use HashMap insted of ArrayList to store the timetables

src/main/kotlin/org/mosad/thecitadelofricks/DataTypes.kt

@@ -29,9 +29,9 @@ import kotlin.collections.HashMap
 // data classes for the course part
 data class Course(val courseName: String, val courseLink: String)
 
-data class CoursesMeta(val updateTime: Long, val totalCourses: Int)
+data class CoursesMeta(val updateTime: Long = 0, val totalCourses: Int = 0)
 
-data class CoursesList(val meta: CoursesMeta, val courses: ArrayList<Course>)
+data class CoursesList(val meta: CoursesMeta = CoursesMeta(), val courses: HashMap<String, Course> = HashMap())
 
 // data classes for the Mensa part
 data class Meal(val day: String, val heading: String, val parts: ArrayList<String>, val additives: String)

src/main/kotlin/org/mosad/thecitadelofricks/controller/CacheController.kt

@@ -23,10 +23,7 @@
 package org.mosad.thecitadelofricks.controller
 
 import com.google.gson.Gson
-import kotlinx.coroutines.GlobalScope
-import kotlinx.coroutines.async
-import kotlinx.coroutines.launch
-import kotlinx.coroutines.runBlocking
+import kotlinx.coroutines.*
 import org.mosad.thecitadelofricks.*
 import org.mosad.thecitadelofricks.hsoparser.CourseListParser
 import org.mosad.thecitadelofricks.hsoparser.MensaParser
@@ -39,6 +36,7 @@ import java.io.FileWriter
 import java.util.*
 import java.util.concurrent.Executors
 import kotlin.collections.ArrayList
+import kotlin.collections.HashMap
 import kotlin.collections.HashSet
 import kotlin.concurrent.scheduleAtFixedRate
 
@@ -52,9 +50,9 @@ class CacheController {
     companion object{
         private val logger: Logger = LoggerFactory.getLogger(CacheController::class.java)
 
-        var courseList = CoursesList(CoursesMeta(0, 0), ArrayList())
+        var courseList = CoursesList()
         var mensaMenu = MensaMenu(MensaMeta(0,""), MensaWeek(), MensaWeek())
-        var timetableList = ArrayList<TimetableCourseWeek>() // this list contains all timetables
+        var timetableList = HashMap<String, TimetableCourseWeek>() // this list contains all timetables
 
         /**
          * get a timetable, since they may not be cached, we need to make sure it's cached, otherwise download
@@ -63,30 +61,22 @@ class CacheController {
          * @return timetable of the course (Type: [TimetableCourseWeek])
          */
         fun getTimetable(courseName: String, weekIndex: Int): TimetableCourseWeek = runBlocking {
-            val currentTime = System.currentTimeMillis() / 1000
-            var timetable = TimetableWeek()
-            var weekNumberYear = 0
-
-            // check if the timetable already exists and is up to date
-            when (timetableList.stream().filter { x -> x.meta.courseName == courseName && x.meta.weekIndex == weekIndex }.findAny().orElse(null)) {
-                // there is no such course yet, create one
-                null -> {
-                    val courseLink = courseList.courses.stream().filter { x -> x.courseName == courseName }.findFirst().orElse(null).courseLink
-                    val timetableLink = courseLink.replace("week=0","week=$weekIndex")
-
-                    val jobTimetable = async {
-                        timetable = TimetableParser().getTimeTable(timetableLink)
-                        weekNumberYear = TimetableParser().getWeekNumberYear(timetableLink)
-                    }
-
-                    jobTimetable.await()
-                    timetableList.add(TimetableCourseWeek(TimetableCourseMeta(currentTime, courseName, weekIndex, weekNumberYear, timetableLink), timetable))
-
-                    logger.info("added new timetable for $courseName, week $weekIndex")
-                }
+            return@runBlocking timetableList.getOrPut("$courseName-$weekIndex") {
+                val timetableLink = courseList.courses[courseName]
+                    ?.courseLink
+                    ?.replace("week=0", "week=$weekIndex") ?: ""
+                val currentTime = System.currentTimeMillis() / 1000
+                var timetable = TimetableWeek()
+                var weekNumberYear = 0
+
+                val timetableJobs = listOf(
+                    async { timetable = TimetableParser().getTimeTable(timetableLink) },
+                    async { weekNumberYear = TimetableParser().getWeekNumberYear(timetableLink) }
+                )
+
+                timetableJobs.awaitAll()
+                TimetableCourseWeek(TimetableCourseMeta(currentTime, courseName, weekIndex, weekNumberYear, timetableLink), timetable)
             }
-
-            return@runBlocking timetableList.stream().filter { x -> x.meta.courseName == courseName && x.meta.weekIndex == weekIndex }.findAny().orElse(null)
         }
 
         /**
@@ -170,10 +160,10 @@ class CacheController {
             try {
                 timetableList.forEach { timetableCourse ->
                     executor.execute {
-                        timetableCourse.timetable = TimetableParser().getTimeTable(timetableCourse.meta.link)
-                        timetableCourse.meta.updateTime = System.currentTimeMillis() / 1000
+                        timetableCourse.value.timetable = TimetableParser().getTimeTable(timetableCourse.value.meta.link)
+                        timetableCourse.value.meta.updateTime = System.currentTimeMillis() / 1000
 
-                        saveTimetableToCache(timetableCourse) // save the updated timetable to the cache directory
+                        saveTimetableToCache(timetableCourse.value) // save the updated timetable to the cache directory
                     }
 
                 }

src/main/kotlin/org/mosad/thecitadelofricks/controller/StartupController.kt

@@ -134,7 +134,8 @@ class StartupController {
 
                 try {
                     val timetableObject = JsonParser.parseString(bufferedReader.readLine()).asJsonObject
-                    CacheController.timetableList.add(Gson().fromJson(timetableObject, TimetableCourseWeek().javaClass))
+                    val timetable = Gson().fromJson(timetableObject, TimetableCourseWeek().javaClass)
+                    CacheController.timetableList.put("${timetable.meta.courseName}-${timetable.meta.weekIndex}", timetable)
                 } catch (ex: Exception) {
                     logger.error("error while reading cache", ex)
                 } finally {

src/main/kotlin/org/mosad/thecitadelofricks/hsoparser/CourseListParser.kt

@@ -36,17 +36,15 @@ class CourseListParser {
      * @param courseListURL the url to the course list page
      * @return a ArrayList<Course> with all courses or null if the request was not successful
      */
-    fun getCourseLinks(courseListURL: String): ArrayList<Course>? {
-        val courseLinkList = ArrayList<Course>()
+    fun getCourseLinks(courseListURL: String): HashMap<String, Course>? {
+        val courseLinkList = HashMap<String, Course>()
         try {
             val courseHTML = Jsoup.connect(courseListURL).get()
 
             courseHTML.select("ul.index-group").select("li.Class").select("a[href]").forEachIndexed { _, element ->
-                courseLinkList.add(
-                    Course(
-                        element.text(),
-                        element.attr("href").replace("http", "https")
-                    )
+                courseLinkList[element.text()] = Course(
+                    element.text(),
+                    element.attr("href").replace("http", "https")
                 )
             }
         } catch (ex: SocketTimeoutException) {