Extended Example

A flexible numberic stack.

package numericstack;
import java.lang.reflect.Array;

import simplestack.*;

public class NumericStack {
    public static final int STKSIZE = 4;
    protected Object stack;
    protected int top = 0;
    public NumericStack(String className)
        throws ClassNotFoundException {
        stack =
            Array.newInstance(Class.forName(className), STKSIZE);
    }
    public void push(Object obj)
        throws StackOverflowException, IllegalArgumentException {
        try {
            Array.set(stack,top++,obj);
        } catch (ArrayIndexOutOfBoundsException e) {
            top = STKSIZE;
            throw new StackOverflowException();
        }
    }
    public Object pop() throws StackUnderflowException {
        try {
            return Array.get(stack,--top);
        } catch (Exception e) {
            top = 0;
            throw new StackUnderflowException(e.getMessage());
        }
    }
    public int top() {
        return top;
    }
}

import simplestack.StackOverflowException;
import numericstack.NumericStack;

/**
 * @author jack
 */
public class TestIt {

    public static void main(String[] args) {
        try {
            NumericStack stack = new NumericStack("java.lang.Integer");
            stack.push(new Integer(1));
            stack.push(new Integer(2));
        } catch (ClassNotFoundException e) {
            System.out.println(e);
        } catch (StackOverflowException e) {
            System.out.println(e);
        } catch (IllegalArgumentException e) {
            System.out.println(e);
        }
    }
}

Exercise: modify TestIt.java to generate each of the exception type caugth. You may test each exception one at a time.