org.springframework.web.servlet.resource

Class CssLinkResourceTransformer

java.lang.Object

org.springframework.web.servlet.resource.ResourceTransformerSupport

org.springframework.web.servlet.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:

4.1

Author:

Rossen Stoyanchev

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected static class	CssLinkResourceTransformer.AbstractCssLinkParser
private static class	CssLinkResourceTransformer.CssLinkInfo
protected static interface	CssLinkResourceTransformer.CssLinkParser
private static class	CssLinkResourceTransformer.ImportStatementCssLinkParser
private static class	CssLinkResourceTransformer.UrlFunctionCssLinkParser

Field Summary

Fields

Modifier and Type	Field and Description
private static java.nio.charset.Charset	DEFAULT_CHARSET
private java.util.List<CssLinkResourceTransformer.CssLinkParser>	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)
Resource	transform(HttpServletRequest request, Resource resource, ResourceTransformerChain transformerChain) Transform the given resource.

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

getResourceUrlProvider, resolveUrlPath, setResourceUrlProvider

Methods inherited from class java.lang.Object

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

Field Detail

logger

private static final Log logger

DEFAULT_CHARSET

private static final java.nio.charset.Charset DEFAULT_CHARSET

linkParsers

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

Constructor Detail

CssLinkResourceTransformer

public CssLinkResourceTransformer()

Method Detail

transform

public Resource transform(HttpServletRequest request,
                          Resource resource,
                          ResourceTransformerChain transformerChain)
                   throws java.io.IOException

Description copied from interface: ResourceTransformer

Transform the given resource.

Parameters:

request - the current request

resource - the resource to transform

transformerChain - the chain of remaining transformers to delegate to

Returns:

the transformed resource, never null

Throws:

java.io.IOException - if the transformation fails

hasScheme

private boolean hasScheme(java.lang.String link)