i used the solution from early java objects chapter 5 question 30

here is my code fro the driver

public class AutoPolicyDriver {

public static void main(String[] args) {

AutoPolicy policy1 = new AutoPolicy(11111111, "Toyota Camry", "NJ");

policyIsNoFaultState(policy1);

AutoPolicy policy2 = new AutoPolicy(22222222, "Ford Fusion", "WI");

policyIsNoFaultState(policy2);

}

public static void policyIsNoFaultState(AutoPolicy policy) {

System.out.println("The auto policy:");

System.out.printf("Account #: %d; Car: %s;%nState %s %s a no-fault state%n%n", policy.getAccountNumber(), policy.getMakeAndModel(), policy.getState(), (policy.isNoFaultState() ? "is": "is not" ));

}

}

here the code for method called

public class AutoPolicy {

private int accountNumber;

private String makeAndModel;

private String state;

public AutoPolicy (int accountNumber, String makeAndModel, String state) {

this.accountNumber = accountNumber;

this.makeAndModel = makeAndModel;

setState(state);

}

public void setAccountNumber(int accountNumber) {

this.accountNumber = accountNumber;

}

public int getAccountNumber() {

return accountNumber;

}

public void setMakeAndModel(String makeAndModel) {

this.makeAndModel = makeAndModel;

}

public String getMakeAndModel() {

return makeAndModel;

}

public void setState(String state) {

if(state.equals("CT") || state.equals("MA") || state.equals("ME") || state.equals("NH")

|| state.equals("NJ") || state.equals("NY") || state.equals("PA") || state.equals("VT")) {

this.state = state;

}

else {System.out.println("Invalid state code");}

}

public String getState() {

return state;

}

public boolean isNoFaultState() {

boolean noFaultState;

switch (getState()) {

case "CT":

case "MA":

case "ME":

case "NH":

case "NJ":

case "NY":

case "PA":

case "VT":

noFaultState = true;

break;

default:

noFaultState = false;

break;

}

return noFaultState;

}

}

the out put from the example is

Invalid state code

The auto policy:

Account #: 11111111, Car: Toyota Camry,

State MA is a no-fault state

The auto policy:

Execption java.lanhg.NullPointerException

my output is

The auto policy:

Account #: 11111111; Car: Toyota Camry;

State NJ is a no-fault state

Invalid state code

The auto policy:

Exception in thread "main" java.lang.NullPointerException

at AutoPolicy.isNoFaultState(AutoPolicy.java:44)

at AutoPolicyDriver.policyIsNoFaultState(AutoPolicyDriver.java:18)

at AutoPolicyDriver.main(AutoPolicyDriver.java:12)

was wondering why the difference