"No operations allowed after connection closed." When using with ktor Server

I am trying to develop a small ktor server that receives a post request with a CSV file as multipart and inserts all rows into a MySQL database. Everything works fine except that the second request to the server always crashes with the following stack trace:

org.jetbrains.exposed.exceptions.ExposedSQLException: com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: No operations allowed after connection closed.
	at org.jetbrains.exposed.sql.statements.Statement.executeIn$exposed(Statement.kt:48)
	at org.jetbrains.exposed.sql.Transaction.exec(Transaction.kt:130)
	at org.jetbrains.exposed.sql.Transaction.exec(Transaction.kt:124)
	at org.jetbrains.exposed.sql.Query.iterator(Query.kt:309)

this is the part of the stack trace after the insert is called by exposed.

at first, I created my SQL connection using URL and password, but now I decided to go with javax.sql.DataSource implementation where I just implemented all getConnection overloads.

after some debugging and searching around in the exposed library I found the following piece of code:

private fun doConnect(getNewConnection: () -> Connection, setupConnection: (Connection) -> Unit = {}, manager: (Database) -> TransactionManager = { ThreadLocalTransactionManager(it, DEFAULT_ISOLATION_LEVEL, DEFAULT_REPETITION_ATTEMPTS) } ): Database {
    return Database {
        getNewConnection().apply { setupConnection(this) }
     }.apply {
        TransactionManager.registerManager(this, manager(this))
    }
}

Here getNewConnection is only called once and not passed to the transaction manager.

is it possible, that this prevents opening a new connection to MySQL when a previous got closed?

Connection creation: val connection: Database = Database.connect(MySqlDataSource())

MySqlDataSource:

    override fun getConnection(): Connection {
        return getConnection("root", "")
    }

    override fun getConnection(username: String?, password: String?): Connection {
        return DriverManager.getConnection("jdbc:mysql://localhost:3306/mydb", username, password)
    }

[virusbear]

Unfortunately, I am not allowed to publish the code for the project, but I will try to create an example to reproduce this issue and publish this one.

[virusbear]

Thank you for your help. Updating to the newest version did indeed help. just really strange why gradle didn’t suggest updating to a newer version.