Maven webstart 插件找不到依赖项

Question

希望有人能帮助我解决这个奇怪的问题。我正在尝试运行 webstart 插件，但它似乎无法在正在生成的 jar 中找到主类。 pom 非常简单，并且类 Test 存在，并且正在编译并放入 jar 中。有人可以指出我正确的方向吗？

<project>
  <modelVersion>4.0.0</modelVersion>
  <name>Desktop Components</name>
  <groupId>com.test</groupId>
  <artifactId>test</artifactId>
  <version>1.0</version>
  <packaging>jar</packaging>
  <build>
    <plugins>
      <plugin>
        <groupId>org.codehaus.mojo.webstart</groupId>
        <artifactId>webstart-maven-plugin</artifactId>
        <executions>
          <execution>
            <phase>process-resources</phase>
            <goals>
              <goal>jnlp-download-servlet</goal>
            </goals>
          </execution>
        </executions>

        <configuration>
          <jnlpFiles>
            <jnlpFile>
              <jarResources>
                <jarResource>
                  <groupId>com.test</groupId>
                  <artifactId>test</artifactId>
                  <version>1.0</version>
                  <mainClass>Test</mainClass>
                </jarResource>
              </jarResources>
            </jnlpFile>
          </jnlpFiles>
        </configuration>
      </plugin>
    </plugins>
  </build>
</project>

以下是 Maven 跟踪：

C:\TEMP\webstart-test>mvn webstart:jnlp –e
+ Error stacktraces are turned on.
[INFO] Scanning for projects...
[INFO] ------------------------------------------------------------------------
[INFO] Building Desktop Components
[INFO]    task-segment: [webstart:jnlp] (aggregator-style)
[INFO] ------------------------------------------------------------------------
[INFO] Preparing webstart:jnlp
[INFO] ------------------------------------------------------------------------
[INFO] Building Desktop Components
[INFO] ------------------------------------------------------------------------
[INFO] [resources:resources {execution: default-resources}]
[WARNING] Using platform encoding (Cp1252 actually) to copy filtered resources, i.e. build is platform dependent!
[INFO] skip non existing resourceDirectory C:\TEMP\webstart-test\src\main\resources
[INFO] [webstart:jnlp-download-servlet {execution: default}]
[INFO] No templateFilename found for launch2.jnlp. Will use the default template.
[INFO] No resources found in C:\TEMP\webstart-test\src\main\jnlp\resources
Downloading: http://repo1.maven.org/maven2/com/test/test/1.0/test-1.0.pom
[INFO] Unable to find resource 'com.test:test:pom:1.0' in repository central (http://repo1.maven.org/maven2)
No template specified Using default one.

***** Webstart JAR URL: jar:file:/C:/apache-maven-2.2.1/repo/org/codehaus/mojo/webstart/webstart-maven-plugin/1.0-alpha-2/webstart-maven-plugin-1.0-alpha-2.jar!
/
[INFO] [compiler:compile {execution: default-compile}]
[INFO] Nothing to compile - all classes are up to date
[INFO] [resources:testResources {execution: default-testResources}]
[WARNING] Using platform encoding (Cp1252 actually) to copy filtered resources, i.e. build is platform dependent!
[INFO] skip non existing resourceDirectory C:\TEMP\webstart-test\src\test\resources
[INFO] [compiler:testCompile {execution: default-testCompile}]
[INFO] No sources to compile
[INFO] [surefire:test {execution: default-test}]
[INFO] No tests to run.
[INFO] [jar:jar {execution: default-jar}]
[INFO] Building jar: C:\TEMP\webstart-test\target\test-1.0.jar
[INFO] [webstart:jnlp {execution: default-cli}]
[INFO] No resources found in C:\TEMP\webstart-test\src\main\jnlp\resources
[INFO] ------------------------------------------------------------------------
[ERROR] BUILD ERROR
[INFO] ------------------------------------------------------------------------
[INFO] Failure to run the plugin:
[INFO] ------------------------------------------------------------------------
[INFO] Trace

跟踪

org.apache.maven.lifecycle.LifecycleExecutionException: Failure to run the plugin:
        at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoals(DefaultLifecycleExecutor.java:719)
        at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeStandaloneGoal(DefaultLifecycleExecutor.java:569)
        at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoal(DefaultLifecycleExecutor.java:539)
        at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoalAndHandleFailures(DefaultLifecycleExecutor.java:387)
        at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeTaskSegments(DefaultLifecycleExecutor.java:284)
        at org.apache.maven.lifecycle.DefaultLifecycleExecutor.execute(DefaultLifecycleExecutor.java:180)
        at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:328)
        at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:138)
        at org.apache.maven.cli.MavenCli.main(MavenCli.java:362)
        at org.apache.maven.cli.compat.CompatibleMain.main(CompatibleMain.java:60)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:592)
        at org.codehaus.classworlds.Launcher.launchEnhanced(Launcher.java:315)
        at org.codehaus.classworlds.Launcher.launch(Launcher.java:255)
        at org.codehaus.classworlds.Launcher.mainWithExitCode(Launcher.java:430)
        at org.codehaus.classworlds.Launcher.main(Launcher.java:375)

现在是由跟踪引起的

Caused by: org.apache.maven.plugin.MojoExecutionException: Failure to run the plugin:
        at org.codehaus.mojo.webstart.AbstractJnlpMojo.execute(AbstractJnlpMojo.java:289)
        at org.apache.maven.plugin.DefaultPluginManager.executeMojo(DefaultPluginManager.java:490)
        at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoals(DefaultLifecycleExecutor.java:694)
        ... 17 more

Caused by: java.lang.NullPointerException
        at org.codehaus.mojo.webstart.AbstractJnlpMojo.execute(AbstractJnlpMojo.java:214)
        ... 19 more

，最后是 Maven 跟踪

[INFO] ------------------------------------------------------------------------
[INFO] Total time: 9 seconds
[INFO] Finished at: Fri Nov 13 11:16:54 GMT 2009
[INFO] Final Memory: 12M/22M
[INFO] ------------------------------------------------------------------------

Answer 1

这是 JNLP 的 mainClass 的问题

你需要这样的东西

<configuration>
   <jnlp>
      <mainClass>com.test.Test</mainClass>
   </jnlp>
<configuration>

Answer 2

我确信这对您来说不再是问题，因为这个问题已经存在一年了。但是，为了完整起见......

我编辑了问题以使其可读。这向我们表明错误位于 AbstractJnlpMojo 的第 214 行。 查看最新版本源码第214行（上面的根本原因），我们可以看到这是因为你没有为JNLP指定main方法文件。

JNLP 不需要 jar 资源中刚刚指定的 main 方法类。 JNLP 标签中也需要它，如下所示。

    <configuration>
      <jnlp>
        <mainClass>com.test.Test</mainClass>
      </jnlp>
    </configuration>

由于代码已更改，如果您今天执行此操作，您将收到以下异常（更具可读性）：

org.apache.maven.plugin.MojoExecutionException: 
  didn't find artifact with main class: null. Did you specify it? 

Answer 3

为了解决这个问题：

未找到主类的工件：null。你指定了吗？

我必须创建一个多模块 Maven 项目，如下所示：

• base-project
  • 主应用
  • 网络启动

然后在 webstart 的 pom 文件中，我将 main-app 作为依赖项包含在内。最后，从 webstart 目录中运行 mvn webstart:jnlp 。

Answer 4

我不认为它是你的依赖项没有找到，而是 C:\TEMP\webstart-test\src\main\jnlp\resources 中的一些文件，例如你的 jnlp 文件的 Velocity 模板？