pom.xml

<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>

  <properties>
    <openrefine.version>3.8.7</openrefine.version>
    <!-- Change the values below, as well as the groupId & url, to reflect your extension -->
    <extension.id>openrefine-sample-extension</extension.id>
    <extension.name>OpenRefine Sample Extension</extension.name>
  </properties>

  <groupId>org.openrefine</groupId>
  <artifactId>${extension.id}</artifactId>
  <packaging>jar</packaging>
  <version>0.1.0</version>

  <name>${extension.name}</name>
  <description>${extension.name} provided for demonstration purposes</description>
  <url>http://openrefine.org/</url>

  <build>
    <plugins>
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-compiler-plugin</artifactId>
        <version>3.13.0</version>
        <configuration>
          <release>11</release> <!-- minimum version of Java required by your extension -->
          <encoding>UTF-8</encoding>
          <showDeprecation>true</showDeprecation>
        </configuration>
      </plugin>
      <!-- package the Java source code of this extension into a .jar file to be loaded by OpenRefine -->
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-jar-plugin</artifactId>
        <version>3.4.2</version>
        <executions>
          <execution>
            <id>default-jar</id>
            <phase>compile</phase>
            <goals>
              <goal>jar</goal>
            </goals>
            <configuration>
              <skipIfEmpty>true</skipIfEmpty>
              <outputDirectory>module/MOD-INF/lib</outputDirectory>
            </configuration>
          </execution>
        </executions>
      </plugin>
      <!-- Add .jar files of all dependencies of this extension -->
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-dependency-plugin</artifactId>
        <version>3.8.1</version>
        <executions>
            <execution>
            <phase>compile</phase>
            <goals>
                <goal>copy-dependencies</goal>
            </goals>
            <configuration>
                <outputDirectory>module/MOD-INF/lib</outputDirectory>
                <includeScope>runtime</includeScope>
            </configuration>
            </execution>
        </executions>
      </plugin>
      <!-- package the extension as a zip file -->
      <plugin>
        <artifactId>maven-assembly-plugin</artifactId>
        <version>3.7.1</version>
        <configuration>
          <appendAssemblyId>false</appendAssemblyId>	
          <descriptors>
            <descriptor>src/assembly/extension.xml</descriptor>
          </descriptors>
        </configuration>
        <executions>
          <execution>
            <id>make-assembly</id>
            <phase>package</phase>
            <goals>
              <goal>single</goal>
            </goals>
          </execution>
        </executions>
      </plugin>
      <!-- Run java unit tests -->
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-surefire-plugin</artifactId>
        <version>3.5.2</version>
      </plugin>
    </plugins>
  </build>

  <dependencies>
     <dependency>
      <groupId>org.openrefine</groupId>
      <artifactId>main</artifactId>
      <version>${openrefine.version}</version>
      <scope>provided</scope>
    </dependency>
    <dependency>
      <groupId>javax.servlet</groupId>
      <artifactId>javax.servlet-api</artifactId>
      <version>4.0.1</version>
      <scope>provided</scope>
    </dependency>

    <!-- add here the dependencies of your extension -->

    <dependency>
      <groupId>org.testng</groupId>
      <artifactId>testng</artifactId>
      <version>7.10.2</version>
      <scope>test</scope>
    </dependency>
    <dependency>
      <groupId>org.openrefine</groupId>
      <artifactId>main</artifactId>
      <version>${openrefine.version}</version>
      <type>test-jar</type>
      <scope>test</scope>
    </dependency>
  </dependencies>
</project>