Nsryjdtyk

I'm trying to make a program that matches a clients interests with aspects of a holiday, I have an array list of holidays and an array list of strings for the clients interests and I wanted to create a new array list which would add all elements that are contained in both. This is what I have but it comes up with a null pointer exception, Any ideas where I've gone wrong?
the debugger points towards the disjoint and at " int c1size = c1.size();"
Relevant parts of code...

In main...

ClientExt1 marina = new ClientExt1("Marina",14321,"marina.calder1@btinternet.com");

ArrayList<String> interests = new ArrayList<>();

interests.add("History");

interests.add("Music");

marina.setInterests(interests);

holidaySeller.getHolidayMatches(marina);

Client...

public class ClientExt1 {



private String name;

private int id;

private String email;

private HolidayExt1 holidayBooked;

private ArrayList<String> interests;



public ClientExt1(String name, int id, String email){

    this.name=name;

    this.id=id;

    this.email=email;





}



public void setInterests(ArrayList interests) {

    this.interests=interests;

}



public ArrayList<String> getInterests(){

    return interests;

Company class...

public class CompanyExt1 {

    protected ArrayList<StaffExt1> staffMembers;                  

    protected ArrayList<HolidayExt1> holidays;

    protected ArrayList<GuideExt1> holidayGuides;

    protected ArrayList<AdventureExt1> adventureHolidays;

    protected ArrayList<CultureExt1> cultureHolidays;

    private ArrayList<String> matchedHolidays;





    public ArrayList<String> findHolidayMatch(ClientExt1 client) {

        ArrayList interests = client.getInterests();

        int i;

        for (i = 0; i < holidays.size() && i< interests.size(); i++) {

            if (!Collections.disjoint(holidays.get(i).getAspects(), interests)) {

                matchedHolidays.add(holidays.get(i).getName());



            }

        }

        return matchedHolidays;

    }



    public void getHolidayMatches(ClientExt1 client){

        System.out.println(client.getName() + ", the holidays recommended to you based on your interests from this company are:" + findHolidayMatch(client));

    }

}

You need to initialize holidays before you use it and matchedHolidays before you add values to it in findHolidayMatch

I would actually make matchedHolidays a local variable instead of a class member since it is only used in the scope of the findHolidayMatch method.