Creating Methods for Input/Output Files

Basically, I had to find various properties of a cylinder and make separate methods to do each of these. This is no problem and that runs fine. But every time I try to make a method to do input and output I get several errors and it will not run.
So right now I just have the input and output files being read inside the main method , but i need separate methods for the input and output files.
I need help creating these methods for input/output.

Thank You

Here's the code I have:

Code Java:

---

import java.io.*;
import java.util.*;
import javax.swing.*;
 
public class Shapes {
 
    static Scanner input = new Scanner(System.in);
    public static void main(String[] args) throws FileNotFoundException {
	Scanner inFile = new Scanner (new FileReader("dimensions.txt"));
	PrintWriter output = new PrintWriter("C:\\Users\\user\\Desktop\\shapes.txt");
 
    double x = inFile.nextDouble();
	double y = inFile.nextDouble();
 
	double height, radius, base, lateral, surface, volume, outputs;
	radius = x;
	height = y;
 
	base = baseArea(radius);
	lateral = lateralArea(radius, height);
	surface = surfaceArea(lateral, base);
	volume = cylinderVolume(base, height);
 
// this is just to check the calculations without having to open the output evertime
	System.out.println(radius);
	System.out.println(height);
	System.out.println(base);
	System.out.println(lateral);
	System.out.println(surface);
	System.out.println(volume);
 
	output.println(base + "      " + lateral + "      " + surface + "      " + volume);
 
    input.close();
    output.close();
    }
 
// calculates the base area. "a" is the radius and "b" is the value for base area.
public static double baseArea(double a){
	double b = Math.PI * a * a;
	return b;
	}
 
public static double lateralArea(double r, double h){
	double cir = Math.PI * 2 * r;
	double lat = cir * h;
	return lat;
	}
 
public static double surfaceArea (double la, double ba){
	double sur = la + ba + ba;
	return sur;
	}
 
public static double cylinderVolume (double base, double h){
	double vol = base * h;
	return vol;
	}
 
}

---

What will be the content of dimensions.txt?

Oh I'm sorry. I just chose two values to test it:
4.5
2.5