Regarding Ordering the List

[surya.raaj prakash]

Hi Friends,

I have one requirement would you please help on this..

public List<Employee> getEmployeeList() {
        if (Employee== null) {
            employee= new ArrayList<Employee>();
        }
        return this.employee;

I have List object which contain three elements...from the preceding code we will get the list object..

My question is how to set the order number to each element in list so based on the order number we need to get the employee or how to write a logic to check the order and status to determine the next employee in the list?and and how to check this employee same as next employee from the employee list?

[Shanky Sohar]

For your requirement Map will be the best suited

[Parag Shah]

Java Lists allow duplicates, wheres a Set does not allow duplicates. If you want ordering, you can use a TreeSet which is an ordered set.

[Campbell Ritchie]

Parag Shah wrote: . . . TreeSet . . . is an ordered set.

No it isn't, it is a sorted set. If you need to retain insertion order, you want a LinkedHashSet or similar.

[Stephan van Hulst]

Campbell Ritchie wrote:No it isn't

Technically it is, how else could be it sorted? ;)

Surya, can you be more clear in what you need?

[surya.raaj prakash]

ok,stephan..

Actual requirement is..
I have been developed Three classes..
1.Approval.java it contains
"type",
"approvers",----> (

public List<Approver> getApprovers() {
        if (approvers == null) {
            approvers = new ArrayList<Approver>();
        }
        return this.approvers;
    }

)
"dateCreated" properties
2.Approver.java it contains
"employee",
"status",
"statusDate" properties
3.Employee.java ti contains
"employeeNbr",
"firstName",
"lastName",
"emailAddress",
"managerEmployeeNbr",
"managerInfo" properties

Here from Approval object we will get list of Approver object,from Approver object we will get employee object..right?
But i would want how to write a logic to check the order and status to determine the next approver in the list?or how to check this employee same as next employee who supposed to approve from the approvers list?

[Campbell Ritchie]

Stephan van Hulst wrote: . . . Technically it is, how else could be it sorted? ;) . . .

Good grief, there's somebdoy more pedantic than me out there

[Jesper de Jong]

Ok, so you have an Approval, which has a list of Approvers, and an Approver refers to an Employee and has a status.

surya.raaj prakash wrote:Here from Approval object we will get list of Approver object,from Approver object we will get employee object..right?

Yes.

surya.raaj prakash wrote:But i would want how to write a logic to check the order and status to determine the next approver in the list?or how to check this employee same as next employee who supposed to approve from the approvers list?

It's not exactly clear to me what you want to do with the approvers of an approval. You can ofcourse look at the status of each approver, and you can look at the Employee that each Approver refers to. Since the list of approvers is a list, it will be in a certain order. What exactly do you want to check there; if the order is correct? If that is what you want, then what are the rules for a correct order? I guess that you can check if two Employees are the same by comparing their employeeNbrs.

Can you explain exactly what you want to do with the Approvers of an Approval?

[Stephan van Hulst]

Surya, why is it important that you get them in a specific order? If you want to do this, you can create a Comparator object, and use either Collections.sort() to sort the List or use a SortedSet.

Campbell Ritchie wrote:Good grief, there's somebody more pedantic than I out there

[Mike Simmons]

Campbell Ritchie wrote:

Stephan van Hulst wrote: . . . Technically it is, how else could be it sorted? ;) . . .

Good grief, there's somebdoy more pedantic than me out there

He's not really any more pedantic - just more correct.