refactor(util): 添加方法用于快速注册 ShutdownHook.

该功能将在后续提交中使用.

scalabot-app/src/main/kotlin/AppMain.kt

@@ -2,6 +2,7 @@ package net.lamgc.scalabot
 
 import kotlinx.coroutines.runBlocking
 import mu.KotlinLogging
+import net.lamgc.scalabot.util.registerShutdownHook
 import org.telegram.telegrambots.bots.DefaultBotOptions
 import org.telegram.telegrambots.meta.TelegramBotsApi
 import org.telegram.telegrambots.meta.generics.BotSession
@@ -11,6 +12,7 @@ import kotlin.system.exitProcess
 private val log = KotlinLogging.logger { }
 
 private val launcher = Launcher()
+    .registerShutdownHook()
 
 fun main(args: Array<String>): Unit = runBlocking {
     log.info { "ScalaBot 正在启动中..." }
@@ -21,7 +23,7 @@ fun main(args: Array<String>): Unit = runBlocking {
     }
 }
 
-internal class Launcher {
+internal class Launcher : AutoCloseable {
 
     companion object {
         @JvmStatic
@@ -31,6 +33,7 @@ internal class Launcher {
     private val botApi = TelegramBotsApi(DefaultBotSession::class.java)
     private val botSessionMap = mutableMapOf<ScalaBot, BotSession>()
 
+    @Synchronized
     fun launch(): Boolean {
         val botConfigs = loadBotConfig()
         if (botConfigs.isEmpty()) {
@@ -83,6 +86,14 @@ internal class Launcher {
         log.info { "机器人 `${bot.botUsername}` 已启动." }
     }
 
+    @Synchronized
+    override fun close() {
+        botSessionMap.forEach {
+            log.info { "正在关闭机器人 `${it.key.botUsername}` ..." }
+            it.value.stop()
+            log.info { "已关闭机器人 `${it.key.botUsername}`." }
+        }
+    }
 
 }
 

scalabot-app/src/main/kotlin/util/Utils.kt

@@ -1,5 +1,6 @@
 package net.lamgc.scalabot.util
 
+import mu.KotlinLogging
 import net.lamgc.scalabot.ExtensionPackageFinder
 import net.lamgc.scalabot.FinderRules
 import org.eclipse.aether.artifact.Artifact
@@ -63,3 +64,33 @@ internal fun File.deepListFiles(
 internal fun ExtensionPackageFinder.getPriority() =
     this::class.java.getDeclaredAnnotation(FinderRules::class.java)?.priority
         ?: throw NoSuchFieldException("Finder did not add `FinderRules` annotation")
+
+/**
+ * 为 [AutoCloseable] 对象注册 Jvm Shutdown 钩子.
+ * @return 返回对象本身, 方便进行链式调用.
+ */
+fun <T : AutoCloseable> T.registerShutdownHook(): T {
+    UtilsInternal.autoCloseableSet.add(this)
+    return this
+}
+
+private val log = KotlinLogging.logger { }
+
+private object UtilsInternal {
+
+    val autoCloseableSet = mutableSetOf<AutoCloseable>()
+
+    init {
+        Runtime.getRuntime().addShutdownHook(Thread({
+            log.debug { "Closing registered hook resources..." }
+            autoCloseableSet.forEach {
+                try {
+                    it.close()
+                } catch (e: Exception) {
+                    log.error(e) { "An exception occurred while closing the resource. (Resource: `$it`)" }
+                }
+            }
+            log.debug { "All registered hook resources have been closed." }
+        }, "Shutdown-AutoCloseable"))
+    }
+}