How to resolve dependencies on JNLP with Maven

Question

I'm working on a Slick 2D project, with JDK 15, using Eclipse 09-2020, and I am resolving my dependencies via Maven. When I add Slick2D to pom.xml, it shows an error in the IDE at xsi:schemaLocation, saying "Missing artifact javax.jnlp:jnlp-api:jar:5.0"

I've tried re-downloading Java, resetting my JAVA_HOME variable, but to no avail. The other problems that I've come across reference "javaw.jar" in the lib directory, but that is not present in my JDK. How do I solve this?

Here's my pom.xml, if it helps:

<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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>org.newproject</groupId>
<artifactId>newapi</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>Slick Based API</name>

<dependencies>
    <dependency>
        <groupId>org.slick2d</groupId>
        <artifactId>slick2d-core</artifactId>
        <version>1.0.2</version>
    </dependency>
</dependencies>

Answer 1

Just a general note: The slick project seems dead. The official source repo has been taken offline . I would probably not use it for a completely new project. But now to your question:

Java Webstart has been removed starting from Java11 since oracle did not opensource it. So what can you do?

1. You downgrade to Java 9/10
2. You use https://openwebstart.com (some adaptions might be necessary)
3. You remove JNLP from the project (since there are other means to start it)

Some other guy seems to have taken up the project. You can find it on github . In one of the forks JNLP has been removed, too.