java - 为什么在尝试使用 Maven 程序集插件时出现此错误消息？

Question

我是 Maven 的新手，我正在学习教程。

在本教程中，我有以下 pom.xml 配置文件:

<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.denofprogramming</groupId>
    <artifactId>maventutorial1</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>MavenTutorial1</name>
    <url>http://maven.apache.org</url>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>


    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.1</version>
                <configuration>
                    <source>1.7</source>
                    <target>1.7</target>
                </configuration>
            </plugin>

            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-assembly-plugin</artifactId>
                <version>2.5.5</version>
                <configuration>
                    <descriptors>
                        <descriptor>jar-with-dependencies</descriptor>
                    </descriptors>
                </configuration>
            </plugin>
        </plugins>
    </build>

    <dependencies>
        <dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-math3</artifactId>
            <version>3.2</version>
        </dependency>

        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.11</version>
            <scope>test</scope>
        </dependency>
    </dependencies>

</project>

正如你在这个配置文件中看到的，它被声明使用assembly插件，这部分:

        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-assembly-plugin</artifactId>
            <version>2.5.5</version>
            <configuration>
                <descriptors>
                    <descriptor>jar-with-dependencies</descriptor>
                </descriptors>
            </configuration>
        </plugin>

作为 descripor 字段，它被设置为 jar-with-dependencies 值(据我所知)必须创建一个新的目标 jar 文件，其中还包含删除我项目的 .jar 依赖项。

因此，进入 Eclipse，我选择我的项目和 Run as ---> Maven Build 并进入 Goal 输入部分我写下这条语句:

clean package assembly:single

必须清理我的项目的目标目录，创建包并在 assembly 插件上调用 single 目标，将 jar 依赖项放入我的最终 jar 目标我的项目文件。

问题是，以这种方式我在 Eclipse 控制台中收到以下错误消息:

.......................................................
.......................................................
.......................................................

Results :

Tests run: 2, Failures: 0, Errors: 0, Skipped: 0

[INFO] 
[INFO] --- maven-jar-plugin:2.4:jar (default-jar) @ maventutorial1 ---
[INFO] Building jar: /home/andrea/git/maven-java-console-application/mvntutorial1/target/maventutorial1-0.0.1-SNAPSHOT.jar
[INFO] 
[INFO] --- maven-assembly-plugin:2.5.5:single (default-cli) @ maventutorial1 ---
[INFO] Reading assembly descriptor: jar-with-dependencies
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 3.767 s
[INFO] Finished at: 2015-07-20T15:12:19+01:00
[INFO] Final Memory: 19M/155M
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-assembly-plugin:2.5.5:single (default-cli) on project maventutorial1: Error reading assemblies: Error locating assembly descriptor: jar-with-dependencies
[ERROR] 
[ERROR] [1] [INFO] Searching for file location: /home/andrea/git/maven-java-console-application/mvntutorial1/jar-with-dependencies
[ERROR] 
[ERROR] [2] [INFO] File: /home/andrea/git/maven-java-console-application/mvntutorial1/jar-with-dependencies does not exist.
[ERROR] 
[ERROR] [3] [INFO] File: /home/andrea/git/maven-java-console-application/mvntutorial1/jar-with-dependencies does not exist.
[ERROR] -> [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/MojoExecutionException

似乎找不到这个文件:/home/andrea/git/maven-java-console-application/mvntutorial1/jar-with-dependencies

但根据我对教程的理解，这不是一个配置文件，而是一个特定的 Maven 值，表示将所有 .jar 依赖项放入代表我的打包项目的最终目标 jar 文件中。

为什么会出现这个错误？我错过了什么？我该如何解决？

Answer 1

看来您没有正确使用assembly 插件。将插件条目更改为此:

<plugin>
  <artifactId>maven-assembly-plugin</artifactId>
  <configuration>
    <archive>
      <manifest>
        <mainClass>com.test.MainClassName</mainClass>
      </manifest>
    </archive>
    <descriptorRefs>
      <descriptorRef>jar-with-dependencies</descriptorRef>
    </descriptorRefs>
  </configuration>
  <executions>
    <execution>
      <id>make-assembly</id> 
      <phase>package</phase> <!-- packaging phase -->
      <goals>
        <goal>single</goal>
      </goals>
    </execution>
  </executions>
</plugin>

然后你只需要执行:clean install。这将在 target 目录中创建具有依赖项的 jar。您可以引用此链接中给出的这些示例:https://maven.apache.org/plugins/maven-assembly-plugin/examples/sharing-descriptors.html