Master Spring Boot Static Resources: Paths, Custom Locations, and Cache Busting

Environment: Spring Boot 2.7.10

By default, Spring Boot serves static content from classpath locations /static , /public , /resources , or /META-INF/resources (or the servlet‑context root) using ResourceHttpRequestHandler . You can modify this behavior by adding a WebMvcConfigurer and overriding addResourceHandlers .

Static resources are mapped to /** by default, but the pattern can be changed with the spring.mvc.static-path-pattern property. For example, relocating all resources to /resources/** is possible.

Default static resource locations

<code>spring:
  web:
    resources:
      static-locations:
      - classpath:/META-INF/resources/
      - classpath:/resources/
      - classpath:/static/
      - classpath:/public/</code>

Directory structure illustration:

Default access URL: http://localhost:8080/xxx.yy

Modify access path

<code>spring:
  mvc:
    static-path-pattern: /res/**</code>

After modification, the URL becomes http://localhost:8080/res/xxx.yy .

Note: In older Spring Boot versions the property is spring.resources.static-locations .

Add custom static resource locations

<code>spring:
  web:
    resources:
      static-locations:
      - classpath:/META-INF/resources/
      - classpath:/resources/
      - classpath:/static/
      - classpath:/public/
      - file:///D:/images/</code>

The file:///D:/images/ entry points to a custom file‑system directory (three slashes are required).

Programmatic configuration

<code>@Configuration
public class WebConfig implements WebMvcConfigurer {
    @Override
    public void addResourceHandlers(ResourceHandlerRegistry registry) {
        registry.addResourceHandler("/static/**")
                .addResourceLocations("file:///d:/images/");
        registry.addResourceHandler("/h5/**")
                .addResourceLocations("file:///d:/h5/");
    }
}</code>

These handlers expose the two file‑system directories at /static/** and /h5/** . Access via http://localhost:8080/static/xxx.yy and http://localhost:8080/h5/xxx .

WebJars static resources

Resources under /webjars/** are served from JAR files that contain WebJars‑packaged assets.

If your application is packaged as a JAR, do not use src/main/webapp ; that directory is only for WAR packaging.

Spring Boot also supports advanced resource handling such as cache busting and version‑agnostic URLs for WebJars. Adding webjars-locator-core enables version‑agnostic URLs, e.g., /webjars/jquery/jquery.min.js becomes /webjars/jquery/3.6.0/jquery.min.js .

Cache busting configuration

<code>spring:
  web:
    resources:
      chain:
        strategy:
          content:
            enabled: true
            paths: "/**"</code>

Static resource handling internals

Spring MVC creates a ResourceHandlerRegistry bean in WebMvcConfigurationSupport . The registry registers ResourceHandlerRegistration objects, which are turned into ResourceHttpRequestHandler instances and mapped via SimpleUrlHandlerMapping . The HttpRequestHandlerAdapter adapts these handlers for the MVC dispatch chain.

Key source code snippets illustrate the creation of the registry, conversion to handlers, and registration of the HandlerMapping .