java - How to utilize a switch statement in this instance? -

i'm writing program converts units (ex. oz & lb) new units of measurement (g & kg). going have user input unit want convert , value of original unit. set constants convert selected units. i'm having issue using switch statement determine conversion should use (oz ---> g, oz --->, etc).

here's code:

    system.out.print("convert from: ");     string origmeasure = input.nextline();      system.out.print("convert to: ");     string newmeasure = input.nextline();      system.out.print("value: ");     double value = input.nextdouble();      double newvalue = 0;      final double oz_to_g = 28.3;     final double oz_to_kg = 0.028;     final double lb_to_g = 453.6;     final double lb_to_kg = 0.045;     final double in_to_mm = 25.4;     final double in_to_cm = 2.54;     final double in_to_m = 0.0254;     final double ft_to_mm = 304.8;     final double ft_to_cm = 30.48;     final double ft_to_m = 0.3048;      final string oz = " oz";     final string lb = " lb";     final string in = " in";     final string ft = " ft";     final string g = " g";     final string kg = " kg";     final string mm = " mm";     final string cm = " cm";     final string m = " m";      switch(origmeasure){     case(oz):         newvalue = (value * oz_to_g);         break;     }     system.out.println(value + origmeasure + "=" + newvalue + newmeasure); } 

}

concatinate 2 strings , use case statement. if user inputs oz initial measurement, , g final measurement, have switch(initial + final) yield: ozg.

have case statement check each:

string orig = input.next();     string end = input.next();     switch(orig + end){     case "ozg": //do mathemetical function here result of oz --> g     }     }