added on disk cache for the timetables

* update spring-boot 2.1.9 -> 2.1.10

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

@@ -22,22 +22,31 @@
 
 package org.mosad.thecitadelofricks.controller
 
+import com.google.gson.Gson
+import com.google.gson.JsonParser
+import org.mosad.thecitadelofricks.TimetableCourseWeek
 import org.slf4j.Logger
 import org.slf4j.LoggerFactory
-import java.io.File
-import java.io.FileInputStream
-import java.io.FileOutputStream
+import java.io.*
 import java.util.*
 
 class StartupController {
 
     private val logger: Logger = LoggerFactory.getLogger(CacheController::class.java)
 
-    private val userHome = System.getProperty("user.home")
-    private val tcorHome = "$userHome/.tcor"
-    private val dirTcorHome = File(tcorHome)
-    private val dirTcorCache = File("$tcorHome/cache")
-    private val fileConfig = File("$tcorHome/config.xml")
+    companion object {
+        val userHome: String = System.getProperty("user.home")
+        val tcorHome = "$userHome/.tcor"
+        val dirTcorHome = File(tcorHome)
+        val dirTcorCache = File("$tcorHome/cache")
+        val fileConfig = File("$tcorHome/config.xml")
+
+        var cachetAPIKey = "0"
+        var cachetBaseURL = "https://status.mosad.xyz"
+        var courseListURL = "https://www.hs-offenburg.de/studium/vorlesungsplaene/"
+        var mensaMenuURL = "https://www.swfr.de/de/essen-trinken/speiseplaene/mensa-offenburg/"
+        var mensaName = "Offenburg"
+    }
 
     init {
         // if the tcor directory doesn't exist, create it
@@ -56,8 +65,14 @@ class StartupController {
         } else {
             createConfig()
         }
+
+        // TODO read cached timetable files, as they are not initially cached
+        readCachedTimetables()
     }
 
+    /**
+     * load the config stored in the config.xml file
+     */
     private fun loadConfig() = try {
         val properties = Properties()
         properties.loadFromXML(FileInputStream(fileConfig))
@@ -90,6 +105,9 @@ class StartupController {
         logger.error("error while loading config", ex)
     }
 
+    /**
+     * create an initial config file
+     */
     private fun createConfig() = try {
         val properties = Properties()
 
@@ -105,32 +123,24 @@ class StartupController {
         logger.error("error while creating config", ex)
     }
 
-    companion object {
-        private var cachetAPIKey = "0"
-        private var cachetBaseURL = "https://status.mosad.xyz"
-        private var courseListURL = "https://www.hs-offenburg.de/studium/vorlesungsplaene/"
-        private var mensaMenuURL = "https://www.swfr.de/de/essen-trinken/speiseplaene/mensa-offenburg/"
-        private var mensaName = "Offenburg"
+    /**
+     * read all previously cached timetables
+     */
+    private fun readCachedTimetables() {
+        dirTcorCache.walkTopDown().forEach {
+            if (it.isFile && it.name.endsWith(".json")) {
+                try {
+                    val fileReader = FileReader(it)
+                    val bufferedReader = BufferedReader(fileReader)
+                    val timetableObject = JsonParser.parseString(bufferedReader.readLine()).asJsonObject
 
-        fun getCachetAPIKey(): String {
-            return cachetAPIKey
+                    CacheController.timetableList.add(Gson().fromJson(timetableObject, TimetableCourseWeek().javaClass))
+                    bufferedReader.close()
+                    fileReader.close()
+                } catch (ex: Exception) {
+                    logger.error("error while reading cache", ex)
+                }
+            }
         }
-
-        fun getCachetBaseURL(): String {
-            return cachetBaseURL
-        }
-
-        fun getCourseListURL(): String {
-            return courseListURL
-        }
-
-        fun getMensaMenuURL(): String {
-            return mensaMenuURL
-        }
-        fun getMensaName(): String {
-            return mensaName
-        }
-
     }
-
 }