package ornek03; import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Map; public class School { public static void main(String[] args) { HashMap<Integer, Person> personMap = new HashMap<>(); Person p1 = new Person(1, "jon"); Person p2 = new Person(2, "dany"); Person p3 = new Person(3, "arya"); Person p4 = new Person(4, "ned"); personMap.put(10, p1); personMap.put(20, p2); personMap.put(30, p3); personMap.put(40, p4); for(Map.Entry<Integer, Person> e : personMap.entrySet()) { // System.out.println(e.getKey() + " - "+ e.getValue().getName()); } //System.out.println(personMap.get(30).getName()); // personMap.values().forEach(x -> System.out.println(x.getName())); HashMap<String, HashMap<String, HashMap<Integer, Person>>> pList = new HashMap<String, HashMap<String,HashMap<Integer,Person>>>(); HashMap<String, HashMap<Integer, Person>> students = new HashMap<String, HashMap<Integer, Person>>(); Person s1 =new Person(6, "catelyn"); Person s2 =new Person(7, "rob"); Person s3 =new Person(8, "sansa"); Person s4 =new Person(9, "robin"); students.put("s1", personMap); // students.put("s2", s2); // students.put("s3", s3); // students.put("s4", s4); pList.put("d1", students); //System.out.println(pList.values()); List<string> nameList = new ArrayList<>(); for(Map.Entry<String, HashMap<String, HashMap<Integer, Person>>> p : pList.entrySet()) { // System.out.println(p.getKey() + "-" ); for(Map.Entry<String, HashMap<Integer, Person>> x : p.getValue().entrySet()) { // System.out.println(x.getKey() + " -"); for(Map.Entry<Integer, Person> y : x.getValue().entrySet()) { System.out.println(y.getKey() + "-" + y.getValue().getName()); nameList.add(y.getValue().getName()); } } } System.out.println("Name List"); for (String string : nameList) { System.out.println(string); } } }