How can I use SSI with spring-boot?

Question

I have a simple "single" page app with a lot of JavaScript and jQueryUI Dialogs. I am using spring-boot for the REST API and currently deliver the *.html page(s) from the /resources/public folder. I now wanted to extract the jQueryUI Dialog divs into separate files to make the code cleaner, but I didn't find an easy way to just have them as server side includes. I was hoping to just use the embedded tomcat directives for SSI: https://tomcat.apache.org/tomcat-7.0-doc/ssi-howto.html But this doesn't seem to get evaluated. Do I miss some configuration in the application.properties or is there another easy way to achieve this?

Answer 1

The answer from rich p reminded me of this old question and as I found an alternate solution I decided to add this as an answer in case anyone else has a similar question:

One way I found is to use thymeleaf or more precise their page layouts. With this I can define snippets in separate HTML files and add the th:fragment attribute. These can then be included in other files with th:insert or th:replace. Check the second link for examples on how to use it.

Answer 2

( Grant you this is an ancient question... )

Perhaps you can register the Tomcat filter (SSIFilter) using one of the suggestions on this other SO page. For example, Haim's (approved) solution included registering a filter with code like that below. The only bit I didn't see right away, relevant to your use case, was how to configure the SSIFilter :)

The code below is conjecture - I didn't actually try it. I've been investigating whether it was possible to do what you're asking about, as a risk-assessment question. I'm interested - Did you actually pull this off? Has anyone?

    import org.apache.catalina.ssi.SSIFilter;

    @Bean
    public FilterRegistrationBean someFilterRegistration() {

        FilterRegistrationBean registration = new FilterRegistrationBean();
        registration.setFilter(someFilter());
        registration.addUrlPatterns("/url/*");
        registration.addInitParameter("paramName", "paramValue");
        registration.setName("someFilter");
        registration.setOrder(1);
        return registration;
    } 

    public Filter someFilter() {
        // SSIFilter filt = new SSIFilter();
        // ..create and configure the  new SSIFilter() ...

        Filter filt = new SSIFilter() {
            public void reconfigure( FilterConfig config ) {
                this.config = config;

                // reconfigure only what you care about
                this.allowExec = config.allowExec;
                this.contentTypeRexEx = config.contentTypeRegEx;
                this.debug = config.debug;
                this.expires = config.expires;
                this.isVirtualWebappRelative = config.isVirtualWebappRelative;
            }
        };

        /*
            From:  https://tomcat.apache.org/tomcat-7.0-doc/ssi-howto.html 

            contentType - A regex pattern that must be matched before SSI processing is applied.
                When crafting your own pattern, don't forget that a mime content type
                may be followed by an optional character set in the form "mime/type;
                charset=set" that you must take into account. Default is
                "text/x-server-parsed-html(;.*)?".
            debug - Debugging detail level for messages logged by this servlet. Default 0.
            expires - The number of seconds before a page with SSI directives will expire.
                Default behaviour is for all SSI directives to be evaluated for every request.
            isVirtualWebappRelative - Should "virtual" SSI directive paths be interpreted
                as relative to the context root, instead of the server root? Default false.
            allowExec - Is the exec command enabled? Default is false.
         */

        FilterConfig fcfg = new FilterConfig() {
            public FilterConfig withChanges( boolean allowExec, Pattern contentTypeRegEx, int debug, Long expires, boolean isVirtualWebappRelative ) {
                this.allowExec = allowExec;
                this.contentTypeRegEx = contentTypeRegEx;
                this.debug = debug;
                this.expires = expires;
                this.isVirtualWebappRelative = isVirtualWebappRelative;
            }
        };

        filt.reconfigure(
            fcfg.withChanges(
                false,
                "text/x-server-partsed-html(;.*)?",
                java.util.logging.Level.FINEST.intValue(),
                (Instant.now().getEpochSecond() + (24*60*60)),
                false
            )
        );

        // ok hopefully that configured it!
        return filt;
    }