Adding Javalin dependencies

Question

I'm trying to use Javalin in my project and I can't seem to understand how to add the needed dependencies in order to work with Javalin without compliation errors. The project i'm working on is not a Maven project, it is a simple Java project so it won't be downloaded automatically. How do I add the dependencies and where? I am using VSCode but can Switch to Intellij IDEA if needed.

Thanks.

andrewJames · Answer 1 · 2022-05-07T00:59:34.263

At the risk of pointing you in a direction you may not want to go in... Use a dependency manager (Maven, Gradle, Ivy, or similar). Simple Java projects can be dependency-managed projects, too!

A basic Javalin project includes dozens of dependencies - and dependencies of those dependencies... You will probably have an unpleasant time attempting to handle them all manually, one-by-one.

If you use the Javalin bundle, that will take care of all of this for you.

To give you a sense of what I mean:

If you do decide to use a dependency manager, then your follow-up questions are well covered elsewhere. Or you can ask a follow-up, based on any problems you may encounter.

Update

Yeah but were doing it in a school project and were already half way through the project and now I need to add a Web Client and we don't want to change things all through the project, there's gotta be a way to add those dependencies without creating a new Maven project for it.

You can install Maven and run a command to download all the JARs to a directory.

This is (in my opinion) more work than just using Maven already built into all mainstream IDEs, but here are the steps:

Note: My set-up assumes Windows. You can adjust as needed for Linux or a different OS.

Download Maven - see here.

I downloaded the binary zip archive.

Set up Maven - see here.

Be sure to pay particular attention to the instructions regarding setting the JAVA_HOME environment variable pointing to your JDK installation or having the java executable on your PATH.

I installed my Maven here:

C:\maven\apache-maven-3.8.5

I tested it in a shell using the mvn -v command:

C:\maven\apache-maven-3.8.5\bin\mvn -v

Create a pom.xml file. Maven uses this as its instructions for what to download (and to what location).

In my case I created the POM here:

C:\maven\demo\pom.xml

Its contents are:

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <maven.compiler.source>17</maven.compiler.source>
        <maven.compiler.target>17</maven.compiler.target>
    </properties>
    
    <groupId>org.andrewjames</groupId>
    <artifactId>my-Javalin-demo</artifactId>
    <version>1.0-SNAPSHOT</version>

    <dependencies>
        <dependency>
            <groupId>io.javalin</groupId>
            <artifactId>javalin-bundle</artifactId>
            <version>4.5.0</version>
        </dependency>
    </dependencies>

    <build>
        <finalName>my-Javalin-demo</finalName>
        <plugins>
            
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-dependency-plugin</artifactId>
                <version>3.3.0</version>
                <executions>
                    <execution>
                        <id>copy-dependencies</id>
                        <phase>package</phase>
                        <goals>
                            <goal>copy-dependencies</goal>
                        </goals>
                        <configuration>
                            <silent>true</silent>
                            <outputDirectory>C:/maven/demo</outputDirectory>
                        </configuration>
                    </execution>
                </executions>
            </plugin>
                        
        </plugins>
    </build>

    
    <name>my-Javalin-demo</name>
</project>

The maven.compiler sections assume I have Java 17 available. You may need to adjust to match your Java version.

The dependencies section is where the javalin-bundle is defined.

The execution section is the directive which causes all dependency JARs to be downloaded to the Maven local repository, and then copied to a new directory.

In my case the new directory will be created here:

C:\maven\demo\target\dependency

Open a CMD shell and cd to C:\maven\demo
At the command line, run the following command:

C:\maven\apache-maven-3.8.5\bin\mvn dependency:copy-dependencies

After that has completed, you will see approx. 100 JAR files in the C:\maven\demo\target\dependency directory.

You don't "install the bundle", as such. Instead, first choose which IDE you want to use and which dependency management tool (e.g. let's say you choose Intellij IDEA with Maven). Then set up your project accordingly (e.g. any of the [Working with Maven](https://www.jetbrains.com/idea/guide/tutorials/working-with-maven/) guides). Maven then "installs the bundle" for you - meaning it takes care of downloading all the JARs you need. This may be some extra up-front work for you and a new tool to learn, but it will be a good investment of your time, I think. — andrewJames, May 06 '22 at 18:45
Yeah but were doing it in a school project and were already half way through the project and now I need to add a Web Client and we don't want to change things all through the project, there's gotta be a way to add those dependencies without creating a new Maven project for it. — Sasha Uzelevski, May 06 '22 at 23:59
See updates in my answer. Once you have the JARs you can integrate them into your project in whatever way you have already integrated your existing JARs. — andrewJames, May 07 '22 at 00:59

Adding Javalin dependencies

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