try-with-resources: “use” extension function in Kotlin does not always work

Question

I had some trouble expressing the Java\'s try-with-resources construct in Kotlin. In my understanding, every expression that is an instance of AutoClosable shou

Answer 1

For classes that do not support the "use" function, I have done the next homemade try-with-resources:

inline fun  trywr(closeable: T, block: (T) -> R): R {
    try {
        return block(closeable);
    } finally {
        closeable.close()
    }
}

Then you can use it the next way:

fun countEvents(sc: EventSearchCriteria?): Long {
    return trywr(connection.prepareStatement("SELECT COUNT(*) FROM event")) {
        var rs = it.executeQuery()
        rs.next()
        rs.getLong(1)
    }
}