How to fix "JAR will be empty - no content was marked for inclusion!" maven-jar-plugin?

Question

When I run maven-jar-plugin, jar:jar i have this warning and empty jar-file

[WARNING] JAR will be empty - no content was marked for inclusion!

The build is successful but the produced jar-file is empty as the warning says.

How can I fix it? Im trying to find solution in ither questions, but all solutions not working

Here is my pom.xml:

<?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>com.actticus.instdbparse</groupId>
    <artifactId>instDBParse</artifactId>
    <version>1.0-SNAPSHOT</version>
    <dependencies>
        <dependency>
            <groupId>com.github.igor-suhorukov</groupId>
            <artifactId>instagramscraper</artifactId>
            <version>2.2</version>
        </dependency>
        <dependency>
            <groupId>org.brunocvcunha.instagram4j</groupId>
            <artifactId>instagram4j</artifactId>
            <version>1.8</version>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.14</version>
        </dependency>
        <dependency>
            <groupId>javax.xml.bind</groupId>
            <artifactId>jaxb-api</artifactId>
            <version>2.3.0</version>
        </dependency>
    </dependencies>
    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-jar-plugin</artifactId>
                <version>2.4</version>
                <configuration>
                    <archive>
                        <index>true</index>
                        <manifest>
                            <mainClass>com.actticus.instdbparse.Main</mainClass>
                        </manifest>
                    </archive>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.codehaus.mojo</groupId>
                <artifactId>exec-maven-plugin</artifactId>
                <version>1.6.0</version>
                <configuration>
                    <cleanupDaemonThreads>false</cleanupDaemonThreads>
                    <classpathScope>test</classpathScope>
                    <mainClass>Main</mainClass>
                </configuration>
                <executions>
                    <execution>
                        <id>run-selenium</id>
                        <phase>integration-test</phase>
                        <goals><goal>java</goal></goals>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>
</project>

Answer 1

Don't run mvn jar:jar, but mvn clean package. The jar:jar goal just packages - without the lifecycle, there is nothing to package.

Look up "Maven lifecycle" to get more background information.