Restore support for Freemarker request parameters and taglibs now that it supports Jakarta

[anabright]

I just upgraded my app to Spring Boot 3.0.5 (and consequently Spring 6.0.7) and there seems to be something broken with spring-boot-starter-freemarker.

In my Freemarker template, I have this line that used to work before the upgrade:

<div>${RequestParameters.myParam!}</div>

After the upgrade, I get this error when loading the template:

freemarker.core.InvalidReferenceException: The following has evaluated to null or missing:
==> RequestParameters  [in template "template.ftlh" at line 136, column 11]

----
Tip: If the failing expression is known to legally refer to something that's sometimes null or missing, either specify a default value like myOptionalVar!myDefault, or use <#if myOptionalVar??>when-present<#else>when-missing</#if>. (These only cover the last step of the expression; to cover the whole expression, use parenthesis: (myOptionalVar.foo)!myDefault, (myOptionalVar.foo)??
----

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FTL stack trace ("~" means nesting-related):
	- Failed at: ${RequestParameters.myParam!}  [in template "template.ftlh" at line 136, column 9]

It seems like RequestParameters is not available anymore.

I originally posted this issue in the spring-boot repo and @wilkinsona kindly pointed out that due to d84ca2b, there's no longer a RequestParameters entry in the model.

Are there plans to fix this?

Thanks!

[damir78]

Hello @anabright ,
Thank you.
I created an issue: #34637 but unfortunately it was closed.
The implementation of "RequestParameters" is https://github.com/apache/freemarker/blob/v2.3.32/src/main/java/freemarker/ext/servlet/HttpRequestHashModel.java and uses javax.* (for example javax.servlet) instead jakarta.* ( for example jakarta.servlet).

[Paul-Gerarts]

yes, I upgraded to SpringBoot 3.0.2 as parent and Freemarker had a hash for RequestParameters which doesn't exist anymore.

From the Freemarker docs:
"FreemarkerServlet also puts 3 hashes into the data-model, by which you can access the attributes of the 3 objects directly. The hash variables are: Request, Session, Application (corresponds to ServletContext). It also exposes another hash named RequestParameters that provides access to the parameters of the HTTP request."

Those RequestParameters could be accessed directly in your template, for example:
<input name="myParam" type="hidden" value="${RequestParameters.myParam!}"/>

As I'm working in a legacy project from waaaay back, I was hoping to find a more elegant way rather than getting the parameter from the servletRequest and adding it as an attribute to my model.

[mrhcongc]

I see that the issue is more than just not supporting the jakarta.*
The code in the FreeMarkerView.buildTemplateModel has been changed and has removed all the model additions.
I created my own implementations of a few classes to allow me to add the RequestParameters and Request back into the model.
If fixed in a future release, I'll just remove my classes.

[startjava]

use spring-boot 3.1.2

use url：
http://localhost:8080/test20?selectedValue=d

template code：
<#if listString?? && listString?size!=0> <#list listString as list> <#if RequestParameters['selectedValue']==list> ${list} </#if> <#if RequestParameters['selectedValue']!=list> ${list} </#if> </#list> </#if>

controller code：
@RequestMapping("test20")
public String test20(Model model,HttpServletRequest request,HttpServletResponse response)

{ List listString=new ArrayList(); listString.add("a"); listString.add("b"); listString.add("c"); listString.add("d"); listString.add("e"); request.setAttribute("listString",listString); return "test20"; }

run result ：
freemarker.core.InvalidReferenceException: The following has evaluated to null or missing:
==> RequestParameters [in template "test20.ftlh" at line 12, column 12]

Tip: If the failing expression is known to legally refer to something that's sometimes null or missing, either specify a default value like myOptionalVar!myDefault, or use <#if myOptionalVar??>when-present<#else>when-missing</#if>. (These only cover the last step of the expression; to cover the whole expression, use parenthesis: (myOptionalVar.foo)!myDefault, (myOptionalVar.foo)??

FTL stack trace ("~" means nesting-related):

• Failed at: #if RequestParameters.selectedValue =...

[in template "test20.ftlh" at line 12, column 7]

same question！

---

@anabright @mrhcongc @damir78 @Paul-Gerarts

[startjava]

spring-projects/spring-boot#34637

[startjava]

@wilkinsona

[snicoll]

@anabright unfortunately, there's nothing we can do here. Even the latest version of Freemarker does not use Jakarta as far as I can tell.

If you need to use the Servlet integration of Freemarker, only a change in freemarker can help here.