Default Spring Boot Thymeleaf configuration location

I've used JSP for eons, but only now am I trying out Thymeleaf. I've found that for my application I need to add some adjustments to my application.properties file, and I've figured out the Spring Boot Thymeleaf settings to use.

But where can I find the authoritative, complete list of Thymeleaf settings Spring Boot uses by default? For example, I know that Spring Boot configures Thymeleaf to look in the /templates/ directory on the classpath for templates, and I know how to change that. But where is the default /templates/ configured? Is there a DefaultXXX class or a .properties file I can open to see how these are set and what values are used if I make no changes?

There is a list of properties settings here - you can search that page for "thymeleaf" to find the relevant section.

Example:

Key                      Default Value          Description
spring.thymeleaf.prefix  classpath:/templates/  Prefix that gets prepended to view names when building a URL.

This example shows that for the Thymeleaf ClassLoaderTemplateResolver a default value of /templates/ is used (as you noted).

I don't know if it's The Authoritative, Complete List - but it looks to be reasonably comprehensive, based on the settings I would normally expect to be setting in a non-Spring Thymeleaf implementation.

Update

To add some more details, looking at two examples in the documentation:

Example 1: spring.thymeleaf.cache - defaults to true

For this value, the default is defined in the AbstractConfigurableTemplateResolver class:

public static final boolean DEFAULT_CACHEABLE = true;

Here is a link to the source code on GitHub.

Example 2: spring.thymeleaf.prefix - defaults to classpath:/templates/

In this case, there is a Spring class which handles this (and many other) defaults: org.springframework.boot.autoconfigure.thymeleaf.ThymeleafProperties

It's probably easiest just to jump straight to the source and look at the defaults set there.

For example the prefix example:

public static final String DEFAULT_PREFIX = "classpath:/templates/";

It's also worth noting that the cache setting from example 1 above is also explicitly set in the Spring ThymeleafProperties class.

Additional Notes

There are also properties for reactive settings:

spring.thymeleaf.reactive.max-chunk-size - default is 0B

This is set in a nested Reactive class:

private DataSize maxChunkSize = DataSize.ofBytes(0);

The above locations are still not 100% comprehensive. For example:

spring.thymeleaf.enable-spring-el-compiler is set to false according to the documentation. And in the source code it is implicitly false:

private boolean enableSpringElCompiler;

But that does not tell you what possible compiler settings can be, if you choose to set this property to true (see here).

A Note on Properties Files

I am not aware of any default properties file or properties file template which is used as a part of this Thymeleaf configuration process. My understanding is that if you want to customize these settings, and you do not already have a Spring properties file, you have to create it yourself - but I may be mistaken.

Additional Notes 2

Taking the example of the DEFAULT_PREFIX: This is handled by the ThymeleafAutoConfiguration class (here). This sets the prefix in the SpringResourceTemplateResolver class, which is part of Thymeleaf's Spring integration module (source here).

resolver.setPrefix(this.properties.getPrefix());

This resolver "resolves templates using Spring's Resource Resolution mechanism" - which is where my research stalls.

Regarding the relationship between the default prefix and the value provided by spring.thymeleaf.prefix, the only location where I see a direct connection is here, which calls a PropertyResolver method to return the user-provided property value, or else the default value, otherwise. But again, this is only for verifying that a template can be located (rather than actually being retrieved) - so that is certainly not the full picture. Again, this is where my research stalls.