The problem is in your constructor in lines 36 and 37.
If
name refers to the argument of a constructor and
this.name to the instance variable of the class, what do you think this assignments do?
Other issues.
1. Your
Empl class should implement
Comparable, not
Comparator.
2. Do not compare
ints in a way you do in line 60. This might result in an overflow and incorrect value. Use
Integer.compare instead.
3.
You should give your classes and variables meaningful names. So your class should be
Employee, not
Empl. Your
sal variable should be
salary etc.
4. Is employee with
null name and
0 salary a valid one? If not, you do not need non-argument constructor.