A lonely program missing its other part?? ~o~

Question

My program was suppose to output the diameter,circumference and area of a circle with the input of the radius. For some reasons, it only run half way and never get to the print method.
thanks
guys
import java.io.*;  //package for Java input/output classes
public class Circle
     static class circleInfo
          String RESULT;                                   //Input action that determines what to be calculated
          float RADIUS;                                   //Input value for the radius of a Circle
          final float PI = 3.14159265F;               //Constant for PI
          double DIAM;
          double CIRUM;
          double AREA;
           public circleInfo() throws IOException //The main method of this program
               BufferedReader in;
               in =
                    new BufferedReader( new InputStreamReader( System.in ) );          //Input stream for strings
               System.out.println( "Please enter the radius of a Circle: " );                         //Prompt the user to enter the radius value
               RADIUS = Float.parseFloat (in.readLine() );                                                  //convert the input to a float, and assign it to 'radius' variable
               DIAM = RADIUS * 2;                                   //Calculates and returns the circle diameter
               CIRUM = 2 * RADIUS * PI     ;                         //Calculates and returns the circle circumference                                             
                  AREA = RADIUS * RADIUS * PI     ;                    //Calculates and returns the circle area                    
         public void printcircleInfo()
               System.out.println( "A circle with radius of" + RADIUS + " have:");
               System.out.println( "A Diameter of " + DIAM );
               System.out.println( "A Circumference of " + CIRUM);
               System.out.println( "And an Area of" + AREA);                         
public static void main(String[] args)throws IOException
     circleInfo testcircleInfo = new circleInfo();
     }//end main
}//end Circle

Answer 1

Yeah, drop the teacher and get a copy of Effective Java instead. And The Elements of Java Style.
You already have a nested class, although not an inner class. The nested class in this case is entirely pointless.
Ways you could improve your code:
- Don't get user input inside of the constructor.
The constructor will block (it won't finish) if input isn't provided on the console. That's bad. And since the object has nothing to do with I/O or parsing, it's bad that it could throw exceptions about that.
A much better approach would be to get the user input somewhere else, turn it into a number type somewhere else, and then finally create the circleInfo object using the number.
- Drop this weird Circle/circleInfo dichotomy. What's it supposed to mean? If I told you vocally (without looking at code) that there was a Circle and a CircleInfo, what would you think the difference would be? (In particular, if CircleInfo holds information about a circle, then what's Circle for?) You should use nested classes when they're useful, not just for the hell of it.
- Make the Circle class (since circleInfo no longer exists) immutable. Its fields should be final.
- Follow naming conventions