Thread: I have no idea where or how to start!!

Project: File Encryption


Problem Description:

Suppose an encrypted file was created using the encoding/decoding scheme . Each letter is substituted by some other letter according to a given mapping as shown below.
String letters = "abcdefghijklmnopqrstuvwxyz";
String enc = "kngcadsxbvfhjtiumylzqropwe


For example, every 'a' becomes a 'k' when encoding a text, and every 'k' becomes an 'a' when decoding. You will write a program, encode or decode a File, and then encodes or decodes the File using the mapping above. Capital letters are mapped the same way as the lower case letters above, but remain capitalized. For example, every 'A' becomes 'K' when encoding a file, and every 'K' becomes an 'A' when decoding. Numbers and other characters are not encoded and remain the same.

Write a program to read a file and encode the file to an encrypted file. And write a program to get an encrypted file and decode to original file. Your program should prompt the user to enter an input file name and an output file name

What should you do?
1. Ask for input file name/ output file name (encrypted file). The encrypt using above encode/decode.
2. Ask for encrypted file and decoded to original input file.


Need help with this, i have no idea where to begin. I ask for someone to start it off for me, i am very new to this. Any help is dearly appreciated.

i have no idea where to begin

This is baloney and a cop out. If you do not know how to write a class with a main() method, then you're not going to do well in this class, are probably failing it now, and most likely will ultimately fail it. Only you can fix that. There's nothing we can do.

Originally Posted by GregBrannon

This is baloney and a cop out. If you do not know how to write a class with a main() method, then you're not going to do well in this class, are probably failing it now, and most likely will ultimately fail it. Only you can fix that. There's nothing we can do.

It's an intro class. But thanks for all your enlightenement, oh wise one.

Greg and Norm are of the most helpful people on here. Think how many times they have read post like yours. No code, no flow chart, or any logical way they are thinking about solving the problem. I am sure it annoys them at times.

On that note, break it down into smaller problems but first make sure you understand your requirements. Try to explain your thought process clearly if you are not going to post code, and if you do post code, please comment each line to what you think is happening.

Different guy, just googled the problem because I was struggling. Really... I'm just not feeling the vibe somewhere when engineers have to come in and out-nerd someone who is just asking for help. Been there many times, never can dig it.

Honestly speaking, Java is a dying language and I only chose to take the Intro class for credit and a bit of experience. Our professor is a great guy just not so much as a teacher. I can honestly say I don't know squat about Java in the 6th week of class. And by not knowing squat, I mean I can't sling a single line of good Java code for the life of me. I should've read the teacher reviews so I would've known he was gonna hit the ground running, but it said INTRO. Yet funny enough I should still leave the class with a B. But I digress.

Anyway, this is a variation of what I ended up entering:

Map<Character, Character> encode = new HashMap<>();
Map<Character, Character> decode = new HashMap<>()

//
encode.put('A', 'g');
decode.put('g,', 'A');

Was it right? Nah. But it was something

I prefer you not hijack someone else's thread, but it's too hard to pull your post out and make it stand on it's own, so we'll go with it. And why the attitude about Java? That's just trollish behavior, but I'll ignore that for now and assume you to be asking a sincere question.

The "Intro to Java" stage does not usually allow the use of advanced features like maps. If there was no prohibition on the core Java classes that could be used, your solution might work, though I'd have to see more code to be sure. More typically, a String of 26 alpha characters or a character array out of order to provide the encrypt/decrypt key are used at the intro level, similar to what the OP had suggested in the first post.

hahahaha. Dude you are exactly what I thought you were. Right, I hijacked this thread and am trollish, because you were so helpful before.

OP is a classmate. Not very hard to deduct given he made his account his actual name. The project is done. You were of no help when it mattered. That's interesting about maps. oh well. Anyway I'm not the one with an attitude problem, but hey, some things don't get better with time.
best

PS: My attitude about Java is practical and shared by many. I'm not giving you the numbers or anything because that's just baloney and a cop out Go google it!

Good luck to you both!