I have an arraylist of Dept type, Now i want this data to be used in HashMap containing all the values of arraylist in it. how do i do it?

Question

I want to now make use of this ArrayList with all the values and put it in a hashMap. How do i do it? Please help. In hashMap, values from Dept class will be in key and value will be auto incremented.

public class Main {

    public static void main(String[] args) {
        List<Dept> list = new ArrayList<Dept>();

        Dept dept = new Dept("Mudit" , 4);
        list.add(dept);
        Dept dept1 = new Dept("Ashish" , 3);
        list.add(dept1);
        Dept dept2 = new Dept("Rahul" , 2);
        list.add(dept2);
        Dept dept3 = new Dept("Santos" , 3);
        list.add(dept3);

        Iterator<Dept> itr = list.iterator();
        while(itr.hasNext()) {
            System.out.println("values = " +itr.next());
        }

    }
}
class Dept {

    private String name;
    private int id;

    public Dept(String name, int id) {
        this.name = name;
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

}

Answer 1

Hashmap needs a unique key for each value . Here assuming id to be your key .

Hashmap<Integer,Dept> map=new HashMap(Integer,Dept);
for(Dept d:list)
{
map.put(d.getId(),d);
}