eu.europeana.api2.v2.utils

Class HttpCacheUtils

java.lang.Object

eu.europeana.api2.v2.utils.HttpCacheUtils

public class HttpCacheUtils
extends Object

Utility class for http caching functionality

Author:

Maike, integrated with similar class created for IIIF API by:, Patrick Ehlert (03-10-2018) Created on 10-10-18.

Field Summary

Fields

Modifier and Type	Field and Description
static String	IFMATCH
static String	IFNONEMATCH

Constructor Summary

Constructors

Constructor and Description
HttpCacheUtils()

Method Summary

Modifier and Type	Method and Description
javax.servlet.http.HttpServletResponse	addDefaultHeaders(javax.servlet.http.HttpServletResponse response, String eTag, String tsUpdated) Generate the default headers for sending a response with caching The 'Cache-Control' and 'Allow' headers are always set to the same value
String	dateToRFC1123String(Date date) Formats the given java.util.Date according to the RFC 1123 pattern (e.g.
boolean	doesAnyIfNoneMatch(javax.servlet.http.HttpServletRequest request, String eTag) Supports multiple values in the "If-None-Match" header
boolean	doesPreconditionFail(javax.servlet.http.HttpServletRequest request, String eTag) Supports multiple values in the "If-Match" header
String	generateETag(String data, boolean weakETag, boolean includeApiVersion) Generates an eTag surrounded with double quotes
boolean	isModifiedSince(javax.servlet.http.HttpServletRequest request, Date tsUpdated) Deprecated.
boolean	isNotModifiedSince(javax.servlet.http.HttpServletRequest request, Date tsUpdated)

Methods inherited from class java.lang.Object

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

Field Detail

IFNONEMATCH

public static final String IFNONEMATCH

See Also:

Constant Field Values

IFMATCH

public static final String IFMATCH

See Also:

Constant Field Values

Constructor Detail

HttpCacheUtils

public HttpCacheUtils()

Method Detail

generateETag

public String generateETag(String data,
                           boolean weakETag,
                           boolean includeApiVersion)

Generates an eTag surrounded with double quotes

Parameters:

data -

weakETag - if true then the eTag will start with W/

includeApiVersion - if true then the API_version will be included in the ETag calculation (this is recommended when calculating weak ETags) *

Returns:

dateToRFC1123String

public String dateToRFC1123String(Date date)

Formats the given java.util.Date according to the RFC 1123 pattern (e.g. Thu, 4 Oct 2018 10:34:20 GMT)

Parameters:

date - Date object to be formatted

Returns:

RFC 1123 patterned String representation

addDefaultHeaders

public javax.servlet.http.HttpServletResponse addDefaultHeaders(javax.servlet.http.HttpServletResponse response,
                                                                String eTag,
                                                                String tsUpdated)

Generate the default headers for sending a response with caching The 'Cache-Control' and 'Allow' headers are always set to the same value

Parameters:

response - required, HttpServletResponse to add the headers to

eTag - optional, if not null then an ETag header is added

tsUpdated - optional, if not null then a Last-Modified header is added

Returns:

HttpServletResponse

doesAnyIfNoneMatch

public boolean doesAnyIfNoneMatch(javax.servlet.http.HttpServletRequest request,
                                  String eTag)

Supports multiple values in the "If-None-Match" header

Parameters:

request - incoming HttpServletRequest

eTag - String with the calculated eTag of the requested data

Returns:

boolean true IF ( If-None-Match header is supplied AND ( contains matching eTag OR == "*" ) ) Otherwise false

isNotModifiedSince

public boolean isNotModifiedSince(javax.servlet.http.HttpServletRequest request,
                                  Date tsUpdated)

Parameters:

request - incoming HttpServletRequest

tsUpdated - Date representing the FullBean's timestamp_updated

Returns:

boolean true IF If-Modified-Since header is supplied AND is after or on the timestamp_updated Otherwise false

isModifiedSince

@Deprecated
public boolean isModifiedSince(javax.servlet.http.HttpServletRequest request,
                                           Date tsUpdated)

Deprecated.

Parameters:

request - incoming HttpServletRequest

tsUpdated - Date representing the FullBean's timestamp_updated

Returns:

boolean true IF If-Modified-Since header is supplied AND is earlier the timestamp_updated Otherwise false NOTE this method was used for implementing the If-Modified-Since exception on the If-None-Match header processing specified in RFC 2616. It turns out that this RFC is obsolete and superseded by RFC 7232, which simply states to ignore the If-Modified-Since when If-None-Match is available (and can be handled)

doesPreconditionFail

public boolean doesPreconditionFail(javax.servlet.http.HttpServletRequest request,
                                    String eTag)

Supports multiple values in the "If-Match" header

Parameters:

request - incoming HttpServletRequest

eTag - String with the calculated eTag of the requested data

Returns:

boolean true IF ("If-Match" header is supplied AND NOT (contains matching eTag OR == "*") ) otherwise false