SSD3答案 完整版

卡耐基梅陇的SSD课程答案 import java.io.*; import java.util.*; /* DOCUMENT THIS CLASS */ public class ShoppingCartApplication { private static BufferedReader stdIn = new BufferedReader( new InputStreamReader(System.in)); private static PrintWriter stdOut = new PrintWriter(System.out, true); private static PrintWriter stdErr = new PrintWriter(System.err, true); private ShoppingCart cart; /* DOCUMENT THIS PUBLIC METHOD */ public static void main(String[] args) throws IOException { ShoppingCartApplication application = new ShoppingCartApplication(); application.run(); } private void run() throws IOException { cart = new ShoppingCart(); int choice = getChoice(); while (choice != 0) { if (choice == 1) { cart.addProduct(readProduct()); } else if (choice == 2) { stdOut.println(cart.toString()); } else if (choice == 3) { stdOut.println(cart.getTotalValue()); } choice = getChoice(); } } private int getChoice() throws IOException { do { int input; try { stdErr.println(); stdErr.print("[0] Quit\n" + "[1] Add Product\n" + "[2] Display Products\n" + "[3] Display Total\n" + "choice>"); stdErr.flush(); input = Integer.parseInt(stdIn.readLine()); if (0 <= input && 3 >= input) { return input; } else { stdErr.println("Invalid choice: " + input); } } catch (NumberFormatException nfe) { stdErr.println(nfe); } } while (true); } private Product readProduct() throws IOException { final String DELIM = "_"; String name = ""; int quantity = 0; double price = 0.0; /* PLACE YOUR CODE HERE */ for (;;) { try { stdErr.print("product [name_qty_price]> "); stdErr.flush(); String s = stdIn.readLine(); StringTokenizer st = new StringTokenizer(s, DELIM); if (st.countTokens() != 3) { stdErr.println("Invalid input"); } else { name = st.nextToken(); quantity = Integer.parseInt(st.nextToken()); price = Double.parseDouble(st.nextToken()); if ((quantity >= 0) && (price >= 0.0D)) { return new Product(name, quantity, price); } stdErr.println("Invalid input"); } } catch (NumberFormatException iae) { stdErr.println(iae); } } } }