Freemaker 操作后端hashmap+json array嵌套

Freemaker 操作后端hashmap+json array嵌套

这个问题，是因为多层嵌套，导致直接用hashmap[key]获取json array值，不能直接用于list遍历。

解决方案如下：

后端

List<JSONObject> allArticlesInDomains = new ArrayList<>();
        int pageNum = 1, pageSize = 10;
        for(JSONObject jb:domains){
            final String domainId = jb.optString(Keys.OBJECT_ID);
            final String domainName = jb.optString("domainTitle");
            final List<JSONObject> latestArticles = (List<JSONObject>) articleQueryService.getDomainArticles(domainId, pageNum, pageSize).opt(Article.ARTICLES);
            final JSONObject result = new JSONObject().put(domainName,latestArticles);
            allArticlesInDomains.add(result);
        }
        dataModel.put("allArticlesInDomains", allArticlesInDomains);

前端

.ftl内容

<#assign keys=articlesInDomains.keySet()/>
<#list keys as k>
    <span>${k}</span>
    <ul>
        <#assign json = articlesInDomains[k]?eval/>
        <#list json as article>
            <#include "common/list-item.ftl">
        </#list>
        <#if json?size == 0>
            <li class="ft-center">
                <br><br>
                ${systemEmptyLabel}<br>
                ${systemEmptyTipLabel}<br>
                <img src="${staticServePath}/images/404/5.gif"/>
            </li>
        </#if>
        <li>
            <a class="more" href="${servePath}/recent">${moreRecentArticleLabel}</a>
        </li>
    </ul>
</#list>

例外

如果string中包含Unicode字符，可能出现如下异常：

FreeMarker template error:
Failed to "?eval" string with this error:

---begin-message---
Syntax error in ?eval-ed string in line 1, column 5535:
Lexical error: encountered "u" (117), after "\"\u5b89\u5927\u7b80\u300a\u7ef8\u7f2a\u300b\u6284\u5199\u5728\\".
---end-message---

The failing expression:
==> articlesInDomains[k]?eval  [in template "classic/index.ftl" at line 54, column 57]

----
FTL stack trace ("~" means nesting-related):
        - Failed at: #assign json = articlesInDomains[k]?eval  [in template "classic/index.ftl" at line 54, column 41]
----

Java stack trace (for programmers):