Develop Reference

Maven running .JAR file claims missing dependencies

I have a Maven project which uses a few external dependencies, mainly Jackson.
When I run mvn clean -e install, it creates a jar file as specified in the target directory. However, when I run this jar file with java in command line I get the error message:
Error: Unable to initialize main class com.test.package.Main
Caused by: java.lang.NoClassDefFoundError: com/fasterxml/jackson/core/JsonProcessingException
The specific element of Jackson which it's getting confused over does not matter, the error message will point out whatever portion of Jackson the code uses first. The strange part is when I run the project from within IntelliJ, it works fine. It seems that the JAR file does not have access to the proper dependencies.
This is the relevant portion of the pom.xml:
<dependencies>
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-core</artifactId>
<version>${jackson.version}</version>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
<version>${jackson.version}</version>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-annotations</artifactId>
<version>${jackson.version}</version>
</dependency>
<dependency>
<groupId>com.google.guava</groupId>
<artifactId>guava</artifactId>
<version>${guava.version}</version>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>${junit.version}</version>
<scope>test</scope>
</dependency>
</dependencies>
<build>
<pluginManagement>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jar-plugin</artifactId>
<version>2.4</version>
<configuration>
<archive>
<manifest>
<addClasspath>true</addClasspath>
<classpathPrefix>lib/</classpathPrefix>
<mainClass>com.test.package.Main</mainClass>
</manifest>
</archive>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.0</version>
<inherited>true</inherited>
<configuration>
<source>${java.version}</source>
<target>${java.version}</target>
<compilerArgument>-Xlint:unchecked</compilerArgument>
</configuration>
</plugin>
</plugins>
</pluginManagement>
</build>
Is there something I should be doing for the built JAR file to run properly anywhere?

Solved:
This solution from another thread fixed my problem: https://stackoverflow.com/a/42231035/8402030
I had to add a plugin called Maven Shade which creates an uber jar containing all dependencies. Additionally had to remove the plugin from the tag.
Not entirely sure why it matters that the plugin is outside of . If anyone knows, feedback would be appreciated.

Setting up JVM debugging in Maven project

I'm trying to debug my application that's running on a remote JVM, but I can't manage to get my dependencies there too.
Here are a few things I tried:
Remote debugger:
I've set up a remote debugger, and it corrects correctly to the JVM but when I then use my application I get a bunch of NoClassDefFoundError errors coming from external libraries that are in my maven dependencies (which makes sense because I building the app with the Intellij building tools and not Maven itself. I have some relocation rules set up so maybe that's the issue?
The JVM itself is running on my local machine.
Maven debugger
There is a maven debugger integrated inside Intellij but it seems like that is just using the remote JVM during the jar packaging but nothing else. Maybe I'm going something wrong there?
I also have a few yaml files in my resources folder that should be correctly included in the debugger.
Here is my project structure:
Here is my POM file for reference:
<?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>me.playbosswar.com</groupId>
<artifactId>commandtimer</artifactId>
<name>CommandTimer</name>
<version>6.0</version>
<description>Plugin</description>
<build>
<finalName>${project.name}_v${project.version}</finalName>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jar-plugin</artifactId>
<version>2.3.1</version>
<configuration>
<outputDirectory>/Users/tristan/Documents/minecraft/servers/1.16.5/plugins</outputDirectory>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.8.1</version>
<configuration>
<source>1.8</source>
<target>1.8</target>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-shade-plugin</artifactId>
<version>3.2.4</version>
<configuration>
<relocations>
<relocation>
<pattern>com.cryptomorin.xseries</pattern>
<shadedPattern>me.playbosswar.com</shadedPattern>
</relocation>
</relocations>
</configuration>
<executions>
<execution>
<phase>package</phase>
<goals>
<goal>shade</goal>
</goals>
</execution>
</executions>
</plugin>
</plugins>
<resources>
<resource>
<directory>src/main/resources</directory>
<filtering>true</filtering>
</resource>
</resources>
</build>
<repositories>
<repository>
<id>papermc</id>
<url>https://papermc.io/repo/repository/maven-public/</url>
</repository>
<repository>
<id>placeholderapi</id>
<url>http://repo.extendedclip.com/content/repositories/placeholderapi/</url>
</repository>
<repository>
<id>codemc-snapshots</id>
<url>https://repo.codemc.io/repository/maven-snapshots/</url>
</repository>
</repositories>
<dependencies>
<dependency>
<groupId>com.destroystokyo.paper</groupId>
<artifactId>paper-api</artifactId>
<version>1.16.5-R0.1-SNAPSHOT</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>me.clip</groupId>
<artifactId>placeholderapi</artifactId>
<version>2.10.9</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>com.google.code.gson</groupId>
<artifactId>gson</artifactId>
<version>2.8.6</version>
</dependency>
<dependency>
<groupId>com.github.cryptomorin</groupId>
<artifactId>XSeries</artifactId>
<version>7.2.1.2</version>
</dependency>
<dependency>
<groupId>fr.minuskube.inv</groupId>
<artifactId>smart-invs</artifactId>
<version>1.2.7</version>
</dependency>
<dependency>
<groupId>net.wesjd</groupId>
<artifactId>anvilgui</artifactId>
<version>1.5.0-SNAPSHOT</version>
</dependency>
<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-lang3</artifactId>
<version>3.8.1</version>
</dependency>
</dependencies>
</project>
Here is the actual error:

