Question

I’m trying to use a com.google.common.collect.Multimap<String, Foo> from Freemarker.

In a Multimap, for each key in the map, you get back Collection.

I tried the following but it didn’t work:

Java:

context.put("itemsByCategory", itemsByCategory);

FreeMarker:

<#list exclusiveItems?keys as cat>
    ${cat}<br/>
    <#assign items = exclusiveItems[cat]>
    <#list items as item>
        ${item.id}
    </#list>
</#list>

I got the following exception. It appears it’s treating Items as a scalar, although it’s actually a Collection.

?size is unsupported for: freemarker.ext.beans.SimpleMethodModel
The problematic instruction:
----------
==> list items as item [on line 61, column 49 in email/foo/foo-html.ftl]
----------

Java backtrace for programmers:
----------
freemarker.template.TemplateModelException: ?size is unsupportefor:freemarker.ext.beans.SimpleMethodModel

Answer 1

I found a solution that works.

Instead of passing in a Multimap instance (“itemsByCategory”), as in the example, I found that transforming the Multimap to a raw Map> and then using that works with the FreeMarker snippet above unchanged.

Hope this helps someone.