| Methods Summary |
|---|
| public static void | main(java.lang.String[] args)Main Method.
CUSTOMERS = new HashSet();
try {
Customer customer = null;
HashSet purchs = null;
// -- Joe
customer = new Customer();
customer.setName("Joe");
purchs = new HashSet();
purchs.add(new Purchase("Cat Food", 22.34f));
purchs.add(new Purchase("Cat Treats", 5.45f));
purchs.add(new Purchase("Cat Toy", 12.95f));
customer.setPurchases(purchs);
customer.setPurchases2(purchs);
customer.setPurchases3(purchs);
CUSTOMERS.add(customer);
// -- Jon
customer = new Customer();
customer.setName("Jon");
purchs = new HashSet();
purchs.add(new Purchase("Dog Food", 35.95f));
purchs.add(new Purchase("Dog Toy", 9.24f));
customer.setPurchases(purchs);
customer.setPurchases2(purchs);
customer.setPurchases3(purchs);
CUSTOMERS.add(customer);
// -- Jane
customer = new Customer();
customer.setName("Jane");
purchs = new HashSet();
customer.setPurchases(purchs);
customer.setPurchases2(purchs);
customer.setPurchases3(purchs);
CUSTOMERS.add(customer);
} catch (final Exception ex) {
ex.printStackTrace();
}
try {
Iterator iter = CUSTOMERS.iterator();
Customer customer = null;
while (iter.hasNext()) {
customer = (Customer)iter.next();
someFunction(customer);
makeCustomerReport(customer);
}
} catch (final ClassCastException ex) {
System.out.println("--- See? I told you. ---");
ex.printStackTrace(System.out);
System.out.flush();
}
System.out.println();
System.out.println("--------------------------------------");
System.out.println();
// -- Write out the two types of report to show that they
// do the same thing. Note that the order might be slightly
// different due to the nature of Set iterators.
makeGroupReport(CUSTOMERS);
System.out.println();
System.out.println("--------------------------------------");
System.out.println();
makeGroupReportBetter(CUSTOMERS);
|
| public static void | makeCustomerReport(Customer customer)Make a purchases report for a customer.
if (customer == null) {
throw new NullPointerException();
}
Set purchases = customer.getPurchases();
if (purchases != null) {
Iterator iter = purchases.iterator();
Purchase purch = null;
System.out.println("Purchases for " + customer.getName());
while (iter.hasNext()) {
purch = (Purchase)iter.next();
System.out.println(purch.getItemName() + "\t" + purch.getPrice());
}
}
|
| public static void | makeGroupReport(java.util.Set customers)Prepare a report of purchases for the given customers. Example with potential
null in Set peoperties.
if (customers == null) {
throw new NullPointerException();
}
Iterator purchaseIter = null;
Iterator customerIter = null;
Set purchases = null;
Customer customer = null;
Purchase purch = null;
customerIter = customers.iterator();
while (customerIter.hasNext()) {
customer = (Customer)customerIter.next();
System.out.println("Purchases for " + customer.getName());
purchases = customer.getPurchases3();
if (purchases != null) {
purchaseIter = purchases.iterator();
while (purchaseIter.hasNext()) {
purch = (Purchase)purchaseIter.next();
System.out.println(purch.getItemName() + "\t" + purch.getPrice());
}
}
System.out.print("Total Purchases = ");
if (purchases != null) {
System.out.println(purchases.size());
} else {
System.out.println(0);
}
System.out.println();
}
|
| public static void | makeGroupReportBetter(java.util.Set customers)Prepare a report of purchases for the given customers. Example with potential no
nulls in Set peoperties.
if (customers == null) {
throw new NullPointerException();
}
Iterator purchaseIter = null;
Iterator customerIter = null;
Set purchases = null;
Customer customer = null;
Purchase purch = null;
customerIter = customers.iterator();
while (customerIter.hasNext()) {
customer = (Customer)customerIter.next();
System.out.println("Purchases for " + customer.getName());
purchases = customer.getPurchases3();
purchaseIter = customer.getPurchases3()
.iterator();
while (purchaseIter.hasNext()) {
purch = (Purchase)purchaseIter.next();
System.out.println(purch.getItemName() + "\t" + purch.getPrice());
}
System.out.println("Total Purchases = " + purchases.size());
System.out.println();
}
|
| public static void | someFunction(Customer customer)Manipulate a customer.
if (customer == null) {
throw new NullPointerException();
}
Set purchs = customer.getPurchases();
Set names = new HashSet(); // going to use to store customer names.
names.add(new String("Jason"));
purchs.add(new String("Fred")); // typo, he meant names, not purchs.
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