Why does my Kotlin DSL code for Gradle not enable System.in in my Java project?

Question

I've been trying to write a simple application using Scanner in Java and was having issues. I would constantly get the NoSuchElementException thrown by the scanner no matter what.

Here is my full error, code, and my build.gradle.kts :

Exception in thread "main" java.util.NoSuchElementException: No line found
    at java.base/java.util.Scanner.nextLine(Scanner.java:1651)
    at App.main(App.java:11)

CODE:

public class App {

    public static void main(String[] args) {

        // creates an object of Scanner
        Scanner input = new Scanner(System.in);

        System.out.print("Enter your name: ");

        // takes input from the keyboard
        String name = input.nextLine();

        // prints the name
        System.out.println("My name is " + name);

    }
}

BUILD.GRADLE.KTS :

/*
 * This file was generated by the Gradle 'init' task.
 *
 * This generated file contains a sample Java application project to get you started.
 * For more details on building Java & JVM projects, please refer to https://docs.gradle.org/8.2.1/userguide/building_java_projects.html in the Gradle documentation.
 */

repositories {
    // Use Maven Central for resolving dependencies.
    mavenCentral()
}

dependencies {
    // Use JUnit Jupiter for testing.
    testImplementation("org.junit.jupiter:junit-jupiter:5.9.2")

    testRuntimeOnly("org.junit.platform:junit-platform-launcher")

    // This dependency is used by the application.
    implementation("com.google.guava:guava:31.1-jre")
}

// Apply a specific Java toolchain to ease working on different environments.
java {
    toolchain {
        languageVersion.set(JavaLanguageVersion.of(17))
    }
}

application {
    // Define the main class for the application.
    mainClass.set("project.App")
}

tasks.named<Test>("test") {
    // Use JUnit Platform for unit tests.
    useJUnitPlatform()
}

plugins {
    application
}

tasks.named<JavaExec>("run") {
    standardInput = System.`in`
}

I changed my code a few time, tried with Buffered Reader, but I couldn't get input. I expected it would be a problem with my code, but since I'm new to Gradle, I started exploring the possibility that it's an issue with the way I set up Gradle. I found this thread and tried copy and pasting the kotlin code that other people said worked for them. Looking through the docs, it seems to be correct. Even with this new code snippet (at the bottom of the build.gradle.kts file), I still get NoSuchElementExceptions and cannot get user input. I am running my project with the gradle extension in vscode, but I get the same issue running it in the command prompt (gradle run) on the windows command line.

You forgot to add important information to your question: the complete errors (just an exception name does not qualify) and how do you execute your Java application. — aled, Jul 27 '23 at 01:34
How do you run it in the command line? What is the actual command line you execute? — aled, Jul 27 '23 at 11:32

score 0 · Answer 1 · answered Jul 27 '23 at 22:38

It was an issue with the way I was running it. Using the VSCODE gradle menu on the left sidebar was causing the error, when I ran with cmd line, it wasn't working either, but it worked in powershell. All with the same "gradle run" command. Thanks aled for pointing me in that direction.

Why does my Kotlin DSL code for Gradle not enable System.in in my Java project?

1 Answers1