Help With Simple Encryption Code

Question

I'm making a Cipher for personal use and possible publish as freeware. Can someone help me figure out what I'm missing in my code and/or post possible fixes? Thanks!
P.S. If this code looks ametuer, it's because it is. I'm just a freshman in college :)
Encryption Class:
import java.util.*;
import javax.crypto.*;
import javax.crypto.spec.*;
import java.security.*;
public class EncryptionModule {
static final int keylength = 42;
private SecretKeySpec skeySpec;
public EncryptionModule(String key)
skeySpec = makeKey(key);
public SecretKeySpec makeKey(String keys)
SecretKeySpec skeySpec = null;
try {
byte [] keys_raw = keys.getBytes();
skeySpec = new SecretKeySpec(keys_raw, "Blowfish");
} catch(Exception e) {
e.printStackTrace();
return skeySpec;
public String EncryptionModule(String line)
byte[] encrypted = new byte[0];
try {
Cipher cipher = Cipher.getInstance("Blowfish");
cipher.init(Cipher.ENCRYPT_MODE, skeySpec);
encrypted = cipher.doFinal(line.getBytes());
} catch(Exception e) {
e.printStackTrace();
return new String(encrypted);
public String Decrypt(String line)
byte[] decrypted = new byte[0];
try {
Cipher cipher = Cipher.getInstance("Blowfish");
cipher.init(Cipher.DECRYPT_MODE,skeySpec);
decrypted = cipher.doFinal(line.getBytes());
} catch(Exception e) {
e.printStackTrace();
return new String(decrypted);
File IO Class:
import java.io.*;
import java.awt.*;
import java.util.*;
public class FileIO
BufferedReader inputFile;
String inputFileName;
BufferedWriter outputFile;
String outputFileName;
ArrayList dataList;
ArrayList breakLine;
EncryptionModule EncryptionModuleor;
* Constructor for objects of class IO.
public FileIO(String key)
dataList = new ArrayList();
breakLine = new ArrayList();
EncryptionModuleor = new EncryptionModule(key);
public void main(String[] args) throws IOException
dataList = new ArrayList();
breakLine = new ArrayList();
setInputFile();
* setInputFile - Displays a dialog box to select and open a file for input
* @return true if success, false otherwise
public boolean setInputFile() throws IOException
boolean fileOpened = true;
FileDialog myDB = new FileDialog(new Frame(),"Select a log file for INPUT");
myDB.setDirectory(".");
myDB.show();
inputFileName = myDB.getFile();
if (inputFileName==null){
fileOpened = false;
else {
try {
inputFile = new BufferedReader(new FileReader(myDB.getDirectory()+"\\"+inputFileName));
catch(FileNotFoundException e) {
fileOpened = false;
return fileOpened;
* setOutputFile - Displays a dialog box to select and open or create a file for output
* @return true if success, false otherwise
public boolean setOutputFile() throws IOException
boolean fileOpened = true;
FileDialog myDB = new FileDialog(new Frame(),"Select or create a file for OUTPUT");
myDB.setDirectory(".");
myDB.setMode(FileDialog.SAVE);
myDB.show();
outputFileName = myDB.getFile();
if (outputFileName==null){
fileOpened = false;
else{
try {
outputFile = new BufferedWriter(new FileWriter(myDB.getDirectory()+"\\"+outputFileName));
catch(FileNotFoundException e) {
fileOpened = false;
return fileOpened;
public void processData()throws IOException
dataList = new ArrayList();
if (!setInputFile()){
System.out.println("Cannot open selected input file: "+inputFileName);
return;
String line;
line = inputFile.readLine(); //Read a new line from the input file
EncryptionModuleor = new EncryptionModule(line);
line = inputFile.readLine();
while(line != null)
dataList.add(EncryptionModuleor.EncryptionModule(line));
line = inputFile.readLine(); //Read a new line from the input file
copyFile();
public void copyFile() throws IOException
if (!setOutputFile()){
System.out.println("Cannot open selected output file: "+outputFileName);
return;
for (int i=0; i<dataList.size(); i++){
outputFile.write((String)dataList.get(i));
if (i<dataList.size()-1){
outputFile.newLine();
outputFile.close();
}

Answer 1

You dont say what the problem is so one has to guess!
1) " return new String(encrypted);"
It is not realy safe to convert bytes to String this way. This must be close to the number 1 problem seen in this forum. Use something like Base64 or HEX encoding.
2) Don't just catch exceptions and print out stack traces!
If you intend to publish the encrytpion class then define an exception class specific to this problem (maybe more than one) and convert internal exceptions that you can't handle to this exception.
3) You ave not defined a mode or padding and are relying on the default. Make it explicit so there is no argument as to what mode and padding is being used.
4) For some reason you are breaking a file into lines and then encrypting each line. Why not just encrypt the whole file as bytes. Much easier, quicker, less code.
5) Rather than use a GUI to select the file why not make them command line parameters using the standard UNIX/DOS approach.