How I can read content data from properties file to Properties object?

Question

In my Kotlin project in folder resources I has properties file. How I can read content data from this file to Properties object?

I try this:

 val fis = FileInputStream("resources/pairs_ids.txt")
    prop.load(fis);
    logger.info("ETH_BTC_id = " + prop.get("ETH_BTC"))

But I get error:

Exception in thread "main" java.io.FileNotFoundException: resources\pairs_ids.txt (The system cannot find the path specified)

Answer 1

what I like to do in this case is something like:

@Suppress("UNCHECKED_CAST")
fun <T> getProp(key: String): T {
    val props  = javaClass.classLoader.getResourceAsStream("pairs_ids.txt").use {
        Properties().apply { load(it) }
    }
    return (props.getProperty(key) as T) ?: throw RuntimeException("could not find property $key")
}

it will read the properties and tries to cast a certain property. because of kotlins type inference it can then be used like this:

val foo: String = getProp("ETH_BTC")

or this:

val foo = getProp<String>("ETH_BTC")

Answer 2

val props = Properties()
props.load(...)
props.getProperty("key")

That is the same as with Java