source: doc/theses/jiada_liang_MMath/testP2.java @ db19e1d

import java.io.*;

public class testP2 {
        public enum Planet {
                //          mass      radius
                MERCURY ( 3.303e+23, 2.4397e6 ),
                VENUS   ( 4.869e+24, 6.0518e6 ),
                EARTH   ( 5.976e+24, 6.37814e6 ),
                MARS    ( 6.421e+23, 3.3972e6 ),
                JUPITER ( 1.9e+27,   7.1492e7 ),
                SATURN  ( 5.688e+26, 6.0268e7 ),
                URANUS  ( 8.686e+25, 2.5559e7 ),
                NEPTUNE ( 1.024e+26, 2.4746e7 );

                private final double mass;   // in kilograms
                public final double radius; // in meters

                Planet( double mass, double radius ) {
                        this.mass = mass; this.radius = radius;
                }
        }
        static double mass( Planet p ) { return p.mass; }
        static double radius( Planet p ) { return p.radius; }

        static double surfaceGravity( Planet p ) {
                return 6.67300E-11 * p.mass / ( p.radius * p.radius );
        }
        static double surfaceWeight( Planet p, double otherMass ) {
                return otherMass * surfaceGravity( p );
        }
        public static void main( String[] args ) {
                if ( args.length != 1 ) {
                        System.err.println( "Usage: java Planet <earth_weight>" );
                        System.exit( -1 );
                }
                Planet day = Planet.valueOf( "EARTH" );
                System.out.println( day.ordinal() + " " + day.name() + " " + day.mass + " " + day.radius + " " + Planet.valueOf( "EARTH" ) ); // 5 Sat

                double earthWeight = Double.parseDouble( args[0] );
                double mass = earthWeight / surfaceGravity( Planet.EARTH );
                for ( Planet p : Planet.values() )
                        System.out.printf( "Your weight on %s is %f%n", p, surfaceWeight( p, mass ) );
        }
}

// java test