Problems with scanner

Question

Hi I'm trying to do a make this simple program:
import java.util.Scanner;
public class quadrGlgApp
public static void main(String[] args)
double a, b, c;
Scanner scan = new Scanner(System.in);
a = scan.nextDouble();
b = scan.nextDouble();
c = scan.nextDouble();
GlgLoesen(a,b,c);
protected static void GlgLoesen(double a,double b,double c)
double x1, x2, D;
System.out.println("");
System.out.println(a+"(x^2)+"+b+"x+"+c+"=0");
if (a==0)
if (b==0)
if (c==0){
System.out.println("=> x kann jeden beliebigen Wert annehmen!");
}else
System.out.println("=> Es existiert keine Loesung fuer x!");
}else{
x1=-(c/b);
System.out.println("=> x="+x1);
}else{
D= ((b*b)-4*a*c);
if(D>0)
D= Math.sqrt(D);
x1=(-b+D)/2*a;
x2=(-b-D)/2*a;
System.out.println("=> x1="+x1);
System.out.println("=> x2="+x2);
}else{
if(D==0)
x1=-b/2*a;
System.out.println("=> x="+x1);
}else
System.out.println("=> Es existiert keine reelle Loesung!");
It's running, but if I try to write something in a, let`s take for example 2.0, this is the result:
2.0
Exception in thread "main" java.util.InputMismatchException
at java.util.Scanner.throwFor(Scanner.java:819)
at java.util.Scanner.next(Scanner.java:1431)
at java.util.Scanner.nextDouble(Scanner.java:2335)
at quadrGlgApp.main(quadrGlgApp.java:17)
Process completed.
What is wrong? Please help, me.
p.s.:please excuse my bad english

Answer 1

One thread's enough.
http://forum.java.sun.com/thread.jspa?threadID=773139