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Start your free trialJake Basten
16,345 PointsNullPointerException in customer service coding challenge
Hey,
So as far i can tell my answer looks right, but im getting a NullPointer Exception when i pass customer in to the assist method... does this mean that there is no data in customer, or am i doing something wrong?
import java.util.ArrayDeque;
import java.util.Queue;
public class CallCenter {
Queue<CustomerSupportRep> mSupportReps;
public CallCenter(Queue<CustomerSupportRep> queue) {
mSupportReps = queue;
}
public void acceptCustomer(Customer customer) {
CustomerSupportRep csr;
/********************************************
* TODO (1)
* Wait until there is an available rep in the queue.
* While there is not one available, playHoldMusic
* HINT: That while assignmentcheck loop syntax we used to
* read files seems pretty similar
********************************************
*/
while (mSupportReps == null){
playHoldMusic();
}
/********************************************
* TODO (2)
* After we have assigned the rep, call the
* assist method and pass in the customer
********************************************
*/
csr = mSupportReps.poll();
csr.assist(customer);
/********************************************
* TODO (3)
* Since the customer support rep is done with
* assisting, put them back into the queue.
********************************************
*/
mSupportReps.add(csr);
}
public void playHoldMusic() {
System.out.println("Smooooooth Operator.....");
}
}
import java.util.List;
import java.util.ArrayList;
public class CustomerSupportRep {
private String mName;
private List<Customer> mAssistedCustomers;
public CustomerSupportRep(String name) {
mName = name;
mAssistedCustomers = new ArrayList<Customer>();
}
public void assist(Customer customer) {
System.out.printf("Hello %s, my name is %s, how can I assist you.%n",
customer.getName(),
mName);
System.out.println("...");
System.out.println("Is there anything else I can help you with?");
mAssistedCustomers.add(customer);
}
public List<Customer> getAssistedCustomers() {
return mAssistedCustomers;
}
}
public class Customer {
private String mName;
public Customer(String name) {
mName = name;
}
public String getName() {
return mName;
}
}
2 Answers
Florian Tönjes
Full Stack JavaScript Techdegree Graduate 50,856 PointsHey Jake,
you are checking if the mCustomerSupportReps is null, but it is not null as soon as the CallCenter constructor is called. Therefore it is always not null when a CallCenter is created. Just check if the size of the Queue is 0 instead.
while (mSupportReps.size() == 0){
playHoldMusic();
}
Best Regards, Florian
Jake Basten
16,345 PointsCheers Florian,
It's all so obvious when you know the answer haha!
Jake