How Can I Use Comparators and Collections In Order To Sort A Text File In Different Ways? (Java)?

Question

Any ideas? How Can I Use Comparators and Collections In Order To Sort A Text File In Different Ways? (Java)?

Answer 1

you've almost got it right:

For comparing integers use the following:

Integer.compareTo(int1, int2);

For comparing strings use:

string1.compareTo(string2);

For boolean types use:

Boolean.compare(boolean1, boolean2);

So you Comparator class will be the following:

new Comparator< EmployeeFX >(){

            @Override
            public int compare(EmployeeFX o1, EmployeeFX o2) {
                return Integer.compare(o1.getId(), o2.getId());
            }
        };

Answer 2

Comparator is basically used to create multiple sort sequence. you can sort your object using any attribute.

Just one example for your reference.

public int compare(EmployeeFX emp1, EmployeeFX emp2) {

    return (emp1.getId() < emp2.getId()) ? -1
            : (emp1.getId() > emp2.getId()) ? 1 : 0;
}

Answer 3

What is your expected out put.

In this case u get the data sorted with salary wise(That is your last sort). All other previous sort become irrelevant.