org.springframework.web.reactive.resource

Class CssLinkResourceTransformer

java.lang.Object

org.springframework.web.reactive.resource.ResourceTransformerSupport

org.springframework.web.reactive.resource.CssLinkResourceTransformer

All Implemented Interfaces:

ResourceTransformer

public class CssLinkResourceTransformer
extends ResourceTransformerSupport

A ResourceTransformer implementation that modifies links in a CSS file to match the public URL paths that should be exposed to clients (e.g. with an MD5 content-based hash inserted in the URL).

The implementation looks for links in CSS @import statements and also inside CSS url() functions. All links are then passed through the ResourceResolverChain and resolved relative to the location of the containing CSS file. If successfully resolved, the link is modified, otherwise the original link is preserved.

Since:

5.0

Author:

Rossen Stoyanchev

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected static class	CssLinkResourceTransformer.AbstractLinkParser Abstract base class for CssLinkResourceTransformer.LinkParser implementations.
private static class	CssLinkResourceTransformer.ContentChunkInfo
private static class	CssLinkResourceTransformer.ImportLinkParser
protected static interface	CssLinkResourceTransformer.LinkParser Extract content chunks that represent links.
private static class	CssLinkResourceTransformer.UrlFunctionLinkParser

Field Summary

Fields

Modifier and Type	Field and Description
private static java.nio.charset.Charset	DEFAULT_CHARSET
private java.util.List<CssLinkResourceTransformer.LinkParser>	linkParsers
private static Log	logger

Constructor Summary

Constructors

Constructor and Description
CssLinkResourceTransformer()

Method Summary

Modifier and Type	Method and Description
private boolean	hasScheme(java.lang.String link)
private java.util.List<CssLinkResourceTransformer.ContentChunkInfo>	parseContent(java.lang.String cssContent)
<any>	transform(ServerWebExchange exchange, Resource inputResource, ResourceTransformerChain transformerChain) Transform the given resource.
private <any>	transformContent(java.lang.String cssContent, Resource resource, ResourceTransformerChain chain, ServerWebExchange exchange)

Methods inherited from class org.springframework.web.reactive.resource.ResourceTransformerSupport

getResourceUrlProvider, resolveUrlPath, setResourceUrlProvider, toAbsolutePath

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

DEFAULT_CHARSET

private static final java.nio.charset.Charset DEFAULT_CHARSET

logger

private static final Log logger

linkParsers

private final java.util.List<CssLinkResourceTransformer.LinkParser> linkParsers

Constructor Detail

CssLinkResourceTransformer

public CssLinkResourceTransformer()

Method Detail

transform

public <any> transform(ServerWebExchange exchange,
                       Resource inputResource,
                       ResourceTransformerChain transformerChain)

Description copied from interface: ResourceTransformer

Transform the given resource.

Parameters:

exchange - the current exchange

inputResource - the resource to transform

transformerChain - the chain of remaining transformers to delegate to

Returns:

the transformed resource (never empty)

transformContent

private <any> transformContent(java.lang.String cssContent,
                               Resource resource,
                               ResourceTransformerChain chain,
                               ServerWebExchange exchange)

parseContent

private java.util.List<CssLinkResourceTransformer.ContentChunkInfo> parseContent(java.lang.String cssContent)

hasScheme

private boolean hasScheme(java.lang.String link)