我知道相同的问题已经在这里。但不幸的是，这无助于我解决问题。我的FreeMarker模板中有HashSet。我想在视图上显示HashSet的大小。我对此有以下要求：
<td>${repo.getRepoWords().size()}</td>
方法getRepoWords是：
public HashSet getRepoWords() {
return repoWords;
}
结果我看到了这个异常
FreeMarker template error (DEBUG mode; use RETHROW in production!): For "." left-hand operand: Expected a hash, but this has evaluated to a sequence (wrapper: f.t.SimpleSequence): ==> repo.getRepoWords() [in template "repositories/detail.ftl" at line 24, column 23] ---- FTL stack trace ("~" means nesting-related): - Failed at: ${repo.getRepoWords().size()} [in template "repositories/detail.ftl" at line 24, column 21] ~ Reached through: #nested [in template "layouts/common.ftl" in macro "page" at line 20, column 1] ~ Reached through: @c.page title="Главная страница" [in template "repositories/detail.ftl" at line 2, column 1] ---- Java stack trace (for programmers): ---- freemarker.core.NonHashException: [... Exception message was already printed; see it above ...] at freemarker.core.Dot._eval(Dot.java:48) at freemarker.core.Expression.eval(Expression.java:83) at freemarker.core.MethodCall._eval(MethodCall.java:58) at freemarker.core.Expression.eval(Expression.java:83) at
我可以在FreeMarker模板中为HashSet使用size（）方法吗？