Euler's Method for Estimating Differential Equations

EulersMethod.java

public class EulersMethod {
	
	private double x1;
	private double y1;
	private double dx;
	private double x2;
	private Differential dydx;
	
	public interface Differential {	
		double equation(double x, double y);
	}
	
	public EulersMethod(double x1, double y1, double dx, double x2, Differential dydx) {
		this.x1 = x1;
		this.y1 = y1;
		this.dx = dx;
		this.x2 = x2;
		this.dydx = dydx;
	}
	
	public double calculate() {
		double y = y1;
		for (double x = x1; x < x2; x += dx) {
			y += dydx.equation(x,y) * dx;
		}
		return y;
	}
	
	public static void main(String[] args) {
		System.out.println(new EulesMethod(0.0, 1.0, 0.1, 0.5, (x, y) ->  y + x * y).calculate());
	}
}