i have a stupid problem. i need to detect changes to an object which i do not own. my code looks lik...

# codereview

[tipsy]

i have a stupid problem. i need to detect changes to an object which i do not own. my code looks like this:

private fun changeListener(obj: Any) {
    fun getObjectString(): String {
        val baos = ByteArrayOutputStream()
        ObjectOutputStream(baos).also { it.writeObject(obj) }.also { it.close() }
        return baos.toString()
    }

    var oldValue = getObjectString()
    Thread {
        while (true) {
            val newValue = getObjectString()
            if (oldValue != newValue) {
                println("Change detected")
                oldValue = newValue
            }
            Thread.sleep(250)
        }
    }.start()
}

[furkan.akdemir]

@tipsy You can achieve it with Delegates.observable()

var name: String by Delegates.observable(_name) { _, oldName, newName ->
        println("Changed from $oldName to $newName")
        _name = newName
    }

[tipsy]

thanks @furkan.akdemir - unfortunately it's a java object that already exists. somewhere in the codebase there is a

MyObject myObject = ...

i have access to myObject and want to know if it changes

[Dominaezzz]

Not a solution but it's bothering me 😅. ObjectOutputStream(baos).also { it.writeObject(obj) }.also { it.close() } -> ObjectOutputStream(baos).use { it.writeObject(obj) }.