Java Programming

I'm trying to compile this code so i can test it out but i get this error

Angle.java:18: illegal start of expression
public Angle ( double a , int units )
^
1 error

This is my code so far.

public class Angle
{
  private double rads;
    {
       final static public int RADIANS = 0, Degrees = 1;
       public Angle ( double a , int units )
       if ( units == RADIANS) { setRadians(a); }
       else if ( units == DEGREES) { setDegrees(a); }
       else throw new RuntimeException( "Bad Units: " + units );
    }
  public double getRadians() { return radians; }
  public void setRadians( double rads ) { radians = rads; }
  public String toString() { return getRadians() + " Radians"; }
  public double getDegrees() { return radians * 57.29577951; }
  public void setDegrees( double degs ) { radians = degs * 0.0174532925; }
  public String toString() { return getDegrees() + " Degrees"; }
}

I know its more than likely a syntax thing that im messing up although i feel like it could easily be something much bigger, any help to get me past this would be greatly appreciated.