CODEWITHSUNDEEP
javafile-ioinput
family2dyl
family2dyl

Reputation: 43

Saving multiple user inputs to a text file

Firstly I must apologize if this has already been explained... While I have done searches to find an answer to my problem, I am still very new when it comes to Java so I couldn't really understand. (I've only been learning Java for a couple of days.)

My friend, who is trying to teach me Java sets me assignments that I have to complete and I'm supposed to learn what I need to do to complete these assignments myself. Recently he gave me the challenge of creating a program that asks the user for their name, age and a username. This program then needs to output these in a sentence. That part is easy. What I'm having difficulty with is the next part where I have to make the program save these to a file, along with any future inputs from a user.

Here's what I have:

import java.util.Scanner;

public class easy1 
{

@SuppressWarnings("resource")
public static void main(String[] args)
{
    System.out.println("Enter your name, age and username: ");
    Scanner sc = new Scanner(System.in);

    String name = sc.next(), age = sc.next(), user = sc.next();

    System.out.println("Your name is " + name + ", you are " + age + " years old, and your username is " + user + ".");
}
}

I'm not really looking for anybody to tell me what to do, what I would appreciate is just a little guidance or a clue as to what I should be doing. If you do give me an answer then an explanation of how it works would be nice.

Thank you.

Upvotes: 4

Views: 25069

Answers (4)

Paul Vargas
Paul Vargas

Reputation: 42030

The simplest way is:

try (
    PrintWriter out = new PrintWriter("output.txt", "UTF-8");
    Scanner sc = new Scanner(System.in);
) {

    // Read input using sc

    // Output to out, e.g.
    out.println("Your name is " + name + ".");

} catch(IOException e) {
    // Manage the exception
}

Upvotes: 1

Ray Stojonic
Ray Stojonic

Reputation: 1270

You'll need to open an output file and write to it.

Probably the easiest way to do this is to use a PrintStream, which you'll be familiar with using as System.out is a PrintStream.

Assuming you're using Java 7:

try( PrintStream out = new PrintStream( new File( "output.txt" ) ) ) {
    out.println( stuff );
}

By using the try-with-resources block, the PrintStream and File are automatically closed for you after you're done writing. edit: and you'll already have the try in place to handle the FileNotFoundException that PrintStream( File ) says it may throw.

Upvotes: 2

Paul Samsotha
Paul Samsotha

Reputation: 209004

To save to file you need to create a File object.

File file = new File("someFile.txt");   -- takes file name as argument.

Then you need a way to print to the file. You can use PrintWriter

PrintWriter writer = new PrintWriter(file);  -- takes file as argument.

To write to the file, just use the PrintWriter write() method

writer.write(name);

If you're only in your second day of learning, tell your friend it's too early to be learning about I/O (input/output). You should be learning about loops, arrays, methods, operators, if/else if statements, Strings, etc. All the basics. Once you've finished the basics, you're ready to get into Object Oriented Programming (OOP). That's where the real magic happens. So take time to learn the basics, so you'll be ready for the deeper stuff.

Pick up a comprehensive book. I'd recommend a textbook Introduction to Java Programming by Daniel liang

Upvotes: 5

MadConan
MadConan

Reputation: 3767

You need to tap into java.io.File and java.io.FileOutputStream (or java.io.FileWriter). Start here. It will look something like this (*this is not complete -- you'll need exception handling! *)

String input = getInput();
BufferedWriter writer = new BufferedWriter(new FileWriter(new File("myFile")));
writer.write(input,0,input.length());
writer.close();

I can't say this enough: Read the API :)

Upvotes: 2

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