Junit单元测试

与运算相关的代码

    // 自定义除法运算,两种形式
    public static String division(String str1, String str2) {
        if(str2.equals("0"))
        {
            try {
                throw(new Exception("除数不能为0"));
            } catch (Exception e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
        
        int[] a = decompose(str1);
        int[] b = decompose(str2);
        int c = (a[0] * a[2] + a[1]) * b[2];
        int d = a[2] * (b[0] * b[2] + b[1]);

        return division(c, d);

    }
　　　　
　　　　　　　　　　
    public static String division(int str1, int str2) {        
        
        if (str1 % str2 == 0) {
            return String.valueOf(str1 / str2);
        }
        int[] str = reduction(str1, str2);
        if (str1 > str2) {
            int s = str[0] / str[1];
            int t = str[0] - str[1] * s;
            return s + "‘" + t + "/" + str[1];
        } else {
            return str[0] + "/" + str[1];
        }

    }



　　　　

    // 自定义乘法运算
    public static String mutip(String str1, String str2) {
        int[] a = decompose(str1);
        int[] b = decompose(str2);
        int c = (a[0] * a[2] + a[1]) * (b[0] * b[2] + b[1]);
        int d = a[2] * b[2];

        return division(c, d);

    }
    // 自定义加法运算
    public static String addition(String str1, String str2) {
        int[] a = decompose(str1);
        int[] b = decompose(str2);
        int c = ((a[0] * a[2] + a[1]) * b[2]) + ((b[0] * b[2] + b[1]) * a[2]);
        int d = a[2] * b[2];
        return division(c, d);

    }
    // 自定义减法运算
    public static String subtraction(String str1, String str2)  {

        int[] a = decompose(str1);
        int[] b = decompose(str2);
        int c = ((a[0] * a[2] + a[1]) * b[2]) - ((b[0] * b[2] + b[1]) * a[2]);
        int d = a[2] * b[2];
        return division(c, d);

    }
    // 约分
    private static int[] reduction(int a, int b) {

        for (int i = 2; i < RANG / 2; i++) {

            while (a % i == 0 && b % i == 0) {
                a = a / i;
                b = b / i;
            }

        }
        int[] as = { a, b };
        return as;
    }


    private static int[] decompose(String str) {

        int[] container = new int[3];
        if (str.contains("‘")) {
            container[0] = Integer.parseInt(str.split("‘")[0]);
            container[1] = Integer.parseInt(str.split("‘")[1].split("/")[0]);
            container[2] = Integer.parseInt(str.split("‘")[1].split("/")[1]);
        } else if (str.contains("/")) {
            container[0] = 0;
            container[1] = Integer.parseInt(str.split("/")[0]);
            container[2] = Integer.parseInt(str.split("/")[1]);
        } else {
            container[0] = 0;
            container[1] = Integer.parseInt(str);
            container[2] = 1;
        }
        return container;

    }