How to display an enum in a dropdown in Wicket

Its often useful to use an enum as the model for a dropdown (or radio group) in Wicket, but not immediately obvious how to handle the display of the values. Lets say I have an enum with three colors:

[sourcecode language=”java”]
enum Color { RED, GREEN, BLUE };
[/sourcecode]

I can hook this up to a dropdown with the following code:

[sourcecode language=”html”]

[/sourcecode]

[sourcecode language=”java”]
enum Color { RED, GREEN, BLUE };
private Color color = Color.GREEN;
add(new DropDownChoice(“color”, Arrays.asList(Color.values()), new EnumChoiceRenderer(this)));
[/sourcecode]

[sourcecode language=”java”]
Color.RED=Red
Color.GREEN=Green
Color.BLUE=Blue
[/sourcecode]

Now I get what I wanted – a dropdown displaying “Red”, “Green” and “Blue”.

Mockito

We just started using Mockito for unit testing of our Wicket applications. Its a great tool, allowing us to easily mock out our service layers on a test-by-test basis.

In the example below, we’re testing a page called ItemPage. It takes an id of an item to load – internally the page uses itemService.find(id) to load the item from the database. Using Mockito, we mock out the itemService.find call to return a test item.

[sourcecode language=”java”]
public class TestItemPage extends WicketTestcase {
private static final long serialVersionUID = 1L;

@Test
public void TestItemPage() {
when(itemService.find(Mockito.anyInt())).thenAnswer(new Answer() {

@Override
public Item answer(InvocationOnMock invocation) throws Throwable {
final int id = (Item) invocation.getArguments()[0];
Item item = new Item(id);
item.setTitle(“test”);
item.setDeadline(new Date());
return item;
}
});

tester.startPage(new ItemPage(12345));
tester.assertRenderedPage(ItemPage.class);
}
}
[/sourcecode]