关于picocli和GraalVM本机图像的问题

Question

我正在尝试构建一个Java应用程序，该应用程序将使用GraalVM提供的本地映像构建到Linux命令行应用程序中。我有以下代码：

@CommandLine.Command(
        name = "my-application",
        mixinStandardHelpOptions = true,
        helpCommand = true,
        version = "my-application 1.0",
        description = "My file manipulation application."
)
public class MyApplication implements Callable<Integer> {

    private static final ObjectMapper OBJECT_MAPPER = new ObjectMapper(new YAMLFactory()
            .enable(YAMLGenerator.Feature.LITERAL_BLOCK_STYLE)
            .disable(YAMLGenerator.Feature.WRITE_DOC_START_MARKER)
    );

    @CommandLine.Parameters(index = "0", description = "The source file.")
    private File sourceFile;

    @CommandLine.Parameters(index = "1", description = "The target files.")
    private List<File> targetFiles;

    @CommandLine.Option(names = {"-env", "--environment"}, defaultValue = "TEST")
    private Environment environment; // TEST or PROD

    @CommandLine.Spec CommandLine.Model.CommandSpec spec;

    public static void main(String[] args) {
        int exitCode = new CommandLine(new MyApplication()).execute(args);
        System.exit(exitCode);
    }

    @Override
    public Integer call() throws Exception {
        spec.commandLine()
                .getOut()
                .println("Starting my-application tool execution...");

        // Some file manipulation using Jackson.

        spec.commandLine().getOut().println("Execution finished successfully.");

        return 0;
    }

我用maven包构建JAR，这个jar有所有需要的依赖项。然后，我使用以下方法构建本机应用程序：

native-image -jar my-application-1.0-SNAPSHOT-jar-with-dependencies.jar -H:+ReportExceptionStackTraces --no-fallback

在运行应用程序时：

./my-application-1.0-SNAPSHOT-jar-with-dependencies inputfile.txt outputfile1.txt outputfile2.txt

我得到以下错误：

Exception in thread "main" picocli.CommandLine$InitializationException: picocli.CommandLine$AutoHelpMixin@62037019 is not a command: it has no @Command, @Option, @Parameters or @Unmatched annotations
    at picocli.CommandLine$Model$CommandReflection.validateCommandSpec(CommandLine.java:11680)
    at picocli.CommandLine$Model$CommandReflection.extractCommandSpec(CommandLine.java:11510)
    at picocli.CommandLine$Model$CommandSpec.forAnnotatedObject(CommandLine.java:6236)
    at picocli.CommandLine$Model$CommandSpec.mixinStandardHelpOptions(CommandLine.java:7220)
    at picocli.CommandLine$Model$CommandReflection.extractCommandSpec(CommandLine.java:11505)
    at picocli.CommandLine$Model$CommandSpec.forAnnotatedObject(CommandLine.java:6236)
    at picocli.CommandLine.<init>(CommandLine.java:227)
    at picocli.CommandLine.<init>(CommandLine.java:221)
    at picocli.CommandLine.<init>(CommandLine.java:196)
    at com.test.MyApplication.main(MyApplication.java:42)

当我通过IntelliJ或一个简单的java -jar命令运行它时，应用程序工作得很好。

我尝试了一些东西，比如移除mixinStandardHelpOptions和helpCommand，但是我开始收到一些错误，比如“索引0中的非匹配参数”或规范中的NullPointer (用于输出输出)。

在引入picocli之前，我能够成功地运行本机应用程序并使用ObjectMapper操作文件，因此我相信打包和图像构建过程是正确的。

试着跟着这里的提示：

https://github.com/remkop/picocli/issues/631

但我不知道该怎么做，试着添加了这样的东西

@Reflections({
        @Reflection(scanClass = CommandLine.Mixin.class),
        @Reflection(scanClass = CommandLine.HelpCommand.class)
})

但什么都没变。

如能提供任何帮助，将不胜感激:)

Answer 1

我刚刚发现我失去了一个依赖关系：

<!-- https://mvnrepository.com/artifact/info.picocli/picocli-codegen -->
<dependency>
    <groupId>info.picocli</groupId>
    <artifactId>picocli-codegen</artifactId>
    <version>4.6.3</version>
</dependency>

有关详细信息，请参阅：

https://www.infoq.com/articles/java-native-cli-graalvm-picocli/