why is this code not running? it compiles but... import java.util.ArrayList; import java.util.Collections; import java.util.List; //import java.util.Random; public class EmployeeSorter { public static void main(String[] args) throws InterruptedException { List EmpList = new ArrayList(); for (int i = 1; i <= 10000; i++) { EmpList.add(new Employee(i, (int) (Math.random() * 2500 + 1500))); } List List1 = EmpList.subList(0, EmpList.size() / 2); List List2 = EmpList.subList(EmpList.size() / 2, EmpList.size()); Thread thread1 = new Thread(); Collections.sort(List1); Thread thread2 = new Thread(); Collections.sort(List2); thread1.start(); thread2.start(); thread1.join(); thread2.join(); int i = 0, j = 0; for (int k = 0; k < EmpList.size(); k++) { if (i < List1.size() && j < List2.size()) { if (List1.get(i).compareTo(List2.get(j)) < 0) { EmpList.set(k, List1.get(i++)); } else { EmpList.set(k, List2.get(j++)); } } else if (i < List1.size()) { EmpList.set(k, List1.get(i++)); } else { EmpList.set(k, List2.get(j++)); } } } }

This is the question

In this question, we need to divide, sort, and merge a list of Employees using the multithreading framework. Create a class named EMPLOYEE that holds the employees ID (integer value of unique value) and salary (integer value).

Step1: The main thread creates a list of 10,000 Employees with sequential IDs (1 to 10,000 to keep them unique) and randomly generated salaries (between 1500 to 4000); name this list EmpList.

Step2: Split the generated list EmpList into two lists of equal length: List1, and List2. Step3: Create two threads; each thread should sort the corresponding list (thread1 sorts List1, and thread2 sorts List2)

ascendingly with respect to the salary.

Step4: The main thread then waits for the two threads, then merge the two sorted sublists (List1 and List2) into the main list (EmpList) ascendingly with respect to the salary.