Maven Deploying Project as Jar - Missing Class definition

I am trying to create a runnable jar from a maven project created in Intellij Idea.
I tried building the Artifact through Intellij, but that did not work out. It could not find the main file.
After that I tried it through maven with:
- mvn compile
- mvn package
This creates a runnable jar which executes, but later when parsing a csv it throws an Exception:
Exception in thread "JavaFX Application Thread"
java.lang.NoClassDefFoundError: org/apache/commons/csv/CSVParser
But it is added in my pom.xml... I downloaded everything even the docs. I can see the org.apache.commons:commons-csv package in the external libraries, but it seems to be missing when creating the jar.
<?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>
<packaging>jar</packaging>
<groupId>sceosa</groupId>
<artifactId>CEO_SA_ReportingLine</artifactId>
<version>1.0-SNAPSHOT</version>
<build>
<finalName>CEOSA</finalName>
<plugins>
<!-- download source code in Eclipse, best practice -->
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-eclipse-plugin</artifactId>
<version>2.9</version>
<configuration>
<downloadSources>true</downloadSources>
<downloadJavadocs>false</downloadJavadocs>
</configuration>
</plugin>
<!-- Set a compiler level -->
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>2.3.2</version>
<configuration>
<source>1.8</source>
<target>1.8</target>
</configuration>
</plugin>
<!-- Make this jar executable -->
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jar-plugin</artifactId>
<version>3.1.0</version>
<configuration>
<archive>
<manifest>
<mainClass>de.Main</mainClass>
</manifest>
</archive>
</configuration>
</plugin>
</plugins>
</build>
<dependencies>
<!-- https://mvnrepository.com/artifact/org.hsqldb/hsqldb -->
<!-- https://mvnrepository.com/artifact/org.apache.maven.plugins/maven-compiler-plugin -->
<dependency>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.7.0</version>
</dependency>
<!-- https://mvnrepository.com/artifact/com.google.guava/guava -->
<dependency>
<groupId>com.google.guava</groupId>
<artifactId>guava</artifactId>
<version>25.1-jre</version>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>1.18.0</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-csv</artifactId>
<version>1.3</version>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.12</version>
<scope>test</scope>
</dependency>
</dependencies>
</project>
Can anybody see what is wrong with the pom file or intellij?

By default maven does not include dependencies when building jars. The jar will only work if you have the dependency in some other way.
You can use the maven-assembly-plugin to build a jar-with-dependencies.

I have used the maven-shade-plugin and it works great if you want to bundle all your dependencies into one jar. All you need is the plugin and provide the Main class from your project and it should have a main method. It will look something like this:
<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-shade-plugin</artifactId>
    <executions>
        <execution>
            <goals>
                <goal>shade</goal>
            </goals>
            <configuration>
                <shadedArtifactAttached>true</shadedArtifactAttached>
                <transformers>
                    <transformer implementation=
                      "org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
                        <mainClass>com.test.MainClass</mainClass>
                </transformer>
            </transformers>
        </configuration>
        </execution>
    </executions>
</plugin>
And just build your project using mvn clean install and you should find the the jar in your target directory and it will be suffixed with -shaded.jar. Hope this helps

