Freemarker：意外指令，“</#if>”

Question

我的登录模板中有一些代码显示了用 freemarker 编写的错误凭据的错误。一切看起来都应该如何，语法正确，但 sparkjava 抛出 ParseException

freemarker.core.ParseException: Syntax error in template "freemarker/admin_login.ftl" in line 40, column 9:
Unexpected directive, "</#if>". Check if you have a valid #if-#elseif-#else structure.
at freemarker.core.FMParser.generateParseException(FMParser.java:5251)
at freemarker.core.FMParser.jj_consume_token(FMParser.java:5122)
at freemarker.core.FMParser.Root(FMParser.java:3433)
at freemarker.template.Template.<init>(Template.java:208)
at freemarker.cache.TemplateCache.loadTemplate(TemplateCache.java:495)
at freemarker.cache.TemplateCache.getTemplate(TemplateCache.java:409)
at freemarker.cache.TemplateCache.getTemplate(TemplateCache.java:261)
at freemarker.template.Configuration.getTemplate(Configuration.java:1786)
at freemarker.template.Configuration.getTemplate(Configuration.java:1646)
at spark.template.freemarker.FreeMarkerEngine.render(FreeMarkerEngine.java:69)
at pl.bluedotdevs.adminpanel.utils.ViewUtil.render(ViewUtil.java:22)
at pl.bluedotdevs.adminpanel.login.LoginController.lambda$static[=11=](LoginController.java:21)
at spark.RouteImpl.handle(RouteImpl.java:61)
at spark.http.matching.Routes.execute(Routes.java:61)
at spark.http.matching.MatcherFilter.doFilter(MatcherFilter.java:128)
at spark.embeddedserver.jetty.JettyHandler.doHandle(JettyHandler.java:50)
at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:189)
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:141)
at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:119)
at org.eclipse.jetty.server.Server.handle(Server.java:517)
at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:302)
at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:242)
at org.eclipse.jetty.io.AbstractConnection$ReadCallback.succeeded(AbstractConnection.java:245)
at org.eclipse.jetty.io.FillInterest.fillable(FillInterest.java:95)
at org.eclipse.jetty.io.SelectChannelEndPoint.run(SelectChannelEndPoint.java:75)
at org.eclipse.jetty.util.thread.strategy.ExecuteProduceConsume.produceAndRun(ExecuteProduceConsume.java:213)
at org.eclipse.jetty.util.thread.strategy.ExecuteProduceConsume.run(ExecuteProduceConsume.java:147)
at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:654)
at org.eclipse.jetty.util.thread.QueuedThreadPool.run(QueuedThreadPool.java:572)
at java.lang.Thread.run(Thread.java:745)

我的代码：

<#if($authenticationFailed)>
        <div class="alert alert-danger" role="alert">Niepoprawny email lub hasło</div>
    <#elseif($authenticationSucceeded)>
        <div class="alert alert-success" role="alert">Zalogowano pomyślnie</div>-->
    <#elseif($loggedOut)>
        <div class="alert alert-success" role="alert">Wylogowano pomyślnie</div>-->
    </#if>

真不知道怎么了。我查看了文档，我认为我的 elseif 语法很好。你能帮帮我吗？

Answer 1

条件中的括号导致解析错误（例如 <#if($authenticationFailed)>）。要么删除它们，要么正如@ddekany 在下面的评论中指出的那样，在 if 关键字和左括号之间放置一个 space。

此外，变量通常不以 $ 开头，但如果变量名称确实包含 $ 字符，则它会起作用。

试试这个。

<#if $authenticationFailed>
        <div class="alert alert-danger" role="alert">Niepoprawny email lub hasło</div>
<#elseif $authenticationSucceeded>
        <div class="alert alert-success" role="alert">Zalogowano pomyślnie</div>-->
<#elseif $loggedOut>
        <div class="alert alert-success" role="alert">Wylogowano pomyślnie</div>-->
</#if>

Answer 2

括号可能在您与 if 一起使用时导致异常。 Freemaker 中使用的表达式的具体示例是 -

When you supply value for interpolations: The usage of interpolations is ${expression} where expression gives the value you want to insert into the output as text. So ${(5 + 8)/2} prints "6.5" to the output (or possibly "6,5" if the language of your output is not US English).

如果是这样，您可以尝试使用 <#if ${authenticationFailed}>。

When you supply a value for the directive parameter: You have already seen the if directive in the Getting Started section. The syntax of this directive is: <#if expression>.... The expression here must evaluate to a boolean value. For example in <#if 2 < 3> the 2 < 3 (2 is less than 3) is an expression which evaluates to true.

在这种情况下，您也可以按照@Frank 的建议简单地使用 <#if authenticationFailed>。

注意 - 同样适用于您共享的代码中使用的所有条件分支。

来源 - Freemaker docs template

Freemarker：意外指令，“</#if>”

Freemarker: Unexpected directive, "</#if>"

java

freemarker