Java POM plugin issue (Unable to parse configuration of mojo org.codehaus.mojo:exec-maven-plugin)

Question

When I run mvn package exec:java I am getting the error. Probably I have a problem with exec-maven-plugin plugin configuration. I am trying to run this demo on the Google cloud platform app engine but deploy always failed. But if I compile it on locale by mvm package its works fine and also I can run the application on locale without any problems.

POM:

<?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.example</groupId>
    <artifactId>demo</artifactId>
    <version>0.1</version>
    <packaging>${packaging}</packaging>

    <parent>
        <groupId>io.micronaut</groupId>
        <artifactId>micronaut-parent</artifactId>
        <version>2.3.1</version>
    </parent>

    <properties>
        <packaging>jar</packaging>
        <jdk.version>11</jdk.version>
        <release.version>11</release.version>
        <micronaut.version>2.3.1</micronaut.version>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <exec.mainClass>com.primari.backend.Application</exec.mainClass>
        <micronaut.runtime>netty</micronaut.runtime>
        <log4j.version>2.9.1</log4j.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>com.github.xmlet</groupId>
            <artifactId>htmlflow</artifactId>
            <version>3.5</version>
            <exclusions>
                <exclusion>
                    <artifactId>commons-lang3</artifactId>
                    <groupId>org.apache.commons</groupId>
                </exclusion>
            </exclusions>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.16</version>
            <scope>compile</scope>
        </dependency>
        <dependency>
            <groupId>io.micronaut</groupId>
            <artifactId>micronaut-inject</artifactId>
            <scope>compile</scope>
        </dependency>
        <dependency>
            <groupId>io.micronaut</groupId>
            <artifactId>micronaut-validation</artifactId>
            <scope>compile</scope>
        </dependency>
        <dependency>
            <groupId>io.micronaut</groupId>
            <artifactId>micronaut-runtime</artifactId>
            <scope>compile</scope>
        </dependency>
        <dependency>
            <groupId>io.micronaut</groupId>
            <artifactId>micronaut-http-client</artifactId>
            <scope>compile</scope>
        </dependency>
        <dependency>
            <groupId>javax.annotation</groupId>
            <artifactId>javax.annotation-api</artifactId>
            <scope>compile</scope>
        </dependency>
        <dependency>
            <groupId>io.micronaut</groupId>
            <artifactId>micronaut-http-server-netty</artifactId>
            <scope>compile</scope>
        </dependency>
        <dependency>
            <groupId>io.micronaut.test</groupId>
            <artifactId>micronaut-test-junit5</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.junit.jupiter</groupId>
            <artifactId>junit-jupiter</artifactId>
            <version>5.4.2</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-lang3</artifactId>
            <version>3.11</version>
            <scope>compile</scope>
        </dependency>
        <dependency>
            <groupId>org.apache.logging.log4j</groupId>
            <artifactId>log4j-slf4j-impl</artifactId>
            <version>${log4j.version}</version>
        </dependency>
        <dependency>
            <groupId>org.apache.logging.log4j</groupId>
            <artifactId>log4j-core</artifactId>
            <version>${log4j.version}</version>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>com.google.cloud.tools</groupId>
                <artifactId>appengine-maven-plugin</artifactId>
                <version>2.2.0</version>
                <configuration>
                    <projectId>primari</projectId>
                    <version>2</version>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-shade-plugin</artifactId>
                <version>3.1.0</version>
                <executions>
                    <execution>
                        <phase>package</phase>
                        <goals>
                            <goal>shade</goal>
                        </goals>
                        <configuration>
                            <transformers>
                                <transformer implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
                                    <mainClass>${exec.mainClass}</mainClass>
                                </transformer>
                                <transformer implementation="org.apache.maven.plugins.shade.resource.ServicesResourceTransformer"/>
                            </transformers>
                        </configuration>
                    </execution>
                </executions>
            </plugin>
            <plugin>
                <groupId>org.codehaus.mojo</groupId>
                <artifactId>exec-maven-plugin</artifactId>
                <version>1.6.0</version>
                <configuration>
                    <executable>java</executable>
                    <arguments>
                        <argument>-noverify</argument>
                        <argument>-XX:TieredStopAtLevel=1</argument>
                        <argument>-Dcom.sun.management.jmxremote</argument>
                        <argument>-classpath</argument>
                        <classpath/>
                        <argument>${exec.mainClass}</argument>
                    </arguments>
                </configuration>
            </plugin>
            <plugin>
                <artifactId>maven-surefire-plugin</artifactId>
                <version>2.22.0</version>
            </plugin>
        </plugins>

