NullPointerException while trying to store array of multiple fields

While trying to make a request and pass data from Ajax to Spring Controller, null data mapped to ModelAttribute.

Ajax Call:

var i = 0;

var pFirstName=$("#pFirstName").val();
var pLastName=$("#pLastName").val();
var pAge=$("#pAge").val();
var pEmail=$("#pEmail").val();
var pContactNo=$("#pContactNo").val();

var serviceType=[];
var clinicName=[];
var providerCity=[];
var insuranceType=[];
var procedureDate=[];
var providerFName=[];
var pPrice=[];
var totalPrice=[];
for (i=1; i<=addFeedbackMore; i++) {
    if (!isEmptyOrBlank($("#serviceType"+i).val())) {
        serviceType[i-1]=($("#serviceType"+i).val());
    }           
    if (!isEmptyOrBlank($("#clinicName"+i).val())) {
        clinicName[i-1]=($("#clinicName"+i).val());
    }           
    if (!isEmptyOrBlank($("#providerCity"+i).val())) {
        providerCity[i-1]=($("#providerCity"+i).val());
    }           
    if (!isEmptyOrBlank($("#insuranceType"+i).val())) {
        insuranceType[i-1]=($("#insuranceType"+i).val());
    }           
    if (!isEmptyOrBlank($("#procedureDate"+i).val())) {
        procedureDate[i-1]=($("#procedureDate"+i).val());
    }           
    if (!isEmptyOrBlank($("#providerFName"+i).val())) {
        providerFName[i-1]=($("#providerFName"+i).val());
    }           
    if (!isEmptyOrBlank($("#pPrice"+i).val())) {
        pPrice[i-1]=($("#pPrice"+i).val());
    }           
    if (!isEmptyOrBlank($("#totalPrice"+i).val())) {
        totalPrice[i-1]=($("#totalPrice"+i).val()); 
    }           
}

$.ajax({
    type : "POST",
    url : "/feedback/feedbackDeatils",
    data : JSON.stringify({
           "pFirstName":pFirstName,
           "pLastName":pLastName,
           "pAge":pAge,
           "pEmail":pEmail,
           "pContactNo":pContactNo,
           "serviceType": serviceType,
           "clinicName": clinicName,
           "providerCity": providerCity,
           "insuranceType": insuranceType,
           "procedureDate": procedureDate,
           "providerFName": providerFName,
           "pPrice": pPrice,
           "totalPrice": totalPrice  
    }),
    contentType: 'application/json',
    success : function(response) {
       // do something ...
        restricted = false;
        restrictedFlag = 1;
        $('#gridSystemModal').modal('hide');
    },
    error : function(e) {
       alert('Error: ' + e);
    }
});

Spring Controller:

@RequestMapping(value="/feedbackDeatils", method = {RequestMethod.GET,   RequestMethod.POST})
public @ResponseBody List<Provider> getProviderList(@ModelAttribute     FeedbackDetails feedbackData) throws ParseException {

    feedbackService.insertFeedbackDetails(feedbackData);

    return null;
}

Bean Class: public class FeedbackDetails {

private String pFirstName;
private String pLastName;
private String pAge;
private String pEmail;
private String pContactNo;
private List<String> serviceType;
private List<String> clinicName;
private List<String> providerCity;
private List<String> insuranceType;
private List<String> procedureDate;
private List<String> providerFName;
private List<String> pPrice;
private List<String> totalPrice;

public String getPFirstName() {
    return pFirstName;
}
public void setPFirstName(String pFirstName) {
    this.pFirstName = pFirstName;
}
public String getPLastName() {
    return pLastName;
}
public void setPLastName(String pLastName) {
    this.pLastName = pLastName;
}
public String getPAge() {
    return pAge;
}
public void setPAge(String pAge) {
    this.pAge = pAge;
}
public String getPEmail() {
    return pEmail;
}
public void setPEmail(String pEmail) {
    this.pEmail = pEmail;
}
public String getPContactNo() {
    return pContactNo;
}
public void setPContactNo(String pContactNo) {
    this.pContactNo = pContactNo;
}
public List<String> getServiceType() {
    return serviceType;
}
public void setServiceType(List<String> serviceType) {
    this.serviceType = serviceType;
}
public List<String> getClinicName() {
    return clinicName;
}
public void setClinicName(List<String> clinicName) {
    this.clinicName = clinicName;
}
public List<String> getProviderCity() {
    return providerCity;
}
public void setProviderCity(List<String> providerCity) {
    this.providerCity = providerCity;
}
public List<String> getInsuranceType() {
    return insuranceType;
}
public void setInsuranceType(List<String> insuranceType) {
    this.insuranceType = insuranceType;
}
public List<String> getProcedureDate() {
    return procedureDate;
}
public void setProcedureDate(List<String> procedureDate) {
    this.procedureDate = procedureDate;
}
public List<String> getProviderFName() {
    return providerFName;
}
public void setProviderFName(List<String> providerFName) {
    this.providerFName = providerFName;
}
public List<String> getPPrice() {
    return pPrice;
}
public void setPPrice(List<String> pPrice) {
    this.pPrice = pPrice;
}
public List<String> getTotalPrice() {
    return totalPrice;
}
public void setTotalPrice(List<String> totalPrice) {
    this.totalPrice = totalPrice;
}
}

And while trying to get data, getting NullPointerException.