unable to find logger class while running a maven build jar file

I am trying to write a maven integrated Java API. I have included log4j for logging purpose. Which works well when running through eclipse, but when maven package is done and the jar is run it is unable to run from cmd line using java -jar jar_name.jar throwing an error
Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/log4j/Logger
Now the log4j.properties file is placed under src/main/resources folder. And the pom.xml is mentioned. Have tried searching for answers but none worked for me.
Any help available
<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>Weather_Simulator</groupId>
<artifactId>weather_simulator</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
<name>weather_simulator</name>
<url>http://maven.apache.org</url>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jar-plugin</artifactId>
<version>3.0.2</version>
<configuration>
<archive>
<manifest>
<addClasspath>true</addClasspath>
<mainClass>com.test.weather.simulator.MainClass</mainClass>
</manifest>
</archive>
</configuration>
</plugin>
<plugin>
<!-- NOTE: We don't need a groupId specification because the group is
org.apache.maven.plugins ...which is assumed by default.
-->
<artifactId>maven-assembly-plugin</artifactId>
<version>3.0.0</version>
<configuration>
<descriptorRefs>
<descriptorRef>jar-with-dependencies</descriptorRef>
</descriptorRefs>
</configuration>
</plugin>
</plugins>
</build>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
</properties>
<dependencies>
<dependency>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.6.1</version>
</dependency>
<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-configuration2</artifactId>
<version>2.1.1</version>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>3.8.1</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.apache.logging.log4j</groupId>
<artifactId>log4j-slf4j-impl</artifactId>
<version>2.6.1</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>log4j</groupId>
<artifactId>log4j</artifactId>
<version>1.2.17</version>
</dependency>

Your <scope> in your pom.xml appears to be wrong. Try this (notice I've changed "test" to "compile").
<dependency>
<groupId>org.apache.logging.log4j</groupId>
<artifactId>log4j-slf4j-impl</artifactId>
<version>2.6.1</version>
<scope>compile</scope> <!-- look here -->
</dependency>
The way you currently have your pom.xml configured (with "test"), maven will only provide the log4j jar when doing "mvn test". If you need the jar at both compile time and run time (which is the scenario that appears to be causing problems for you), the scope needs to be "compile".
Note that "compile" is the default scope, so if you leave the <scope> element off, the scope will be "compile".
From the maven docs: "This [compile] is the default scope, used if none is specified. Compile dependencies are available in all classpaths of a project. Furthermore, those dependencies are propagated to dependent projects"
For more info about maven "scopes" look here.

This is a classpath problem, the jar generated by Maven contains only your classes. To fix this you can pack all the dependencies inside your project jar: How can I create an executable JAR with dependencies using Maven?

There are two things you should be aware if you like to create an executable jar which contains all dependent jars you have to use maven-assembly-plugin as you already did but you forgot to bind it to the life cycle...which looks like this:
<project>
[...]
<build>
[...]
<plugins>
<plugin>
<artifactId>maven-assembly-plugin</artifactId>
<version>3.0.0</version>
<configuration>
<descriptorRefs>
<descriptorRef>jar-with-dependencies</descriptorRef>
</descriptorRefs>
</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>
[...]
</project>
Furthermore having plugins as dependencies is simply wrong..
<dependency>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.6.1</version>
</dependency>
This means remove this entry from your pom file.
Defining a dependency with a scope test means it will be available only during the unit tests which means also it will never being packaged into a resulting jar file. This means you have to change the following:
<dependency>
<groupId>org.apache.logging.log4j</groupId>
<artifactId>log4j-slf4j-impl</artifactId>
<version>2.6.1</version>
<scope>test</scope>
</dependency>
into the following:
<dependency>
<groupId>org.apache.logging.log4j</groupId>
<artifactId>log4j-slf4j-impl</artifactId>
<version>2.6.1</version>
</dependency>
After you have fixed those issues you should be able to build your app via:
mvn clean package
and find the resulting jar file which contains the dependencies in the target directory named like weather_simulator-1.0.0-SNAPSHOT-jar-with-dependencies.jar which you should use to call your app.

Execute a Maven build including parameter replacement and then run app from Eclipse

I have a Java application in Eclipse which includes several property files, that have the property values as parameters which the Maven build is supposed to replace with the actual values.
However, when I run the build script with the compile goal, there's nothing created in the target folder except for the manifest.mf file, and then when I run the application, I see that the parameters were not replaced.
Here's my pom file:
<properties>
<driver-version>5.1.38</driver-version>
<jackson-core-version>2.7.0</jackson-core-version>
</properties>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.1</version>
<configuration>
<source>1.7</source>
<target>1.7</target>
</configuration>
</plugin>
</plugins>
<resources>
<resource>
<directory>src/main/resources</directory>
<filtering>true</filtering>
</resource>
</resources>
</build>
<dependencies>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>${driver-version}</version>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-core</artifactId>
<version>${jackson-core-version}</version>
</dependency>
</dependencies>
<profiles>
<profile>
<id>...</id>
<properties>...</properties>
What am I missing? How can I configure Eclipse to run the application with the replaced parameter values?
Thanks.