We Keep Coding

Error: Unable to initialize main class Caused by: java.lang.NoClassDefFoundError: org/bson/conversions/Bson

https://github.com/Gjonathan252/AutoPart-Java-Database-w-MongoDB
Its my first time using maven and I am trying to run the .jar of my program but I keep getting this error in the command prompt when I run.
java -jar autopartsjavamongodb-1.0-SNAPSHOT.jar
result:
Error: Unable to initialize main class com.example.autopartsjavamongodb.main
Caused by: java.lang.NoClassDefFoundError: org/bson/conversions/Bson
The Java program uses mongodb dependencies and they all seem to be working when I run the program on the IDE or using this long command on the command prompt.
"C:\Program Files\Java\jdk-16.0.2\bin\java.exe" "-javaagent:C:\Program Files\JetBrains\IntelliJ IDEA Community Edition 2021.2\lib\idea_rt.jar=63226:C:\Program Files\JetBrains\IntelliJ IDEA Community Edition 2021.2\bin" -Dfile.encoding=UTF-8 -classpath "D:\Computer Science Lessons\AutoPart Java Database w MongoDB\target\classes;C:\Users\gjona\.m2\repository\org\mongodb\mongodb-driver-sync\4.3.1\mongodb-driver-sync-4.3.1.jar;C:\Users\gjona\.m2\repository\org\mongodb\bson\4.3.1\bson-4.3.1.jar;C:\Users\gjona\.m2\repository\org\mongodb\mongodb-driver-core\4.3.1\mongodb-driver-core-4.3.1.jar" com.example.autopartsjavamongodb.main
This is what the pom.xml file looks like. I dont think I am missing any depencacies as I am able to run it on the IDE.
<modelVersion>4.0.0</modelVersion>
<groupId>com.example</groupId>
<artifactId>autopartsjavamongodb</artifactId>
<version>1.0-SNAPSHOT</version>
<packaging>jar</packaging>
<properties>
<maven.compiler.release>11</maven.compiler.release>
<maven.compiler.source>16</maven.compiler.source>
<maven.compiler.target>16</maven.compiler.target>
</properties>
<dependencies>
<dependency>
<groupId>org.mongodb</groupId>
<artifactId>mongodb-driver-sync</artifactId>
<version>4.0.5</version>
</dependency>
<dependency>
<groupId>org.mongodb</groupId>
<artifactId>mongodb-driver-sync</artifactId>
<version>4.3.1</version>
</dependency>
<dependency>
<groupId>org.mongodb</groupId>
<artifactId>bson</artifactId>
<version>4.0.5</version>
</dependency>
</dependencies>
<build>
<pluginManagement>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.8.1</version>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jar-plugin</artifactId>
<configuration>
<archive>
<manifest>
<mainClass>com.example.autopartsjavamongodb.main</mainClass>
</manifest>
</archive>
</configuration>
</plugin>
</plugins>
</pluginManagement>
</build>

Normally, when we package a project into a jar file, the jar file doesn't contain its dependencies, so the dependency jar files would need to be included in the classpath.
One way to achieve that is by using maven-assembly-plugin
As a result, all the dependency jars would be packaged in one jar.
pom.xml example
`<plugin>
<artifactId>maven-assembly-plugin</artifactId>
<executions>
<execution>
<phase>package</phase>
<goals>
<goal>single</goal>
</goals>
</execution>
</executions>
<configuration>
<descriptorRefs>
<descriptorRef>jar-with-dependencies</descriptorRef>
</descriptorRefs>
<archive>
<manifest>
<addClasspath>true</addClasspath>
<classpathPrefix>libs/</classpathPrefix>
<mainClass>com.example.autopartsjavamongodb.main</mainClass>
</manifest>
</archive>
</configuration>
</plugin>`
Also please note pluginManagement tag is used to define the plugin version in your parent POM, in your case you shouldn't include pluginManagement tag

Jar executable but can not find the classpath for main class

We have this small program we made and we wanna create an executable jar. Screenshot of my maven dependency and the project structure The problem is that I use Maven install and create a jar and in my pom, I have this plugin:
<plugin>
<!-- Build an executable JAR -->
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jar-plugin</artifactId>
<configuration>
<archive>
<manifest>
<addClasspath>true</addClasspath>
<classpathPrefix>lib/</classpathPrefix>
<mainClass>Main</mainClass>
</manifest>
</archive>
</configuration>
</plugin>
I have been trying Project.Main and as in the code just Main ( Main) but I do always get this error in the terminal:
java -jar /home/haraldur/Desktop/Skolinn/508/Project/target/Project-1.0.jar
Error: Could not find or load main class Main
Caused by: java.lang.NoClassDefFoundError: javafx/application/Application

try dependency !?
<dependency>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.8.1</version>
</dependency>

