How to fix "Exception in thread "main" java.lang.NoClassDefFoundError: com/dropbox/core/json/JsonReader$FileLoadException"

If a more experienced StackOverflow user could advise how to make the question more understandable please do.

I am using Eclipse Maven to compile and an example from https://github.com/dropbox/dropbox-sdk-java, more specifcally the authorize example so I can produce and Auth file however when I grab all the code and put it in a new maven project and linked in the sdk to the libraries it still reports the error The error in question reads ~

C:\Authoriser\my-app>java -jar C:\Authoriser\my-app\target\my-app-1.0-SNAPSHOT.jar
Error: A JNI error has occurred, please check your installation and try again
Exception in thread "main" java.lang.NoClassDefFoundError: com/dropbox/core/json/JsonReader$FileLoadException
        at java.lang.Class.getDeclaredMethods0(Native Method)
        at java.lang.Class.privateGetDeclaredMethods(Unknown Source)
        at java.lang.Class.privateGetMethodRecursive(Unknown Source)
        at java.lang.Class.getMethod0(Unknown Source)
        at java.lang.Class.getMethod(Unknown Source)
        at sun.launcher.LauncherHelper.validateMainClass(Unknown Source)
        at sun.launcher.LauncherHelper.checkAndLoadMain(Unknown Source)
Caused by: java.lang.ClassNotFoundException: com.dropbox.core.json.JsonReader$FileLoadException
        at java.net.URLClassLoader.findClass(Unknown Source)
        at java.lang.ClassLoader.loadClass(Unknown Source)
        at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
        at java.lang.ClassLoader.loadClass(Unknown Source)
        ... 7 more

So far I have tried moving the lib files and have looked at other solutions on stack overflow however most seem to be under different context that or I am even more inept. Questions prompted by "Similar Questions" include Exception in thread "main" java.lang.NoClassDefFoundError: com/twitter/chill/KryoBase and Exception in thread "main" java.lang.NoClassDefFoundError: com/google/gson/JsonParseExceptiong however these are under entirely different context further more I have asked on the github itself but without any response (yet).

My pom.xml has additions from stack overflow solutions and these are the only changes to the base file

<plugin>
  <!-- Build an executable JAR -->
  <groupId>org.apache.maven.plugins</groupId>
  <artifactId>maven-jar-plugin</artifactId>
  <version>3.1.0</version>
  <configuration>
    <archive>
      <manifest>
        <addClasspath>true</addClasspath>
        <classpathPrefix>lib/</classpathPrefix>
        <mainClass>com.mycompany.app.App</mainClass>
      </manifest>
    </archive>
  </configuration>
</plugin>

<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-shade-plugin</artifactId>
    <version>3.2.0</version>
    <executions>
        <!-- Attach the shade into the package phase -->
        <execution>
            <phase>package</phase>
            <goals>
                <goal>shade</goal>
            </goals>
            <configuration>
                <transformers>
                    <transformer implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
                        <mainClass>com.mycompany.app.App</mainClass>
                    </transformer>
                </transformers>
            </configuration>
        </execution>
    </executions>
</plugin>

<dependency>
    <groupId>commons-codec</groupId>
    <artifactId>commons-codec</artifactId>
    <version>1.11</version>
</dependency>
<dependency>
    <groupId>com.dropbox.core</groupId>
    <artifactId>dropbox-core-sdk</artifactId>
    <version>3.1.1</version>
</dependency>

My actual code is identical to that of the code in the Dropbox example.

I run mvn clean package while within the correct folder then run java -jar C:\Authoriser\my-app\target\my-app-1.0-SNAPSHOT.jar which produces the aforementioned error rather producing any other errors such as being without any errors.

Solution

I've just created the following pom.xml for the authorize example of the dropbox-sdk-java. Just put it under https://github.com/dropbox/dropbox-sdk-java/tree/master/examples/authorize and see if you can go anywhere with that:

<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/maven-v4_0_0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>com.mycompany.app</groupId>
  <artifactId>my-app</artifactId>
  <packaging>jar</packaging>
  <version>1.0-SNAPSHOT</version>
  <name>my-app</name>
  <url>http://maven.apache.org</url>
  <dependencies>
    <dependency>
        <groupId>com.dropbox.core</groupId>
        <artifactId>dropbox-core-sdk</artifactId>
        <version>3.1.1</version>
    </dependency>
  </dependencies>
  <build>
    <plugins>
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-shade-plugin</artifactId>
        <version>3.2.0</version>
        <executions>
            <!-- Attach the shade into the package phase -->
            <execution>
                <phase>package</phase>
                <goals>
                    <goal>shade</goal>
                </goals>
                <configuration>
                    <transformers>
                        <transformer implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
                            <mainClass>com.dropbox.core.examples.authorize.Main</mainClass>
                        </transformer>
                    </transformers>
                </configuration>
            </execution>
        </executions>
      </plugin>
    </plugins>
  </build>
</project>