velosurf.web.l10n
Class LocalizationFilter

java.lang.Object
  velosurf.web.l10n.LocalizationFilter

All Implemented Interfaces:

javax.servlet.Filter

public class LocalizationFilter
extends java.lang.Object
implements javax.servlet.Filter

Localization filter. It's goal is to redirect or forward incoming unlocalized http requests (depending on the choosen method, FORWARD or REDIRECT) towards an address taking into account the best match between requested locales and supported locales, and also to deduce the locale from URLS (when REDIRECT is used).

Optional init parameters:

• supported-locales: comma separated list of supported locales ; if not provided, there is an attempt to programatically determine it⁽¹⁾. No default value provided.
• default-locale: the locale to be used by default (after four checks: the incoming URI, the session, cookies, and the request headers). No default value provided.
• localization-method: forward or redirect, default is redirect.
• match-host & rewrite-host: not yet implemented.⁽²⁾
• match-uri & rewrite-uri: the regular expression against which an unlocalized uri is matched, and the replacement uri, where @ represents the locale and $1, $2, ... the matched sub-patterns. Defaults are ^/(.*)$ for match-uri and /@/$1 for rewrite-uri.(2)
• match-query-string & rewrite-query-string: not yet implemented.(2)
• match-url & rewrite-url: not yet implemented.(2)

(1) for now, to find supported locales if this parameter is not provided, the filter try to use the rewrite-uri param and to check for the existence of corresponding directories (only if the rewriting string contains a pattern like '/@/', that is if you use directories to store localized sites).

(2) The different match- and rewrite- parameters pairs are mutually exclusive. All matches are case-insensitive. When using the redirect method, POST parameters are lost.

When the REDIRECT method is used, these supplementary parameters (mutually exclusive) allow the filter to know whether or not an incoming URI is localized.

• inspect-host: not yet implemented.
• inspect-uri: default is ^/(.+)(?:/|$).
• inspect-query-string: not yet implemented.
• inspect-url: not yet implemented.

Author:

Claude Brisson

Field Summary

private javax.servlet.FilterConfig	_config
private static java.lang.String	_defaultInspectUri
private java.util.Locale	_defaultLocale
private static java.lang.String	_defaultMatchUri
private static java.lang.String	_defaultRewriteUri
private java.util.regex.Pattern	_inspectUri
private int	_l10nMethod
private java.util.regex.Pattern	_matchUri
private java.lang.String	_rewriteUri
private java.util.List<java.util.Locale>	_supportedLocales
private static int	FORWARD
private static int	REDIRECT
private static int	SECONDS_IN_YEAR

Constructor Summary

LocalizationFilter()

Method Summary

void	destroy()
void	doFilter(javax.servlet.ServletRequest servletRequest, javax.servlet.ServletResponse servletResponse, javax.servlet.FilterChain chain)
private void	findSupportedLocales(javax.servlet.FilterConfig config)
private java.lang.String	getInitParameter(java.lang.String key)
private java.lang.String	getInitParameter(java.lang.String key, java.lang.String defaultValue)
private java.util.Locale	getMatchedLocale(java.lang.String candidate)
private java.util.Locale	getPreferredLocale(java.util.List<java.util.Locale> requestedLocales)
private java.util.List<java.util.Locale>	getRequestedLocales(javax.servlet.http.HttpServletRequest request)
private java.util.List<java.util.Locale>	guessSupportedLocales(javax.servlet.ServletContext ctx, java.lang.String path)
void	init(javax.servlet.FilterConfig config)

Methods inherited from class java.lang.Object

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

Field Detail

_config

private javax.servlet.FilterConfig _config

_supportedLocales

private java.util.List<java.util.Locale> _supportedLocales

_defaultLocale

private java.util.Locale _defaultLocale

SECONDS_IN_YEAR

private static int SECONDS_IN_YEAR

_defaultMatchUri

private static java.lang.String _defaultMatchUri

_defaultRewriteUri

private static java.lang.String _defaultRewriteUri

_defaultInspectUri

private static java.lang.String _defaultInspectUri

_matchUri

private java.util.regex.Pattern _matchUri

_rewriteUri

private java.lang.String _rewriteUri

_inspectUri

private java.util.regex.Pattern _inspectUri

FORWARD

private static final int FORWARD

See Also:

Constant Field Values

REDIRECT

private static final int REDIRECT

See Also:

Constant Field Values

_l10nMethod

private int _l10nMethod

Constructor Detail

LocalizationFilter

public LocalizationFilter()

Method Detail

init

public void init(javax.servlet.FilterConfig config)
          throws javax.servlet.ServletException

Specified by:

init in interface javax.servlet.Filter

Throws:

javax.servlet.ServletException

doFilter

public void doFilter(javax.servlet.ServletRequest servletRequest,
                     javax.servlet.ServletResponse servletResponse,
                     javax.servlet.FilterChain chain)
              throws java.io.IOException,
                     javax.servlet.ServletException

Specified by:

doFilter in interface javax.servlet.Filter

Throws:

java.io.IOException

javax.servlet.ServletException

findSupportedLocales

private void findSupportedLocales(javax.servlet.FilterConfig config)

getInitParameter

private java.lang.String getInitParameter(java.lang.String key)

getInitParameter

private java.lang.String getInitParameter(java.lang.String key,
                                          java.lang.String defaultValue)

destroy

public void destroy()

Specified by:

destroy in interface javax.servlet.Filter

guessSupportedLocales

private java.util.List<java.util.Locale> guessSupportedLocales(javax.servlet.ServletContext ctx,
                                                               java.lang.String path)

getRequestedLocales

private java.util.List<java.util.Locale> getRequestedLocales(javax.servlet.http.HttpServletRequest request)

getMatchedLocale

private java.util.Locale getMatchedLocale(java.lang.String candidate)

getPreferredLocale

private java.util.Locale getPreferredLocale(java.util.List<java.util.Locale> requestedLocales)