Maven Java integration

Here's a simple Java code with SL4J built with maven. Following commands have no issues. All of them work well
mvn compile
mvn package
mvn clean install
mvn exec:java
But when I try any of the following
java -cp target/MaventestApp-1.0-SNAPSHOT.jar com.maven.helloworld.App
jar tf ./target/MaventestApp-1.0-SNAPSHOT.jar
I get the following error
exception in thread "main" java.lang.NoClassDefFoundError: org/slf4j/LoggerFactory
at com.maven.helloworld.App.main(App.java:17)
Caused by: java.lang.ClassNotFoundException: org.slf4j.LoggerFactory
at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:338)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
Here is the relevant part of my pom.xml file:
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<maven.compiler.source>1.7</maven.compiler.source>
<maven.compiler.target>1.7</maven.compiler.target>
<slf4jVersion>1.6.1</slf4jVersion>
</properties>
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.11</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-simple</artifactId>
<version>${slf4jVersion}</version>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-api</artifactId>
<version>${slf4jVersion}</version>
</dependency>
</dependencies>
<build>
<pluginManagement><!-- lock down plugins versions to avoid using Maven defaults (may be moved to parent pom) -->
<plugins>
<plugin>
<artifactId>maven-clean-plugin</artifactId>
<version>3.0.0</version>
</plugin>
<!-- see http://maven.apache.org/ref/current/maven-core/default-bindings.html#Plugin_bindings_for_jar_packaging -->
<plugin>
<artifactId>maven-resources-plugin</artifactId>
<version>3.0.2</version>
</plugin>
<plugin>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.7.0</version>
</plugin>
<plugin>
<artifactId>maven-surefire-plugin</artifactId>
<version>2.20.1</version>
</plugin>
<plugin>
<artifactId>maven-jar-plugin</artifactId>
<version>3.0.2</version>
<configuration>
<archive>
<manifest>
<addClasspath>true</addClasspath>
<mainClass>com.maven.helloworld.App</mainClass>
</manifest>
</archive>
</configuration>
</plugin>
<plugin>
<artifactId>maven-install-plugin</artifactId>
<version>2.5.2</version>
</plugin>
<plugin>
<artifactId>maven-deploy-plugin</artifactId>
<version>2.8.2</version>
</plugin>
<plugin>
<groupId>org.codehaus.mojo</groupId>
<artifactId>exec-maven-plugin</artifactId>
<version>1.2.1</version>
<executions>
<execution>
<goals>
<goal>java</goal>
</goals>
</execution>
</executions>
<configuration>
<mainClass>com.maven.helloworld.App</mainClass>
</configuration>
</plugin>
</plugins>
</pluginManagement>
</build>
Code for this sample is here
Can someone help me understand maven and execution process better? Appreciate your time.

The problem is how you are building your JAR file (dependencies are no included in it). You could use maven-assembly-plugin instead (see the differences between assembly and jar plugin here).
Basically, replace your current build section by the following:
<build>
<plugins>
<plugin>
<artifactId>maven-assembly-plugin</artifactId>
<configuration>
<archive>
<manifest>
<mainClass>com.maven.helloworld.App</mainClass>
</manifest>
</archive>
<descriptorRefs>
<descriptorRef>jar-with-dependencies</descriptorRef>
</descriptorRefs>
</configuration>
<executions>
<execution>
<id>make-assembly</id>
<phase>package</phase>
<goals>
<goal>single</goal>
</goals>
</execution>
</executions>
</plugin>
</plugins>
</build>
Then execute the generated jar-with-dependencies using the following command:
java -jar target/MaventestApp-1.0-SNAPSHOT-jar-with-dependencies.jar
See more about creating executable JARs here.

There is the Exec Maven Plugin that should do the job. Something like
mvn exec:java -Dexec.mainClass=com.maven.helloworld.App
The actual problem is that you only add your jar to the classpath and since you do not have the sl4j-classes inside your own archive but declared them as external dependency they are simple missing (aka NoClassDefFoundError).
The command above links all runtime dependencies to the classpath as configured in the pom.

