Best way to get data from a text file and then put it in an array of Solids?

I am writing a program that uses inheritance and polymorphism to sort solids.

Here is my Solids class, which is the parent of Rectangular, Sphere, and Cube.

Code:

---

import java.text.DecimalFormat;

public abstract class Solid {

        private String solidName;
        DecimalFormat roundHundreth = new DecimalFormat("#.##");
       
        //constructor for setting name to a default value
        //preconditions:none
        //postconditions:sets solidName to undefined
        public Solid(){
                solidName = "undefined";
        }
       
        //method for setting name to method argument
        //preconditions: must enter a String argument
        //postconditions: will set solidName to name
        public void setName(String name){
                solidName = name;
        }
       
        //getter method for Solid name
        //preconditions: none
        //postconditions: will return solidName
        public String getName(){
                return solidName;
        }
       
       
        //abstract method declarations
        public abstract double volume();
       
        public abstract double surface();
       
        public abstract void display();
               
       
       
       
}

---

And here is what one of child classes look like.

Code:

---

public class Rectangular extends Solid {
       
        private double length;
        private double width;
        private double height;
       
        public Rectangular(){
                setName("undefined");
        }
       
        public Rectangular(double len, double wid, double hei){
               
                setName("Rectangular");
                length = len;
                width = wid;
                height = hei;
        }
       

        public double volume() {
                //method to return volume of a rectangular prism
                //preconditions: must use defined constructor while instantiating Rectangular
                //postconditions: computes and returns volume
               
                double vol = length*width*height;
                return vol;
        }

       
        public double surface() {
                //method to return surface area of a rectangular prism
                //preconditions: must use defined constructor while instantiating Rectangular
                //postconditions: computes and returns surface area
               
                double surfaceArea = 2*length*height + 2*height*width + 2*length*width;
                return surfaceArea;
        }

       
        public void display() {
                //method to display info on a rectangular prism
                //postconditions: none
                //postconditions: displays information related to a rectangular prism
               
                System.out.printf("Rectangular Prism -- Length: %s  Width: %s  Height: %s  Volume: %s  Surface Area: %s\n", roundHundreth.format(length), roundHundreth.format(width), roundHundreth.format(height), roundHundreth.format(volume()), roundHundreth.format(surface()));
               
        }
}

---

I am wondering what the most efficient way to sort this text into an object of their respective class. (S = Sphere, etc) I already have a way to do it, but I feel like it could be far more efficient. How would you go about it?

S 0.5
R 1.5 5.2 3.75
R 40.0 1.0 1.0
C 0.75
C 7.5
C 75.0
S 37.5
S 1.0
S 1.25
R 74.0 76.0 11.5
C 3.14
C 1.77

What I see of your code seems ok so far - though I would change the name display() to toString(). What part of the posted code is your concern?