1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/samples/composition/src-api2.0-runtime/org/apidesign/math/Arithmetica.java	Sat Feb 14 17:30:06 2009 +0100
     1.3 @@ -0,0 +1,72 @@
     1.4 +package org.apidesign.math;
     1.5 +
     1.6 +import org.apidesign.math.Arithmetica;
     1.7 +import org.apidesign.runtime.check.RuntimeCheck;
     1.8 +
     1.9 +/** Class to simplify arithmetical operations, improved version to compute
    1.10 + * the sum for ranges, but only if the virtual machine is configured to
    1.11 + * run in incompatible mode.
    1.12 + *
    1.13 + * @author Jaroslav Tulach <jtulach@netbeans.org>
    1.14 + * @version 2.0
    1.15 + */
    1.16 +public class Arithmetica {
    1.17 +    public int sumTwo(int one, int second) {
    1.18 +        return one + second;
    1.19 +    }
    1.20 +    
    1.21 +    public int sumAll(int... numbers) {
    1.22 +        if (numbers.length == 0) {
    1.23 +            return 0;
    1.24 +        }
    1.25 +        int sum = numbers[0];
    1.26 +        for (int i = 1; i < numbers.length; i++) {
    1.27 +            sum = sumTwo(sum, numbers[i]);
    1.28 +        }
    1.29 +        return sum;
    1.30 +    }
    1.31 +    
    1.32 +    public int sumRange(int from, int to) {
    1.33 +        if (calledByV2AwareLoader()) {
    1.34 +            return sumRange2(from, to);
    1.35 +        } else {
    1.36 +            return sumRange1(from, to);
    1.37 +        }
    1.38 +    }
    1.39 +
    1.40 +    private int sumRange1(int from, int to) {
    1.41 +        int len = to - from;
    1.42 +        if (len < 0) {
    1.43 +            len = -len;
    1.44 +            from = to;
    1.45 +        }
    1.46 +        int[] array = new int[len + 1];
    1.47 +        for (int i = 0; i <= len; i++) {
    1.48 +            array[i] = from + i;
    1.49 +        }
    1.50 +        return sumAll(array);
    1.51 +    }
    1.52 +    
    1.53 +    private int sumRange2(int from, int to) {
    1.54 +        return (from + to) * (Math.abs(to - from) + 1) / 2;
    1.55 +    }
    1.56 +
    1.57 +    private static boolean calledByV2AwareLoader() {
    1.58 +        // BEGIN: design.composition.arith2.6.runtime
    1.59 +        StackTraceElement[] arr = Thread.currentThread().getStackTrace();
    1.60 +        ClassLoader myLoader = Arithmetica.class.getClassLoader();
    1.61 +        for (int i = 0; i < arr.length; i++) {
    1.62 +            ClassLoader caller = arr[i].getClass().getClassLoader();
    1.63 +            if (myLoader == caller) {
    1.64 +                continue;
    1.65 +            }
    1.66 +            if (RuntimeCheck.requiresAtLeast("2.6", "api.Arithmetica", caller)) {
    1.67 +                return true;
    1.68 +            }
    1.69 +            return false;
    1.70 +        }
    1.71 +        return true;
    1.72 +        // END: design.composition.arith2.6.runtime
    1.73 +    }
    1.74 +    
    1.75 +}