0
votes

I am trying to load some Freemarker templating from the DB using stringLoader and executing them through template.process, but here is the problem, freemarker stuff like <#if... is executing but when I try to execute assign JspTaglibs it breaks.

Here is a simple example:

From the DB I get <#assign bean=JspTaglibs["/WEB-INF/struts-bean.tld]>, which i put in a in StringTemplateLoader. I create configuration, template.. so far everything is working. When I do template.process(data, out), the page reports:

Starting output:FreeMarker template error: The following has evaluated to null or missing: ==> JspTaglibs [in template "temp" at line 1, column 15] Tip: If the failing expression is known to be legally null/missing, either specify a default value with myOptionalVar!myDefault, or use <#if myOptionalVar??>when-present<#else>when-missing. (These only cover the last step of the expression; to cover the whole expression, use parenthessis: (myOptionVar.foo)!myDefault, (myOptionVar.foo)?? The failing instruction (FTL stack trace): ---------- ==> #assign bean = JspTaglibs["/WEB-INF/s... [in template "temp" at line 1, column 1] ---------- Java stack trace (for programmers): ---------- freemarker.core.InvalidReferenceException: [... Exception message was already printed; see it above ...] at freemarker.core.InvalidReferenceException.getInstance(InvalidReferenceException.java:98) at freemarker.core.DynamicKeyName._eval(DynamicKeyName.java:87) at freemarker.core.Expression.eval(Expression.java:111) at freemarker.core.Assignment.accept(Assignment.java:106) at freemarker.core.Environment.visit(Environment.java:265) at freemarker.core.Environment.process(Environment.java:243) at freemarker.template.Template.process(Template.java:277) at org.apache.jsp.test5_jsp._jspService(test5_jsp.java:109) at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70) at javax.servlet.http.HttpServlet.service(HttpServlet.java:727) at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:432) at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:390) at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:334) at javax.servlet.http.HttpServlet.service(HttpServlet.java:727) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122) at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:501) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103) at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:950) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408) at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1070) at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:611) at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.doRun(AprEndpoint.java:2440) at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.run(AprEndpoint.java:2429) at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) at java.lang.Thread.run(Unknown Source)

Scenario that I have is that I have some code stored in the database and I would like to execute it by freemarker during template.process(). Is that even possible, and if it is, what am I doing wrong?

1

1 Answers

0
votes

The problem is that JspTaglibs is not a core FreeMarker feature, but something that the FreemarkerServlet puts into the data-model, and something that requires Servlet environment and a HTTP request (as JSP requires that). Out of the box, there's no way to separate this feature from the FreemarkerServlet. However, maybe you can extend it so that you can still use it for your purpose. Most of the magic happens inside createModel, where among others, it adds JspTaglibs to the data-model.

It might also useful to know that FreeMarker (and thus FreemarkerServlet) can load templates directly from the database, if you give it a such TemplateLoader implementation through the FreeMarker Configuration. If all you want is serving templates from the database instead of where Struts traditionally stores them, you just need to provide the proper TemplateLoader.