spring-framework / org.springframework.web.reactive.resource / VersionResourceResolver

VersionResourceResolver

open class VersionResourceResolver : AbstractResourceResolver

Resolves request paths containing a version string that can be used as part of an HTTP caching strategy in which a resource is cached with a date in the distant future (e.g. 1 year) and cached until the version, and therefore the URL, is changed.

Different versioning strategies exist, and this resolver must be configured with one or more such strategies along with path mappings to indicate which strategy applies to which resources.

ContentVersionStrategy is a good default choice except in cases where it cannot be used. Most notably the ContentVersionStrategy cannot be combined with JavaScript module loaders. For such cases the FixedVersionStrategy is a better choice.

Note that using this resolver to serve CSS files means that the CssLinkResourceTransformer should also be used in order to modify links within CSS files to also contain the appropriate versions generated by this resolver.

Author
Rossen Stoyanchev

Author
Brian Clozel

Since
5.0

See Also
VersionStrategy

Constructors

<init>

VersionResourceResolver()

Resolves request paths containing a version string that can be used as part of an HTTP caching strategy in which a resource is cached with a date in the distant future (e.g. 1 year) and cached until the version, and therefore the URL, is changed.

Different versioning strategies exist, and this resolver must be configured with one or more such strategies along with path mappings to indicate which strategy applies to which resources.

ContentVersionStrategy is a good default choice except in cases where it cannot be used. Most notably the ContentVersionStrategy cannot be combined with JavaScript module loaders. For such cases the FixedVersionStrategy is a better choice.

Note that using this resolver to serve CSS files means that the CssLinkResourceTransformer should also be used in order to modify links within CSS files to also contain the appropriate versions generated by this resolver.

Functions

addContentVersionStrategy

open fun addContentVersionStrategy(vararg pathPatterns: String): VersionResourceResolver

Insert a content-based version in resource URLs that match the given path patterns. The version is computed from the content of the file, e.g. "css/main-e36d2e05253c6c7085a91522ce43a0b4.css". This is a good default strategy to use except when it cannot be, for example when using JavaScript module loaders, use #addFixedVersionStrategy instead for serving JavaScript files.

addFixedVersionStrategy

open fun addFixedVersionStrategy(version: String, vararg pathPatterns: String): VersionResourceResolver

Insert a fixed, prefix-based version in resource URLs that match the given path patterns, for example: "{version}/js/main.js". This is useful (vs. content-based versions) when using JavaScript module loaders.

The version may be a random number, the current date, or a value fetched from a git commit sha, a property file, or environment variable and set with SpEL expressions in the configuration (e.g. see @Value in Java config).

If not done already, variants of the given pathPatterns, prefixed with the version will be also configured. For example, adding a "/js/**" path pattern will also cofigure automatically a "/v1.0.0/js/**" with "v1.0.0" the version String given as an argument.

addVersionStrategy

open fun addVersionStrategy(strategy: VersionStrategy, vararg pathPatterns: String): VersionResourceResolver

Register a custom VersionStrategy to apply to resource URLs that match the given path patterns.

getStrategyMap

open fun getStrategyMap(): MutableMap<String, VersionStrategy>

Return the map with version strategies keyed by path pattern.

setStrategyMap

open fun setStrategyMap(map: MutableMap<String, VersionStrategy>): Unit

Set a Map with URL paths as keys and VersionStrategy as values.

Supports direct URL matches and Ant-style pattern matches. For syntax details, see the AntPathMatcher javadoc.