Compiler error Please Help

Can someone please help me with this compiler error. java:28: operator * cannot be applied to int,java.lang.String
StateTaxDue = 0.03 * incomeValue - (600 * dependents);

The program is:
import java.io.*;
import javax.swing.JOptionPane;
public class StateTax
{
public static void main(String[] args) throws IOException
{
BufferedReader inData;
inData = new BufferedReader(new InputStreamReader(System.in));

//declaring Variables
String income, dependents;
int StateTaxDue;
int incomeValue = Integer.parseInt(income);
int dependentsValue = Integer.parseInt(dependents);

//user input
System.out.println("State Tax Computation");
income = JOptionPane.showInputDialog(null, "Taxpayers Income:");
dependents = JOptionPane.showInputDialog(null, "Number Of Dependents:");

//Conversions
StateTaxDue = 0.03 * incomeValue - (600 * dependents);

//output
JOptionPane.showMessageDialog(null, "State Tax Due:" + StateTaxDue);
System.exit(0);


}
}

At first, I don't see the error. Could it be that 0.03 should be written as .03 ?
But since you're working with 2 constants, you could declare them at the beginning of you class,
like this
protectedfinal int PERCENTAGE = .03;

This way, if your class should become quite large, you have an overview of all
constants at the beginning of the class.