CODEWITHSUNDEEP
javaandroidencryption
codeFreak
codeFreak

Reputation: 353

Writing encrypted strings from a string array into a file

I have made reference from this question and achieved success in setting up encryption. I am trying to however utilize this encryption on a string of array to write into a file. This is how I am setting my method up but I end up writing only one of the string array into the file.

String[] str = new String ["X: Adam", "Y: Barry", "z: Oliver"];  

File file = new File(Path + "/EncryptedFile.txt);

Calling method to write the string array into the file: Crypto.WriteEncrypteFile(str, file);

The method

Public void WriteEncrypteFile(String[] str, File file) {
  try { 
    BufferedWriter w = new BufferedWriter(new FileWriter(file)); 
    byte[] tmptxt = Array.toString(str).getbytes(Charset.forName(" UTF-8 "));  
    byte[] encTxt = cipher.doFinal(tmptxt);
    w.write(string.valueOf(encTxt)); 
    w.flush();
    w.close(); 
  } catch (Exception e){
    e.printStackTrace();
  }    

My questions is how can I write an encrypted string from my array into the file. Any pointers?

Upvotes: 1

Views: 569

Answers (2)

mhlz
mhlz

Reputation: 3557

You are just writing the String value of the array to the file (since you use Array.toString(str)). This will usually just be some representation of the reference. You have to either concatenate the values of the array or loop through it and encrypt/write every value individually.

Additionally, you shouldn't use a Writer to write content that does not consist of characters. Writers always try to encode the output which could potentially ruin your carefully set up bytes.

Just use a FileOutputStream and write the bytes with that:

try( FileOutputStream fos = new FileOutputStream(file) ) {
    for(String s : str) {
        byte[] tmptxt = s.getbytes(Charset.forName("UTF-8"));  
        byte[] encTxt = cipher.doFinal(tmptxt);
        w.write(encTxt);
    }
} catch(IOException e) {
    // print error or whatever
}

For reading you do the same thing but with a FileInputStream instead.

Upvotes: 2

m0skit0
m0skit0

Reputation: 25874

You can use Arrays.toString(), but this way you will need to parse it to read it. Alternatively you can also write the byte[] directly in the file using an OutputStream. There's no need to convert to a string unless you want a human (e.g. yourself) to read it.

Upvotes: 0

Related Questions