synchronized PrepareStatement

src/main/kotlin/kr/foundcake/sch_sw_notice/database/ChannelDB.kt

@@ -23,29 +23,35 @@ class ChannelDB(conn: Connection) {
 	)
 
 	fun registerChannel(serverId: Long, channelId: Long) : Boolean{
-		registerChannelStmt.setLong(1, serverId)
-		registerChannelStmt.setLong(2, channelId)
-		registerChannelStmt.setLong(3, channelId)
-		return registerChannelStmt.execute()
+		synchronized(registerChannelStmt) {
+			registerChannelStmt.setLong(1, serverId)
+			registerChannelStmt.setLong(2, channelId)
+			registerChannelStmt.setLong(3, channelId)
+			return registerChannelStmt.execute()
+		}
 	}
 
 	private val removeChannelByServerIdStmt: PreparedStatement = conn.prepareStatement(
 		"DELETE FROM `channel_db` WHERE `serverId`=?"
 	)
 
 	fun removeChannelByServerId(serverId: Long): Boolean {
-		removeChannelByServerIdStmt.setLong(1, serverId)
-		return removeChannelByServerIdStmt.execute()
+		synchronized(removeChannelByServerIdStmt) {
+			removeChannelByServerIdStmt.setLong(1, serverId)
+			return removeChannelByServerIdStmt.execute()
+		}
 	}
 
 	private val removeChannelByChannelIdStmt: PreparedStatement = conn.prepareStatement(
 		"DELETE FROM `channel_db` WHERE `serverId`=? and `channelId`=?"
 	)
 
 	fun removeChannelByChannelId(serverId: Long, channelId: Long) : Boolean{
-		removeChannelByChannelIdStmt.setLong(1, serverId)
-		removeChannelByChannelIdStmt.setLong(2, channelId)
-		return removeChannelByChannelIdStmt.execute()
+		synchronized(removeChannelByChannelIdStmt) {
+			removeChannelByChannelIdStmt.setLong(1, serverId)
+			removeChannelByChannelIdStmt.setLong(2, channelId)
+			return removeChannelByChannelIdStmt.execute()
+		}
 	}
 
 	private val getChannelsStmt: PreparedStatement = conn.prepareStatement(

src/main/kotlin/kr/foundcake/sch_sw_notice/database/NoticeDB.kt

@@ -28,10 +28,12 @@ class NoticeDB(conn: Connection) {
 	)
 
 	fun addNotice(notice: Notice) : Boolean {
-		addNoticeStmt.setString(1, notice.title)
-		addNoticeStmt.setString(2, notice.url)
-		addNoticeStmt.setString(3, notice.author)
-		return addNoticeStmt.execute()
+		synchronized(addNoticeStmt) {
+			addNoticeStmt.setString(1, notice.title)
+			addNoticeStmt.setString(2, notice.url)
+			addNoticeStmt.setString(3, notice.author)
+			return addNoticeStmt.execute()
+		}
 	}
 
 	private val removeNoticeStmt: PreparedStatement = conn.prepareStatement(