Files and resource cleanup on the JVM

A program may receive a student name from standard input or store a report on disk. Reading can fail or encounter the end of input, and a relative file path depends on the working directory. Treat these as explicit conditions rather than assuming every resource exists.

Kotlin/JVM can use Java file APIs. Choose a temporary artifact for practice so the example does not overwrite a user report. Use a clear encoding and a cleanup path. The online compiler’s filesystem is its execution environment, not your computer’s folders.

Save the complete source as Main.kt and use the Kotlin/JVM environment. No separate input file is needed.

Kotlin/JVM · complete program

import java.nio.file.Files
fun main() {
  val path = Files.createTempFile("school-report-", ".txt")
  try {
    Files.writeString(path, "Diya: 80")
    println(Files.readString(path))
  } finally { Files.deleteIfExists(path) }
}

Expected output

Diya: 80

Follow the execution

The JDK creates a unique file. WriteString and readString use their UTF-8 defaults here, and the output shows the stored text. Finally attempts removal after the scope’s operation. The random filename is not printed, keeping the demonstrated result stable.

Your task: Why avoid an existing report path for practice?

Kotlin/JVM · complete program

import java.nio.file.Files
fun main() {
  val path = Files.createTempFile("school-report-", ".txt")
  try {
    Files.writeString(path, "Diya: 80")
    println(Files.readString(path))
  } finally { Files.deleteIfExists(path) }
}

Worked answer

Writing could replace user data. A unique temporary artifact isolates the exercise and can be cleaned up afterward.

Use use for supported Closeable resources so closing occurs after the block. Filesystem operations can fail because of permissions or storage conditions, including cleanup itself. These APIs are JVM-specific and require the stated JDK environment.

Writing could replace user data. A unique temporary artifact isolates the exercise and can be cleaned up afterward. Use use for supported Closeable resources so closing occurs after the block.

Further reading: official Kotlin documentation for this topic.