maven：没有主要清单属性

Question

我正在开发我的 web java 项目。当我尝试运行由 maven 构建的 java jar 文件时，出现错误：

no main manifest attribute, in "project name".

我认为原因是 maven 找不到我的主要课程。我创建了具有此层次结构的测试项目：

/test

    /src

        /main

             Main.java

    pom.xml

pom.xml 文件包含以下内容：

<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>FirstProject</groupId>

<artifactId>FirstProject</artifactId>

<version>1.0</version>

<properties>

    <maven.compiler.source>1.8</maven.compiler.source>

    <maven.compiler.target>1.8</maven.compiler.target>

</properties>

<build>

    <plugins>

        <plugin>

            <groupId>org.apache.maven.plugin</groupId>

            <artifactId>maven-jar-plugin</artifactId>

            <version>2.4</version>

        </plugin>

        <plugin>

            <artifactId>maven-assembly-plugin</artifactId>

            <configuration>

                <descriptorRefs>

                    <descriptorRef>jar-with-dependencies</descriptorRef>

                </descriptorRefs>

                    <outputDirectory>${basedir}</outputDirectory>

                    <finalName>server</finalName>

                    <appendAssemblyId>false</appendAssemblyId>

                 <archive>

                        <manifest>

                            <mainClass>main.Main</mainClass>

                        </manifest>

                    </archive>

                </configuration>

    </plugin>

    </plugins>

</build>

在测试项目中也会出现此错误。我试图用谷歌搜索它，每个人都建议添加 pom.xml，但我已经这样做了......（在我的情况下，这不是一个解决方案）。我怎么解决这个问题？

Answer 1

阴影插件更容易使用：<build>&nbsp; &nbsp; &nbsp; &nbsp; <plugins>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <plugin>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <groupId>org.apache.maven.plugins</groupId>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <artifactId>maven-compiler-plugin</artifactId>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <configuration>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <source>1.8</source>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <target>1.8</target>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; </configuration>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; </plugin>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <plugin>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <groupId>org.apache.maven.plugins</groupId>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <artifactId>maven-shade-plugin</artifactId>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <version>3.0.0</version>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <executions>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <execution>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <phase>package</phase>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <goals>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <goal>shade</goal>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; </goals>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <configuration>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <transformers>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <transformer&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <manifestEntries>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <Main-Class>main.Main</Main-Class>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; </manifestEntries>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; </transformer>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; </transformers>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; </configuration>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; </execution>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; </executions>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; </plugin>&nbsp; &nbsp; &nbsp; &nbsp; </plugins>&nbsp; &nbsp; </build>

Answer 2

正如之前有人提到的，正确的项目结构应该是：${projectDir}/src/main/java/Main.java如果您想使用${projectDir}/src/main/java/main/Main.java然后尝试在您拥有的插件之前将下一个代码块添加到您的插件中：<plugin>&nbsp; &nbsp; <groupId>org.apache.maven.plugins</groupId>&nbsp; &nbsp; <artifactId>maven-jar-plugin</artifactId>&nbsp; &nbsp; <configuration>&nbsp; &nbsp; &nbsp; &nbsp; <archive>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <manifest>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <mainClass>main.Main</mainClass>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; </manifest>&nbsp; &nbsp; &nbsp; &nbsp; </archive>&nbsp; &nbsp; </configuration></plugin>