package pkk.IBS;

import java.util.ArrayList;

import java.util.Map;

import java.util.Set;

import java.util.concurrent.ConcurrentHashMap;

import java.util.concurrent.ConcurrentSkipListSet;

public class Impl {

public static void main(String[] args) {

ArrayList<Employee> list= new ArrayList();

list.add(new Employee(1,"Prashnat",4));

list.add(new Employee(2,"ajit",6));

list.add(new Employee(3,"sam",3));

list.add(new Employee(4,"Prashnat",7));

Impl e = new Impl();

/* System.out.println("Before removing " + list.toString());

for(Employee e1:list){

System.out.println("id " + e1.getId() + "name" + e1.getName() + "exp" + e1.getExp());

}*/

/**

* here while iterating list, I am trying to remove element from it.

* but its throwing java.util.ConcurrentModificationException

* to avoid this either we have to add all the element in new list and then

* remove all or we can implement concurrent hashset

*/

// e.concurrentError(list);

//e.removeelement(list);

e.concurrentModification(list);

}

private void removeelement(ArrayList<Employee> list) {

// TODO Auto-generated method stub

ArrayList list2 =new ArrayList<>();

for(Employee e:list){

if(e.getExp()>5){

list2.add(e);

/*list.remove(e);*/

}

else

continue;

}

list.removeAll(list2);

System.out.println("list2 = " + list2);

System.out.println("After removing " + list);

}

public void concurrentError(ArrayList<Employee> list){

System.out.println("List B4 :: " + list.toString());

for(Employee e : list){

if(e.getExp()>5){

list.remove(e);

}

}

System.out.println("List :: " + list.toString());

}

public void concurrentModification(ArrayList<Employee> list){

//int a=1;

System.out.println("List B4 :: " + list.toString());

Map<Integer,Employee> map = new ConcurrentHashMap<Integer,Employee>();

//inserting data into map

for(int a=0; a<list.size();a++){

for(Employee e : list){

map.put(a, list.get(a));

}

}

System.out.println("Map B4 :: "+ map.size() +" :: "+ map.toString());

//now trying go delete element while iterating

for(Map.Entry<Integer, Employee> e : map.entrySet()){

if(e.getValue().getExp() > 5){

//map.remove(e.getKey(), e);

map.put(7, new Employee(1,"Prashnat",4));

}

}

System.out.println("Map After :: "+ map.size() +" :: "+ map.toString());

}

// System.out.println("List :: " + list.toString());

}