LightPIT: src/main/kotlin/de/uapcore/lightpit/AbstractServlet.kt@1275eb652008 (annotated)

src/main/kotlin/de/uapcore/lightpit/AbstractServlet.kt@1275eb652008 (annotated)

src/main/kotlin/de/uapcore/lightpit/AbstractServlet.kt

Sat, 06 Jan 2024 20:31:14 +0100

author: Mike Becker <universe@uap-core.de>
date: Sat, 06 Jan 2024 20:31:14 +0100
changeset 298: 1275eb652008
parent 254: 55ca6cafc3dd
permissions: -rw-r--r--

add language selection cookie - fixes #352

 /*
  * Copyright 2021 Mike Becker. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
  *
  * 1. Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *
  * 2. Redistributions in binary form must reproduce the above copyright
  * notice, this list of conditions and the following disclaimer in the
  * documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 package de.uapcore.lightpit
 import de.uapcore.lightpit.DataSourceProvider.Companion.SC_ATTR_NAME
 import de.uapcore.lightpit.dao.DataAccessObject
 import de.uapcore.lightpit.dao.createDataAccessObject
 import jakarta.servlet.http.Cookie
 import jakarta.servlet.http.HttpServlet
 import jakarta.servlet.http.HttpServletRequest
 import jakarta.servlet.http.HttpServletResponse
 import java.sql.SQLException
 import java.util.*
 abstract class AbstractServlet : HttpServlet() {
     companion object {
         const val LANGUAGE_COOKIE_NAME = "lpit_language"
     }
     protected val logger = MyLogger()
     /**
      * Contains the GET request mappings.
      */
     private val getMappings = mutableMapOf<PathPattern, MappingMethod>()
     /**
      * Contains the POST request mappings.
      */
     private val postMappings = mutableMapOf<PathPattern, MappingMethod>()
     protected fun get(pattern: String, method: MappingMethod) {
         getMappings[PathPattern(pattern)] = method
     }
     protected fun post(pattern: String, method: MappingMethod) {
         postMappings[PathPattern(pattern)] = method
     }
     private fun notFound(http: HttpRequest, dao: DataAccessObject) {
         http.response.sendError(HttpServletResponse.SC_NOT_FOUND)
     }
     private fun findMapping(
         mappings: Map<PathPattern, MappingMethod>,
         req: HttpServletRequest
     ): Pair<PathPattern, MappingMethod> {
         val requestPath = sanitizedRequestPath(req)
         val candidates = mappings.filter { it.key.matches(requestPath) }
         return if (candidates.isEmpty()) {
             Pair(PathPattern(requestPath), ::notFound)
         } else {
             if (candidates.size > 1) {
                 logger.warn("Ambiguous mapping for request path '{0}'", requestPath)
             }
             candidates.entries.first().toPair()
         }
     }
     private fun invokeMapping(
         mapping: Pair<PathPattern, MappingMethod>,
         req: HttpServletRequest,
         resp: HttpServletResponse,
         dao: DataAccessObject
     ) {
         val params = mapping.first.obtainPathParameters(sanitizedRequestPath(req))
         val method = mapping.second
         logger.trace("invoke {0}", method)
         method(HttpRequest(req, resp, params), dao)
     }
     private fun sanitizedRequestPath(req: HttpServletRequest) = req.pathInfo ?: "/"
     private fun doProcess(
         req: HttpServletRequest,
         resp: HttpServletResponse,
         mappings: Map<PathPattern, MappingMethod>
     ) {
         val session = req.session
         // the very first thing to do is to force UTF-8
         req.characterEncoding = "UTF-8"
         // set some internal request attributes
         val http = HttpRequest(req, resp)
         val fullPath = req.servletPath + Optional.ofNullable(req.pathInfo).orElse("")
         req.setAttribute(Constants.REQ_ATTR_BASE_HREF, http.baseHref)
         req.setAttribute(Constants.REQ_ATTR_PATH, fullPath)
         req.getHeader("Referer")?.let {
             // TODO: add a sanity check to avoid link injection
             req.setAttribute(Constants.REQ_ATTR_REFERER, it)
         }
         // choose the requested language as session language (if available)
         if (session.getAttribute(Constants.SESSION_ATTR_LANGUAGE) == null) {
             // language selection stored in cookie
             val cookieLocale = cookieLanguage(http)
             // if no cookie, fall back to request locale a.k.a "Browser Language"
