Can any one suggest how to sort this list in velocity ?
So far I tried
#foreach($it in ${pro.test}.sort(${pro.test.sortOrder}))
.........
#end
But it is throwing error, Also I tried with
#foreach($it in ${pro.test.sort(${pro.test.sortOrder})})
.........
#end
this time no error but the control is not coming inside loop,
First, using ${...} is a way of helping the Velocity parser know exactly what you consider to be Velocity code. Normally, when velocity sees $something.somethingElse.somethingMore, it tries to parse as much as it can until it sees a word breaking character, such as a space or comma. When it sees ${something.somethingElse}.somethingMore, it only reads until the matching } as actual code, the rest is plain text. This means that ${pro.test}.sort(...) considers .sort(...) as plain text that should be printed, so it wouldn't call it as a method. That's why the first example fails with an error. You only need to use the formal syntax outside directives, though, you can just remove all the { and } from the call when inside #foreach(...).
Second, #foreach is very lax, it doesn't complain when you try to pass something invalid in the iterated scope; if it doesn't resolve to a valid list, then it simply ignores it and considers that there's nothing to iterate over. When something doesn't work as expected, print the values you're working with:
$pro.test $pro.test.class $pro.test.sortOrder $pro.test.sortOrder.class
#foreach ($it in ${pro.test.sort(${pro.test.sortOrder})})
...
#end
What does that print? Is $pro.test really a set? Is $pro.test.sortOrder a valid sort order specification, as expected by SortTool?
If $pro.test is a standard implementation of the Set interface, then there's no sort or sortOrder method. Assuming that the Velocity SortTool is available under the $sorter variable, you could try, for starters:
#foreach ($it in $sorter.sort($pro.test))
...
#end
Now, what exactly is $pro.test.sortOrder supposed to be? If it's a property, then note that for security reasons Velocity doesn't allow access directly to properties, it can only call methods. As a means of simplifying the syntax, $pro.test.sortOrder will actually try to call one of these: getsortOrder(), getSortOrder(), get("sortOrder"), issortOrder(), isSortOrder().
