
        usage(null, isExit);
    }

    public void usage(String s) {
        usage(s, false);
    }

    public void usage(String s, boolean isExit) {
        if (s!=null) System.err.println(s);
        System.err.println("usage: java "+CFileCrypter.class.getName()+" 
            -options file ...");
        System.err.println("valid options are:");
        System.err.println("\t-b Blocksize in KB [1-32.768]");
        System.err.println("\t-c = compress (GZIP) before encryption");
        System.err.println("\t-d = decrpyt");
        System.err.println("\t-e = encrypt");
        System.err.println("\t-l = list original file data");
        System.err.println("\t-m = use multithread mechanism");
        System.err.println("\t-p password (En-/Decryption salt key)");
        System.err.println("\t-r = remove Source File after processing");
        System.err.println("\t-s = store password (not recommended)");
        System.err.println("\t-v = verbose operation");
        if (isExit) System.exit(1);
    }

    public boolean progressIndicator(int num, int max) {
        return true;
    }

    public static void main(String[] args) {
        try {
            if (args.length == 0) {
                new CFileCrypterGUI();
            } else {
                CFileCrypter cc=new CFileCrypter(args);
                cc.processFileList();
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}