             val reqLocale = cookieLocale ?: req.locale
             val availableLanguages = availableLanguages()
             val sessionLocale = if (availableLanguages.contains(reqLocale)) reqLocale else availableLanguages.first()
             // select the language (this will also refresh the cookie max-age)
             selectLanguage(http, sessionLocale)
             logger.debug(
                 "Setting language for new session {0}: {1}", session.id, sessionLocale.displayLanguage
             )
         } else {
             val sessionLocale = session.getAttribute(Constants.SESSION_ATTR_LANGUAGE) as Locale
             resp.locale = sessionLocale
             logger.trace("Continuing session {0} with language {1}", session.id, sessionLocale)
         }
         // if this is an error path, bypass the normal flow
         if (fullPath.startsWith("/error/")) {
             http.styleSheets = listOf("error")
             http.render("error")
             return
         }
         // obtain a connection and create the data access objects
         val dsp = req.servletContext.getAttribute(SC_ATTR_NAME) as DataSourceProvider
         val dialect = dsp.dialect
         val ds = dsp.dataSource
         if (ds == null) {
             resp.sendError(
                 HttpServletResponse.SC_SERVICE_UNAVAILABLE,
                 "JNDI DataSource lookup failed. See log for details."
             )
             return
         }
         try {
             ds.connection.use { connection ->
                 val dao = createDataAccessObject(dialect, connection)
                 try {
                     connection.autoCommit = false
                     invokeMapping(findMapping(mappings, req), req, resp, dao)
                     connection.commit()
                 } catch (ex: SQLException) {
                     logger.warn("Database transaction failed (Code {0}): {1}", ex.errorCode, ex.message)
                     logger.debug("Details: ", ex)
                     resp.sendError(
                         HttpServletResponse.SC_INTERNAL_SERVER_ERROR,
                         "Unhandled Transaction Error - Code: " + ex.errorCode
                     )
                     connection.rollback()
                 }
             }
         } catch (ex: SQLException) {
             logger.error("Severe Database Exception (Code {0}): {1}", ex.errorCode, ex.message)
             logger.debug("Details: ", ex)
             resp.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR, "Database Error - Code: " + ex.errorCode)
         }
     }
     override fun doGet(req: HttpServletRequest, resp: HttpServletResponse) {
         doProcess(req, resp, getMappings)
     }
     override fun doPost(req: HttpServletRequest, resp: HttpServletResponse) {
         doProcess(req, resp, postMappings)
     }
     protected fun availableLanguages(): List<Locale> {
         val langTags = servletContext.getInitParameter(Constants.CTX_ATTR_LANGUAGES)?.split(",")?.map(String::trim) ?: emptyList()
         val locales = langTags.map(Locale::forLanguageTag).filter { it.language.isNotEmpty() }
         return locales.ifEmpty { listOf(Locale.ENGLISH) }
     }
     private fun cookieLanguage(http: HttpRequest): Locale? =
         http.request.cookies?.firstOrNull { c -> c.name == LANGUAGE_COOKIE_NAME }
             ?.runCatching {Locale.forLanguageTag(this.value)}?.getOrNull()
     protected fun selectLanguage(http: HttpRequest, locale: Locale) {
         http.response.locale = locale
         http.session.setAttribute(Constants.SESSION_ATTR_LANGUAGE, locale)
         // delete cookie if language selection matches request locale, otherwise set cookie
         val cookie = Cookie(LANGUAGE_COOKIE_NAME, "")
         cookie.isHttpOnly = true
         cookie.path = http.request.contextPath
         if (http.request.locale.language == locale.language) {
             cookie.maxAge = 0
         } else {
             cookie.value = locale.language
             cookie.maxAge = 2592000 // 30 days
         }
         http.response.addCookie(cookie)
     }
 }

Mercurial > hg > LightPIT / annotate

src/main/kotlin/de/uapcore/lightpit/AbstractServlet.kt@1275eb652008 (annotated)

src/main/kotlin/de/uapcore/lightpit/AbstractServlet.kt