Writing output from one file to a newly created file

Question

Should've started by saying I'm completely new at coding, this is for a final exercise in class and that I have "hit a brick wall at warp 11" on this one.

Writing a program that will read an already created file, convert content to uppercase and then create a new file and write the uppercase content to it? Here are my class and main:

import java.io.*;
import java.util.*;

public class readfile{
private Formatter z;
private Scanner x;

public void openFile(){

    try{
        x = new Scanner(new File ("week8lowercaseinput.txt"));
    }
    catch(Exception e){     
        System.out.println("Couldn't find file");           
    }
}
public void readFile(){
    while(x.hasNext()){
        String a = x.next();            
        String d = a.toUpperCase();

        System.out.printf("%s ", d);

    }
}
public void createFile(){

    try{
        z = new Formatter( new File ("WEEK8UPPERCASEOUTPUT.txt"));          
    }

    catch(Exception e){
        System.out.println("Couldn't create file.");
    }
    //z.Format("%s ", d);

}

public void closeFile(){
    x.close();
    //z.close();
}   
}

Main Class

import java.io.*;
import java.util.*;
import java.lang.*;

class TestReadFile{

public static void main(String[] args){

    readfile a = new readfile();
    a.openFile();
    a.readFile();       
    a.createFile();
    a.closeFile();

}

}

I'm able to open, read and convert content. I'm able to create a new file. The only thing that does not work is writing the converted content (uppercase) to new file. Any help would be greatly appreciated. Thank you.

In method createFile before creating Formatter call method f.createNewFile(); on creatted File instance — gauee, Dec 08 '15 at 23:37
Can you post the code that you actually used? You have local strings which you read and convert. — ChiefTwoPencils, Dec 08 '15 at 23:37
I see no attempt to write anything to the output file - ever... Not to mention "bad design" you open one file, create another, then `a.closeFile()` - which one is that supposed to close? just one? (which one?) both? — John3136, Dec 08 '15 at 23:42

score 0 · Answer 1 · answered Dec 09 '15 at 00:34

When you read from the file, you're just writing to the screen. You actually need to store the lines in some sort of data structure -- I'd recommend a List.

List<String> upperCaseLines = new ArrayList<>();

// inside readFile() while loop:
String line = x.next();
String uppercase = line.toUpperCase();
upperCaseLines.add(uppercase);

Then all you need to do is write the lines to file:

for(String line : upperCaseLines) {
    // write line to file
}

Also you'll want to rename your variables to things that make sense (what is x?) and your class name should start with a capital letter.

Frankly a better design would be to open both files, and write to the output file as you read from the input file.

Writing output from one file to a newly created file

1 Answers1