        <pluginManagement>
            <plugins>
                <plugin>
                    <groupId>org.apache.maven.plugins</groupId>
                    <artifactId>maven-compiler-plugin</artifactId>
                    <version>3.8.0</version>
                    <configuration>
                        <encoding>UTF-8</encoding>
                        <compilerArgs>
                            <arg>-parameters</arg>
                        </compilerArgs>
                        <annotationProcessorPaths>
                            <path>
                                <groupId>org.projectlombok</groupId>
                                <artifactId>lombok</artifactId>
                                <version>1.18.16</version>
                            </path>
                            <path>
                                <groupId>io.micronaut</groupId>
                                <artifactId>micronaut-inject-java</artifactId>
                                <version>2.3.1</version>
                            </path>
                            <path>
                                <groupId>io.micronaut</groupId>
                                <artifactId>micronaut-validation</artifactId>
                                <version>2.3.1</version>
                            </path>
                        </annotationProcessorPaths>
                    </configuration>
                    <executions>
                        <execution>
                            <id>test-compile</id>
                            <goals>
                                <goal>testCompile</goal>
                            </goals>
                            <configuration>
                                <compilerArgs>
                                    <arg>-parameters</arg>
                                </compilerArgs>
                                <annotationProcessorPaths>
                                    <path>
                                        <groupId>org.projectlombok</groupId>
                                        <artifactId>lombok</artifactId>
                                        <version>1.18.16</version>
                                    </path>
                                    <path>
                                        <groupId>io.micronaut</groupId>
                                        <artifactId>micronaut-inject-java</artifactId>
                                        <version>2.3.1</version>
                                    </path>
                                    <path>
                                        <groupId>io.micronaut</groupId>
                                        <artifactId>micronaut-validation</artifactId>
                                        <version>2.3.1</version>
                                    </path>
                                </annotationProcessorPaths>
                            </configuration>
                        </execution>
                    </executions>
                </plugin>
            </plugins>
        </pluginManagement>

    </build>

</project>

error:

[INFO] --- exec-maven-plugin:1.6.0:java (default-cli) @ demo ---
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  22.012 s
[INFO] Finished at: 2021-02-07T12:23:25+01:00
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.codehaus.mojo:exec-maven-plugin:1.6.0:java (default-cli) on project demo: Unable to parse configuration of mojo org.codehaus.mojo:exec-maven-plugin:1.6.0:java for parameter arguments: Cannot store value into array: arraycopy: element type mismatch: can not cast one of the elements of java.lang.Object[] to the type of the destination array, java.lang.String -> [Help 1]
[ERROR]
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR]
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/PluginConfigurationException

Can you please help me where can by a problem or what I am missing?

Answer 1

Remove empty <classpath/> It's not allowed be there in exec:java goal only String values accepted, see doc exec plugin doc

Another thing is micronaut overrides maven exec plugin argument section see in the project's effective pom, so the possible solution is:

    <arguments combine.self="override">
         <argument>-noverify</argument>
         <argument>-XX:TieredStopAtLevel=1</argument>
         <argument>-Dcom.sun.management.jmxremote</argument>
         <argument>-classpath</argument>    
         <argument>${exec.mainClass}</argument>
     </arguments>

Answer 2

He may have the same problem as you. Failed to execute goal org.codehaus.mojo:exec-maven-plugin:3.0.0:exec (default-cli) on project
I don't understand, but try

<build>
 <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>
             <classpathScope>test</classpathScope>
         </configuration>
     </plugin>
 </plugins>
</build>