I'm submitting this code in a couple of days as part of an an interview process. The company knows that I don't have any formal experience with Java. I'm hoping they are testing my ability to learn it on the fly.
This is my first non-trivial Java program and I'm looking for improvements and advice as if to whether I'm following "best practice" Java.
The comments below explain a bit about the program and example input/output is posted below as well.
The rounding was a bit weird, as it was always up to the next .05 cents to satisfy the requirements.
The code can be tested here.
/*************************************************************************
* RUN AT: http://ideone.com/ZEPZVl
* REVIEWED AT:
*
* ASSUMPTIONS: That the input is well-formed. A group is terminated by
* an empty line of form "^\\s*$". Headings are of the form
* "^Input (\\d):". Monetary values are of the form
* "(\\sat) ([0-9]+\\.[0-9]+)".
*
* MODIFYING: Strings that mark food, books and medical supplies can be set
* in base_array. String that mark imports can be set in import_array.
*
* NOTE: This code was developed at ideone.com. The final empty line
* was not detected and I was required to put an END. I assume the
* the front end of the web-app was stripping trailing white space.
*
*************************************************************************/
import java.io.InputStream;
import java.util.Scanner;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
class Main {
public static void main (String[] args) {
try {
Taxer taxer = new Taxer();
taxer.run();
} catch (Exception e) {
e.printStackTrace();
}
}
}
class Taxer {
private String[] import_array = {"import"},
base_array = {"book", "chocolate", "pills"};
private Scanner scanner = new Scanner(System.in);
private final Pattern p_input = Pattern.compile("^Input (\\d):"),
p_money = Pattern.compile("(\\sat) ([0-9]+\\.[0-9]+)"),
p_empty = Pattern.compile("^\\s*$");
private final double TAX5 = .05,
TAX10 = .10;
private double tax_group_sum = 0,
price_group_sum = 0,
price,
tax_import,
tax_base;
private String line;
public void run() {
while(scanner.hasNext()) {
analyzeLine();
}
}
private void analyzeLine () {
Matcher m_input,
m_money,
m_empty;
line = scanner.nextLine();
m_input = p_input.matcher(line);
m_money = p_money.matcher(line);
m_empty = p_empty.matcher(line);
price = 0;
// heading
if (m_input.find()) {
System.out.println("Output " + m_input.group(1) + ":" );
// line containing money amount
} else if (m_money.find()) {
line = m_money.replaceFirst(": ");
price = Double.parseDouble(m_money.group(2));
checkTaxed();
checkImports();
addValues();
printLine();
// empty line
} else if(m_empty.find()) {
printTotal();
tax_group_sum = 0;
price_group_sum = 0;
// catch all echos input
} else {
System.out.println(line);
}
}
private boolean checkImports () {
Pattern p;
Matcher m;
tax_import = 0;
for (String s : import_array) {
p = Pattern.compile(s);
m = p.matcher(line);
if(m.find()) {
tax_import = roundSingleValue(price * TAX5);
return true;
}
}
return false;
}
private boolean checkTaxed() {
Pattern p;
Matcher m;
tax_base = 0;
for (String s : base_array) {
p = Pattern.compile(s);
m = p.matcher(line);
if(m.find()) {
return false;
}
}
tax_base = roundSingleValue(price * TAX10);
return true;
}
private double roundSingleValue (double value) {
double accuracy = 20;
value = value * accuracy;
value = Math.ceil(value);
value = value / accuracy;
return value;
}
private void addValues () {
double tax_total = tax_base + tax_import;
price = price + tax_total;
tax_group_sum += tax_total;
price_group_sum += price;
}
private void printTotal () {
System.out.printf("Sales Taxes: %.2f%n", tax_group_sum);
System.out.printf("Total: %.2f%n%n", price_group_sum);
}
private void printLine () {
System.out.print(line);
System.out.printf("%.2f%n", price);
}
}
/*
Input 1:
1 book at 12.49
1 music CD at 14.99
1 chocolate bar at 0.85
Input 2:
1 imported box of chocolates at 10.00
1 imported bottle of perfume at 47.50
Input 3:
1 imported bottle of perfume at 27.99
1 bottle of perfume at 18.99
1 packet of headache pills at 9.75
1 box of imported chocolates at 11.25
END
*/
/*
Output 1:
1 book: 12.49
1 music CD: 16.49
1 chocolate bar: 0.85
Sales Taxes: 1.50
Total: 29.83
Output 2:
1 imported box of chocolates: 10.50
1 imported bottle of perfume: 54.65
Sales Taxes: 7.65
Total: 65.15
Output 3:
1 imported bottle of perfume: 32.19
1 bottle of perfume: 20.89
1 packet of headache pills: 9.75
1 box of imported chocolates: 11.85
Sales Taxes: 6.70
Total: 74.68
END
*/
