How to check the return data list is null?

[porkymin]

Hi all,
I have the following Collection declared as followed. How do i check whether the return collection is null or empty?

say i have: ml = getReport((List)mndDataLst);

I have tried to check whether return data list is null as described but it does not work.

if(ml == null || ml.isEmpty()){

//doesn't execute this block
}

Can anyone kindly advise me?


public static Collection getReport(List dataList) {
if (dataList == null || dataList.isEmpty()) {
return new ArrayList();
}
Collections.sort(dataList, new Comparator() {
public int compare(Object a, Object b) {
if (a != null && b !=null) {

Val[] v1 = ((ReportRow)a).getData();
String c = (String)v1[3].getData();

Val[] v2 = ((ReportRow)b).getData();
String d = (String) v2[3].getData();

return (c.compareTo(d));
}
else if (a== null && b !=null) {
return -1;
}
else
return 1;
}
});
return dataList;
}

 

[Diancecht]

Well, maybe the Collection is not empty ...

Did you try printing out the size of the collection?

Cheers,
Dian

 

[porkymin]

how to print out the size of the collection?

 

[Diancecht]

It has a size() method.

Cheers,
Dian