Question

How to convert List of objects to HashMap using in Java

Answer 1

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
 
class Worker {
    private Integer ID;
    private String name;
    
    public Worker(){}
    
    public Worker(Integer ID, String name) {
        this.ID = ID;
        this.name = name;
    }    
    
    public Integer getID() {
        return ID;
    }
 
    public String getName() {
        return name;
    }

    public String toString(){
        return "[" + getID() + " : " + getName() + "]";
    }
}
 
public class MyClass {
    public static void main(String[] args) {

        List<Worker> list = new ArrayList<Worker>();
        
        list.add(new Worker(1, "Darth Vader") );
        list.add(new Worker(2, "Luke Skywalker") );
        list.add(new Worker(3, "Obi-Wan Kenobi") );
        list.add(new Worker(4, "Han Solo") );

        Map<Integer, Worker> hmap = new HashMap<Integer, Worker>();
        
        for (Worker w : list) {
            hmap.put(w.getID(), w);            
        }
                
        System.out.println(hmap);
    }
}



/*
run:

{1=[1 : Darth Vader], 2=[2 : Luke Skywalker], 3=[3 : Obi-Wan Kenobi], 4=[4 : Han Solo]}

*/

 

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