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);
}
}
}
}
2022-04-24 21:43:28
1.9MB
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