java - 在线程中访问 springboot 中的命令行参数

Question

我运行我的 Spring Boot 应用程序

mvn spring-boot:run -Dspring-boot.run.arguments="test1, test2, test3"

我的可运行程序中需要这 3 个参数。如何在 Compressor 可运行类中访问它们？它打印 null。

@Configuration
    public class MultiThreadConfig {

        @Bean
        public TaskExecutor taskExecutor() {
            return new SimpleAsyncTaskExecutor(); // Or use another one of your liking
        }

        @Bean
        public CommandLineRunner schedulingRunner(TaskExecutor executor) {
            return new CommandLineRunner() {
                public void run(String[] args) throws Exception {
                    executor.execute(new Compressor(args));
                }
            };
        }
    }



public class Compressor implements Runnable {

    @Autowired
    ApplicationArguments appArgs;

    String[] args;

    // Constructor
    public Compressor(String[] args) {
        //Initialization of atributes
    }

    @Override
    public void run() {
        System.out.println("COMPRESSOR YO");
        System.out.println(Arrays.toString(args));
        System.out.println(appArgs);
    }
}

Answer 1

正如 Jesper 指出的，您正在使用 new 关键字自己创建 Compressor 对象，因此 ApplicationArguments 不会 Autowiring ，因为 Compressor 的此实例不是由 Spring 管理的。解决方案是为Compressor对象创建一个bean，并让Spring管理它。例如:

@Configuration
public class MultiThreadConfig {

    @Bean
    public TaskExecutor taskExecutor() {
        return new SimpleAsyncTaskExecutor(); // Or use another one of your liking
    }


    @Bean
    public Compressor compressor(ApplicationArguments applicationArguments) {
        return Compressor(applicationArguments);
    }

    @Bean
    public CommandLineRunner schedulingRunner(TaskExecutor executor, Compressor compressor) {
        return new CommandLineRunner() {
            public void run(String[] args) throws Exception {
                executor.execute(compressor);
            }
        };
    }
}

和

public class Compressor implements Runnable {

    private final ApplicationArguments appArgs;
    private final String[] args;

    @Autowired
    public Compressor(ApplicationArguments applicationArguments) {
        appArgs = applicationArguments;
        args = applicationArguments.getSourceArgs();
    }

    @Override
    public void run() {
        System.out.println("COMPRESSOR YO");
        System.out.println(Arrays.toString(args));
    }
}

请注意，我使用构造函数注入(inject)而不是字段注入(inject)，这通常是更好的选择。

如果您不想在配置中创建 bean，您还可以使用 Spring 构造型标记 Compressor:

@Component
public class Compressor implements Runnable {

    private final ApplicationArguments appArgs;
    private final String[] args;

    public Compressor(ApplicationArguments applicationArguments) {
        appArgs = applicationArguments;
        args = applicationArguments.getSourceArgs();
    }
    //...
}

并在您的配置中使用它的实例，如上所示:

@Bean
public CommandLineRunner schedulingRunner(TaskExecutor executor, Compressor compressor) {
    //...
}