Question

got another issue.

Im trying to send an entire Map of objects and their associated keys so that it can be accessed from another class. The method I am using does not work, as I tried to use the same method that is used to pass an array list, but it does not work for a Map.

what would be the correct way of doing it?

this is what I have tried

public Map <Integer, Employee> getAllEmps()
{ 
     return (Map <Integer, Employee>) ;
}

and this is how I have declared it (the actual map itself)

private static  Map <Integer, Employee> employeeMap = new TreeMap<Integer,Employee>();    

Answer 1

You can return the variable itself:

public Map <Integer, Employee> getAllEmps()
{ 
     return employeeMap;
}

Which would allow anyone to modify the contnent of the map.

To prevent modification, you can return an unmodifiableMap:

public Map <Integer, Employee> getAllEmps()
{ 
     return Collections.unmodifiableMap(employeeMap);
}

Alternatively, you can return a copy:

public Map <Integer, Employee> getAllEmps()
{ 
     return new TreeMap<Integer,Employee>(employeeMap);
}