Run Java Maven project with Linux command line

I have a Java project that prints "Hello world !". It runs well under Eclipse/Windows and on a Linux server with the command:
java MyClass.java; javac MyClass
Now that I have converted the project to a Maven project it's still running fine in Eclipse, but I can't find how to run it with a Linux command. I tried many answers that I found on forums but none work for me.
Here is an example of what I tested:
mvn package install;
cd target;
java -cp myApp-0.0.1-SNAPSHOT.jar mypackage.Mylass;
This results to an error:
Error: Could not find or load main class mypackage.Mylass
So, how can I run the Maven code on Linux without generating a jar file or at least make it work with a command line?

i finally managed to make it work thanks to all the answers.
here is what i did
i moved my Main class to the outside of packages and deleted/regenerated a new POM file with
<manifest>
<mainClass>Myclass</mainClass>
</manifest>
but i got some dependency errors so i generated a jar file with the dependency by adding maven plugin jar-with-dependencies
so here is what the build part of my POM file looks like now
....
</dependencyManagement>
<build>
<sourceDirectory>src</sourceDirectory>
<plugins>
<plugin>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.0</version>
<configuration>
<source>1.7</source>
<target>1.7</target>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jar-plugin</artifactId>
<configuration>
<archive>
<manifest>
<mainClass>MyClass</mainClass>
</manifest>
</archive>
</configuration>
</plugin>
<plugin>
<artifactId>maven-assembly-plugin</artifactId>
<version>3.0.0</version>
<configuration>
<descriptorRefs>
<descriptorRef>jar-with-dependencies</descriptorRef>
</descriptorRefs>
<archive>
<manifest>
<mainClass>MyClass</mainClass>
</manifest>
</archive>
</configuration>
<executions>
<execution>
<id>make-assembly</id> <!-- this is used for inheritance merges -->
<phase>package</phase> <!-- bind to the packaging phase -->
<goals>
<goal>single</goal>
</goals>
</execution>
</executions>
</plugin>
</plugins>
</build>
and here is how i execute it .
rm -rf target/ #delete old generated files
mvn install package # generate new jar files
java -jar target/App-0.0.1-SNAPSHOT-jar-with-dependencies.jar # execution
i hope this can save someone else's time
thanks for your help

You've specify a main class in the manifest of myApp-0.0.1-SNAPSHOT.jar
Add the next snippet of code to your pom file.
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jar-plugin</artifactId>
<configuration>
<archive>
<manifest>
<mainClass>mypackage.Mylass</mainClass>
</manifest>
</archive>
</configuration>
</plugin>
</plugins>
</build>
This's the complete pom.file
http://maven.apache.org/maven-v4_0_0.xsd">
4.0.0
com.mycompany.app
my-app
jar
1.0-SNAPSHOT
my-app
http://maven.apache.org
junit
junit
3.8.1
test
<dependency>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.6.1</version>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jar-plugin</artifactId>
<configuration>
<archive>
<manifest>
<mainClass>com.mycompany.app.App</mainClass>
</manifest>
</archive>
</configuration>
</plugin>
</plugins>
</build>

Can you confirm the class name you can trying to run ?
As per your comment, originally ran the class using below command.
java MyClass.java; javac MyClass - here the class name is MyClass
After maven install, it should be invoked using
mvn package install;
cd target;
java -cp myApp-0.0.1-SNAPSHOT.jar mypackage.MyClass;

No main manifest attribute error when running jar

I have create a maven project. It is running fine. Now i want to run my code through jar. After maven build i got a jar file in .m2 folder. When I try to run this jar using
java -jar "jar path"
getting no main manifest attribute, in "jar path".
My POM.xml is
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.3</version>
<configuration>
<source>1.8</source>
<target>1.8</target>
</configuration>
</plugin>
<plugin>
<groupId>org.codehaus.mojo</groupId>
<artifactId>exec-maven-plugin</artifactId>
<version>1.2.1</version>
<configuration>
<mainClass>main.Application</mainClass>
</configuration>
</plugin>
</plugins>
</build>
Please suggest how to get over rid of the problem.

Now i want to run my code through jar
exec-maven-plugin is for executing a program during a maven build.
You don't want it.
And as a side note, you don't have specified any goal for it.
So, it will do nothing.
You want to package your jar in a way that it is executable.
So use rather the maven-jar-plugin :
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jar-plugin</artifactId>
<configuration>
<archive>
<manifest>
<mainClass>main.Application</mainClass>
</manifest>
</archive>
</configuration>
</plugin>
To create a JAR with dependencies specified in the pom, instead of, use the maven-assembly-plugin with the jar-with-dependencies descriptorRef:
<build>
<plugins>
<plugin>
<artifactId>maven-assembly-plugin</artifactId>
<configuration>
<archive>
<manifest>
<mainClass>main.Application</mainClass>
</manifest>
</archive>
<descriptorRefs>
<descriptorRef>jar-with-dependencies</descriptorRef>
</descriptorRefs>
</configuration>
</plugin>
</plugins>
</build>