Mastering High Performance with Kotlin

The disposable pattern

Use the disposable pattern along with the try-finally construction to avoid resource leaks.

The disposable pattern is a pattern for resource management. This pattern assumes that an object represents a resource and that the resource can be released by invoking a method such as close or dispose.

The following example demonstrates how to use them:

fun readFirstLine() : String? {    ......    var bufferedReader: BufferedReader? = null    return try {        ......        bufferedReader = BufferedReader(inputStreamReader)        bufferedReader.readLine()    } catch (e: Exception) {        null    } finally {        ......        bufferedReader?.close()    }}

The Kotlin standard library already has extension functions that use this approach under the hood:

fun readFirstLine(): String? ...