FreeMarker：需要一个哈希，但这已经评估为一个序列

Question

我知道同样的问题已经出现在这里。但不幸的是，它不能帮助我解决我的问题。我的 FreeMarker 模板中有 HashSet。我想在视图上显示 HashSet 的大小。为此，我有以下几点：

 <td>${repo.getRepoWords().size()}</td>

getRepoWords 方法是：

 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 模板中对 HashSet 使用 size() 方法吗？

Answer 1

我建议你使用?size，如下所示。请检查Document

${repo.repoWords?size}