Sorting ArrayList Values inside a TreeMap

[Dinesh Kumar Durairaj]

I have a TreeMap<String, ArrayList<SampleVO>>

i need to sort by attributes in VO. How do i do that?

Here is the VO

public class SampleVO{
private String name;
private String id;

//getters and setters
}

[Seetharaman Venkatasamy]

Welcome to Javaranch Dinesh

well, how do you sort ArrayList<SampleVO> ?

[Dinesh Kumar Durairaj]

Thanks for Welcoming me

seetharaman venkatasamy wrote:Welcome to Javaranch Dinesh

well, how do you sort ArrayList<SampleVO> ?

I need to sort the VOs in the ArrayList by some attribute of VO like id or name. or is it not possible ? :|

If input is
mapkey1,arrlistvo1->arrlistvo1(somevo1,somevo2...)->somevo1("xyz",1),somevo2("abc",2)

The result of sorting VO by name should be

mapkey1,arrlistvo1->arrlistvo1(somevo2,somevo1...)->somevo2("abc",2),somevo1("xyz",1)

The result of sorting VO by id should be

mapkey1,arrlistvo1->arrlistvo1(somevo1,somevo2...)->somevo1("xyz",1),somevo2("abc",2)

[Marco Ehrentreich]

Hi Dinesh,

the general solution to your original problem is that you would define a Comparator for the TreeMap which is used to compare any two elements (=ArrayList<SampleVO>) of the TreeMap and decides which one should be before or after the other. But nevertheless YOU as a developer have to define what makes your ArrayLists comparable and defines the order when compared with another ArrayList.

Marco

[Dinesh Kumar Durairaj]

Thanks for the response, Marco

I implemented Comparator interface on the VO and override compareTo method based on your suggestion.

TreeMap values were sorted based on the keyname.