The below instructions describe how to run a Java Main Method using Maven. Maven is a build tool that can be used to manage dependencies, build and test Java projects. The exec-maven-plugin is a plugin for Maven that allows you to run Java code directly from the command line.

Add the maven exec plugin

The first step is to add the plugin to the project's pom.xml file, which is the configuration file for Maven. This is done by adding the plugin's groupId, artifactId, and version, and configuring the plugin to run the "java" goal. The configuration also specifies the main class to be executed.

To run a Java Main Method in Maven, you can use the "exec:java" goal from the exec-maven-plugin. First, add the plugin to your project's pom.xml file:

<plugins>
  <plugin>
    <groupId>org.codehaus.mojo</groupId>
    <artifactId>exec-maven-plugin</artifactId>
    <version>1.6.0</version>
    <executions>
      <execution>
        <goals>
          <goal>java</goal>
        </goals>
      </execution>
    </executions>
    <configuration>
      <mainClass>com.example.Main</mainClass>
    </configuration>
  </plugin>
</plugins>

Make sure to replace "com.example.Main" with the fully qualified name of your main class. You also need to make sure that java is installed in your system and the JAVA_HOME is set.

Run command

Once the plugin is configured, you can run the main method by executing the command "mvn exec:java" in the project's root directory. This will execute the main method of the class specified in the configuration.

mvn exec:java

It is important to note that the main class should be specified in the fully-qualified format, that is package name and class name should be specified. Also, you should make sure that Java is installed and the JAVA_HOME environment variable is set properly on your system for this to work.

Run with main class as argument

You can also run a Java Main Method in Maven by specifying the main class as an argument to the "exec:java" goal. Instead of configuring the main class in the pom.xml file, you can pass it as a command-line argument when running the goal.

For example, if your main class is called "com.example.Main", you can run it with the following command:

mvn exec:java -Dexec.mainClass="com.example.Main"

This will execute the main method of the "com.example.Main" class. You can also specify other arguments for the main method like this:

mvn exec:java -Dexec.mainClass="com.example.Main" -Dexec.args="arg1 arg2"

This command will execute the main method of the "com.example.Main" class with two arguments "arg1" and "arg2".

It's also important to note that you need to make sure that Java is installed in your system and the JAVA_HOME is set. Also, that you are in the root directory of the project where pom.xml is located.

Maven Exec Plugin

The exec-maven-plugin is a plugin for Apache Maven that allows you to run Java code directly from the command line. It's a useful tool for running main methods, executing Java classes, and running other Java code without creating a standalone executable or using an IDE.

The exec-maven-plugin has several goals that can be used to execute different types of Java code. The most commonly used goal is "java", which runs a Java Main Method, but the plugin also provides goals for running Java programs and classes, running Groovy scripts, and running arbitrary command-line applications.

The plugin can be configured in the project's pom.xml file, or it can be run with command-line arguments. The plugin can also be used to pass command-line arguments to the Java code being executed.

It's worth noting that the exec-maven-plugin is a powerful tool that can be used to automate many tasks, but it should be used with care. Because it allows you to execute arbitrary Java code, it can be used to run malicious code or cause other unintended consequences. Therefore it is recommended to always check the code you are running and use appropriate security measures.