public static void main(String[] args) {
int result = 0;
Calculator myCalc = new Calculator();
try {
if (args.length != 1) {
throw new IllegalArgumentException("There must be exactly one argument! e.g. add(1, 2)");
}
if (!myCalc.checkBrackets(args[0])) {
throw new IllegalArgumentException(
"Brackets of the input expression \"" + args[0] + "\" do NOT match!");
}
/* Normalize the expression by removing all the whitespaces around
* opening/closing brackets and the comma separator.
* Any remaining whitespaces after the normalization will indicate
* an invalid expression during evaluation later on.
*/
/* Remove all white spaces before and after the opening and closing brackets
*/
String expr_v1 = args[0].replaceAll("(.)(\\s+)([()])(\\s+)(.)", "$1$3$5");
/* Remove all spaces before and after the separator ,
*/
String expr_v2 = expr_v1.replaceAll("(.)(\\s*)([,])(\\s*)(.)", "$1$3$5");
String expr_v3 = expr_v2.replaceAll("(.)([,])(\\s+)(.)", "$1$2$4");
myCalc.logger.setLevel(DEBUG);
result = myCalc.evaluateExpression(expr_v3);
/* Print the result only if the expression is valid. Otherwise, an error
* message has already been logged.
*/
System.out.println(result);
} catch (Exception e) {
myCalc.logger.log(ERROR, e.toString());
return;
}
}
