mainClass
到 main 文件顶部看看 package org.example
或者是 随便填一个先打包,然后看看 jar 中的目录结构

打包为 exe

https://github.com/fvarrui/JavaPackager
可以打包到 windows mac linux . 具体的看 github

<properties>
    <main.class>org.example.Main</main.class>
</properties>

<build>
    <plugins>
        <plugin>
            <groupId>io.github.fvarrui</groupId>
            <artifactId>javapackager</artifactId>
            <version>1.7.2</version>
            <executions>
                <execution>
                    <phase>package</phase>
                    <goals>
                        <goal>package</goal>
                    </goals>
                    <configuration>
                        <mainClass>${main.class}</mainClass>
                        <!-- 不生成安装程序 -->
                        <generateInstaller>false</generateInstaller>
                    </configuration>
                </execution>
            </executions>
        </plugin>
    </plugins>
</build>              

打包 可执行 jar

maven-assembly-plugin

<properties>

     <main.class>org.example.Main</main.class>
        
</properties>

<build>
    <sourceDirectory>src/main/java</sourceDirectory>
    <testSourceDirectory>src/test/java</testSourceDirectory>
    <plugins>
        <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>
                                <mainClass>
                                    ${main.class}
                                </mainClass>
                            </manifest>
                        </archive>
                        <descriptorRefs>
                            <descriptorRef>jar-with-dependencies</descriptorRef>
                        </descriptorRefs>
                    </configuration>
                </execution>
            </executions>
        </plugin>
    </plugins>
</build>