CODEWITHSUNDEEP
javaconsole-applicationgradle
missingfaktor
missingfaktor

Reputation: 92056

Console application with Java and gradle

I am writing a console application with Java and gradle. I am using the application plugin and have the required fields correctly configured in build.gradle.

In my main class I have BufferedReader linked with System.in. Here's the problem: When I run gradle run in project directory, the reader does not wait for my console input. BufferedReader#readLine instead returns null on the very first call. This behavior is not desirable for what am I doing.

What is the solution? Is there a separate console application plugin for gradle or do I need to tweak application plugin somehow to suit my needs?

Upvotes: 68

Views: 24497

Answers (4)

Rene Groeschke
Rene Groeschke

Reputation: 28653

By default, the system.in of your Gradle build is not wired up with the system.in of the run (JavaExec) task. You can do the following:

build.gradle (Groovy syntax):

run {
    standardInput = System.in
}

build.gradle.kts (Kotlin DSL syntax):

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

Upvotes: 125

diralik
diralik

Reputation: 7196

For build.gradle.kts:

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

Upvotes: 7

loeschg
loeschg

Reputation: 30581

As stated above, add 

run {
   standardInput = System.in
}

And run:

gradle console:run -q --console=plain

where:

  • -q runs task in "quiet" mode (to avoid having > Building > :run)
  • --console=plain drops execution status: <=-> 80% EXECUTING [TIME]

Source: https://docs.gradle.org/current/userguide/gradle_command_line.html

Upvotes: 41

CaTalyst.X
CaTalyst.X

Reputation: 1665

Chances are, the problem lies in your java code. All the application plugin does is compile the java code, and run the main class that you specify. Can you post the code in your main class that you specified for the application plugin (mainClassName) ?

Upvotes: -4

Related Questions