org.springframework.web.reactive.resource

Class AppCacheManifestTransformer

java.lang.Object

org.springframework.web.reactive.resource.ResourceTransformerSupport

org.springframework.web.reactive.resource.AppCacheManifestTransformer

All Implemented Interfaces:

ResourceTransformer

public class AppCacheManifestTransformer
extends ResourceTransformerSupport

A ResourceTransformer HTML5 AppCache manifests.

This transformer:

• modifies links to match the public URL paths that should be exposed to clients, using configured ResourceResolver strategies
• appends a comment in the manifest, containing a Hash (e.g. "# Hash: 9de0f09ed7caf84e885f1f0f11c7e326"), thus changing the content of the manifest in order to trigger an appcache reload in the browser.

All files with an ".appcache" file extension (or the extension given to the constructor) will be transformed by this class. The hash is computed using the content of the appcache manifest so that changes in the manifest should invalidate the browser cache. This should also work with changes in referenced resources whose links are also versioned.

Since:

5.0

Author:

Rossen Stoyanchev, Brian Clozel

See Also:

HTML5 offline applications spec

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
private static class	AppCacheManifestTransformer.LineInfo
private static class	AppCacheManifestTransformer.LineInfoGenerator

Field Summary

Fields

Modifier and Type	Field and Description
private static java.lang.String	CACHE_HEADER
private static java.nio.charset.Charset	DEFAULT_CHARSET
private java.lang.String	fileExtension
private static Log	logger
private static java.lang.String	MANIFEST_HEADER
private static java.util.Collection<java.lang.String>	MANIFEST_SECTION_HEADERS

Constructor Summary

Constructors

Constructor and Description
AppCacheManifestTransformer() Create an AppCacheResourceTransformer that transforms files with extension ".appcache".
AppCacheManifestTransformer(java.lang.String fileExtension) Create an AppCacheResourceTransformer that transforms files with the extension given as a parameter.

Method Summary

Modifier and Type	Method and Description
private <any>	processLine(AppCacheManifestTransformer.LineInfo info, ServerWebExchange exchange, Resource resource, ResourceTransformerChain chain)
<any>	transform(ServerWebExchange exchange, Resource inputResource, ResourceTransformerChain chain) Transform the given resource.
private <any>	transform(java.lang.String content, Resource resource, ResourceTransformerChain chain, ServerWebExchange exchange)
private static void	writeToByteArrayOutputStream(java.io.ByteArrayOutputStream out, java.lang.String toWrite)

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

MANIFEST_SECTION_HEADERS

private static final java.util.Collection<java.lang.String> MANIFEST_SECTION_HEADERS

MANIFEST_HEADER

private static final java.lang.String MANIFEST_HEADER

See Also:

Constant Field Values

CACHE_HEADER

private static final java.lang.String CACHE_HEADER

See Also:

Constant Field Values

DEFAULT_CHARSET

private static final java.nio.charset.Charset DEFAULT_CHARSET

logger

private static final Log logger

fileExtension

private final java.lang.String fileExtension

Constructor Detail

AppCacheManifestTransformer

public AppCacheManifestTransformer()

Create an AppCacheResourceTransformer that transforms files with extension ".appcache".

AppCacheManifestTransformer

public AppCacheManifestTransformer(java.lang.String fileExtension)

Create an AppCacheResourceTransformer that transforms files with the extension given as a parameter.

Method Detail

transform

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

Description copied from interface: ResourceTransformer

Transform the given resource.

Parameters:

exchange - the current exchange

inputResource - the resource to transform

chain - the chain of remaining transformers to delegate to

Returns:

the transformed resource (never empty)

transform

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

writeToByteArrayOutputStream

private static void writeToByteArrayOutputStream(java.io.ByteArrayOutputStream out,
                                                 java.lang.String toWrite)

processLine

private <any> processLine(AppCacheManifestTransformer.LineInfo info,
                          ServerWebExchange exchange,
                          Resource resource,
                          ResourceTransformerChain chain)