我正试着用java安装我的ds4控制器，然后和他一起做一些事情(是的，控制器是通过蓝牙连接的，我禁用了steam或ds4windows），但问题是：如果我尝试这样做：

for (int i = 0; i < Controllers.getControllers().size; i++) {
        System.out.println(Controllers.getControllers().get(i).getName());
    }

我只是得到一个错误：

Exception in thread "main" java.lang.IllegalArgumentException: key cannot be null.
at com.badlogic.gdx.utils.ObjectMap.locateKey(ObjectMap.java:128)
at com.badlogic.gdx.utils.ObjectMap.containsKey(ObjectMap.java:268)
at com.badlogic.gdx.controllers.Controllers.initialize(Controllers.java:84)
at com.badlogic.gdx.controllers.Controllers.getControllers(Controllers.java:48)
at de.Jan.Controller.DS4.<init>(DS4.java:38)
at de.Jan.Controller.DS4.main(DS4.java:44)

我的pom.xml：

<?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>

<groupId>de.Jan.Controller</groupId>
<artifactId>Controller</artifactId>
<version>1.0-SNAPSHOT</version>
<properties>
    <maven.compiler.source>11</maven.compiler.source>
    <maven.compiler.target>11</maven.compiler.target>
</properties>

<dependencies>
    <!-- https://mvnrepository.com/artifact/uk.co.electronstudio.sdl2gdx/sdl2gdx -->
    <dependency>
        <groupId>uk.co.electronstudio.sdl2gdx</groupId>
        <artifactId>sdl2gdx</artifactId>
        <version>1.0.4</version>
    </dependency>
    <!-- https://mvnrepository.com/artifact/com.badlogicgames.gdx/gdx-controllers -->
    <dependency>
        <groupId>com.badlogicgames.gdx</groupId>
        <artifactId>gdx-controllers</artifactId>
        <version>1.9.12</version>
    </dependency>
    <!-- https://mvnrepository.com/artifact/com.badlogicgames.gdx/gdx -->
    <dependency>
        <groupId>com.badlogicgames.gdx</groupId>
        <artifactId>gdx</artifactId>
        <version>1.9.12</version>
    </dependency>

</dependencies>

<repositories>
    <repository>
        <id>jitpack.io</id>           <!-- JitPack allows github repo to be used as a maven repo -->
        <url>https://jitpack.io</url> <!-- For documentation: http://jitpack.io/ -->
    </repository>
        <repository>
            <snapshots>
                <enabled>false</enabled>
            </snapshots>
            <id>central</id>
            <name>bintray</name>
            <url>https://jcenter.bintray.com</url>
        </repository>
        <repository>
            <id>jitpack.io</id>
            <url>https://jitpack.io</url>
        </repository>
</repositories>

为什么会出现这个错误？我需要额外的图书馆吗？