jar中没有主清单属性

<build>
    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-jar-plugin</artifactId>
            <version>3.2.0</version>
            <configuration>
                <archive>
                    <manifest>
                        <mainClass>com.example.MainClass</mainClass>
                    </manifest>
                </archive>
            </configuration>
        </plugin>
    </plugins>
</build>

jar {
    manifest {
        attributes 'Main-Class': 'com.example.MainClass'
    }
}

my-app/
├── pom.xml
└── src/
    └── main/
        └── java/
            └── com/
                └── example/
                    └── MainClass.java

my-app/
├── build.gradle
└── src/
    └── main/
        └── java/
            └── com/
                └── example/
                    └── MainClass.java

java -jar my-app.jar