[FIXED] Maven error POM Manifest Build with Dependencies Java single jar

Issue

my Maven Java project has many dependencies. I would like to have a single jar with all of them included. I added 2 plugins in my POM file, but I am getting an error. I checked several different posts, it seems that I have the correct POM structure, but I have not been able to fix the issue.

Error in Netbeans build and clean:

------------------------------------------------------------------------
BUILD FAILURE
------------------------------------------------------------------------
Total time:  8.710 s
Finished at: 2020-06-22T20:09:24+02:00
------------------------------------------------------------------------
Failed to execute goal org.apache.maven.plugins:maven-assembly-plugin:2.2-beta-5:single (default) on project CITAM: Unable to parse configuration of mojo org.apache.maven.plugins:maven-assembly-plugin:2.2-beta-5:single for parameter manifest: Cannot find 'manifest' in class org.apache.maven.archiver.ManifestConfiguration -> [Help 1]

To see the full stack trace of the errors, re-run Maven with the -e switch.
Re-run Maven using the -X switch to enable full debug logging.

For more information about the errors and possible solutions, please read the following articles:
[Help 1] http://cwiki.apache.org/confluence/display/MAVEN/PluginConfigurationException

This is my POM file:

<?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.mycompany</groupId>
    <artifactId>CITAM</artifactId>
    <version>1.0</version>
    <packaging>jar</packaging>
    <repositories>
    </repositories>
    <dependencies>
        <!-- https://mvnrepository.com/artifact/org.apache.maven/maven-plugin-api -->
        <dependency>
            <groupId>org.apache.maven</groupId>
            <artifactId>maven-plugin-api</artifactId>
            <version>3.6.3</version>
        </dependency>
        <dependency>
            <groupId>com.opencsv</groupId>
            <artifactId>opencsv</artifactId>
            <version>5.2</version>
        </dependency>
        <dependency>
            <groupId>com.formdev</groupId>
            <artifactId>flatlaf</artifactId>
            <version>0.36</version>
        </dependency>
        <dependency>
            <groupId>org.codehaus.mojo</groupId>
            <artifactId>exec-maven-plugin</artifactId>
            <version>1.6.0</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.apache.maven.plugins/maven-clean-plugin -->
        <dependency>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-clean-plugin</artifactId>
            <version>3.1.0</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.postgresql/postgresql -->
        <dependency>
            <groupId>org.postgresql</groupId>
            <artifactId>postgresql</artifactId>
            <version>42.2.8</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/commons-logging/commons-logging -->
        <dependency>
            <groupId>commons-logging</groupId>
            <artifactId>commons-logging</artifactId>
            <version>1.2</version>
        </dependency>
    </dependencies>
    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <maven.compiler.source>1.8</maven.compiler.source>
        <maven.compiler.target>1.8</maven.compiler.target>
    </properties>
    <name>CITAM</name>
    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-jar-plugin</artifactId>
                <version>3.2.0</version>
                <configuration>
                    <archive>
                        <manifest>
                            <mainClass>com.mycompany.main.Main</mainClass>
                        </manifest>
                    </archive>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-assembly-plugin</artifactId>
                <executions>
                    <execution>
                        <phase>package</phase>
                        <goals>
                            <goal>single</goal>
                        </goals>
                        <configuration>
                            <archive>
                                <manifest>
                                    <manifest>
                                        <mainClass>com.mycompany.main.Main</mainClass>
                                    </manifest>
                                </manifest>
                            </archive>
                            <descriptorRefs>
                                <descriptorRef>jar-with-dependencies</descriptorRef>
                            </descriptorRefs>
                        </configuration>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>
</project>

Thanks a lot for your time and attention.

Fabio

Solution

<manifest>
  <manifest>
     <mainClass>com.mycompany.main.Main</mainClass>
  </manifest>
</manifest>

You've got nested manifest elements, that's your issue.

Answered By - Robert Scholte
Answer Checked By - Terry (JavaFixing Volunteer)