Jeamlit Standalone

This is the simplest and most bare-boned install method for Jeamlit. This method is best for simple apps, education, testing, and JBang-like projects.

This page will walk you through installing Jeamlit and creating a simple "Hello world" app. We'll show you two installation methods: using JBang (recommended) or downloading the JAR directly. At the end, you'll build a simple interactive app with a click counter and run it.

Prerequisites

As with any programming tool, in order to install Jeamlit you first need to make sure your computer is properly set up. More specifically, you'll need:

Java JDK >= 21

Download and install a Java JDK (we recommend Eclipse Adoptium).

You can verify your Java installation by running:

java --version
JBang (recommended)

JBang makes it easy to install Jeamlit as a CLI.
Install JBang following the official installation instructions.
Jbang plugin (recommended)
Jeamlit uses the same dependency import feature as Jbang. Install the JBang plugin in your IDE for better code completion and highlighting:
- IntelliJ IDEA: JBang plugin
- VS Code: JBang extension

Install Jeamlit

You have two options to install Jeamlit:

Option 1: Using JBang (recommended)

Open a terminal and install Jeamlit:

# Install Jeamlit with JBang jbang app install jeamlit@jeamlit
Verify the installation by running:

jeamlit --version

Option 2: Download JAR directly

Open a terminal and download the Jeamlit JAR:

# Download Jeamlit JAR curl -L -o jeamlit.jar https://repo1.maven.org/maven2/io/jeamlit/jeamlit/0.44.0/jeamlit-0.44.0-all.jar
Verify the installation by running:

java -jar jeamlit.jar --version

Create a "Hello World" app and run it

Create a file named App.java in your project folder:

/// usr/bin/env jbang "$0" "$@" ; exit $?

// import a dependency with JBang-like imports (optional)
//DEPS org.apache.commons:commons-math3:3.6.1

// NOTE: this Jeamlit import is only here to help the IntelliJ JBang plugin - it is not strictly necessary
//DEPS io.jeamlit:jeamlit:0.23.0

import io.jeamlit.core.Jt;
import org.apache.commons.math3.stat.descriptive.DescriptiveStatistics;

public class App {

    public static void main(String[] args) {
        Jt.title("Hello World !").use();

        Jt.markdown("## A simple click app").use();

        // initialize state - values in the session state are maintained at each update
        Jt.sessionState().putIfAbsent("count", 0);

        // if button is clicked, increment the count value
        if (Jt.button("Click me").use()) {
            Jt.sessionState().computeIfPresentInt("count", (k, v) -> v + 1);
        }

        // display the count
        int count = Jt.sessionState().getInt("count");
        boolean plural = count > 1;
        Jt.markdown("The button was clicked **%s** time%s".formatted(count, plural ? "s" : ""))
                .use();


        // Use the imported library apache commons-math
        Jt.divider().use();
        Jt.markdown("## Using imported apache math dependency").use();
        double[] values = {1.2, 2.3, 3.4, 4.5, 5.6};
        DescriptiveStatistics stats = new DescriptiveStatistics(values);
        double stdDev = stats.getStandardDeviation();
        Jt.text("Computed statistic with Apache commons-math: " + stdDev).use();
    }
}

Run your Jeamlit app:

If you installed with JBang:

jeamlit run App.java

If you downloaded the JAR:

java -jar jeamlit.jar run App.java
Your Jeamlit app should appear in a new tab in your web browser! Try clicking the button to see the counter increment.
To stop the Jeamlit server, press Ctrl+C in the terminal.

Development tips

Hot reload: Edit the App.java file and save it. The app will reload automatically in your browser.
Dependencies: You can add JBang-style dependencies with //DEPS comments at the top of your file.
IDE support: Install the JBang plugin for your IDE to get proper syntax highlighting and code completion.

What's next?

Read about our Basic concepts to understand Jeamlit's dataflow model.

Previous: Installation Next: Embedded

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