java - 基于 Spring Boot 控制台的应用程序如何工作？

Question

如果我正在开发一个相当简单的基于 Spring Boot 控制台的应用程序，我不确定主要执行代码的位置。我应该将它放在 public static void main(String[] args) 方法中，还是让主应用程序类实现 CommandLineRunner 接口(interface)并将代码放在 run(String... args) 方法中？

我将使用一个示例作为上下文。假设我有以下 [基本] 应用程序(编码为接口(interface)，Spring 风格):

Application.java

public class Application {

  @Autowired
  private GreeterService greeterService;

  public static void main(String[] args) {
    // ******
    // *** Where do I place the following line of code
    // *** in a Spring Boot version of this application?
    // ******
    System.out.println(greeterService.greet(args));
  }
}

GreeterService.java(接口(interface))

public interface GreeterService {
  String greet(String[] tokens);
}

GreeterServiceImpl.java(实现类)

@Service
public class GreeterServiceImpl implements GreeterService {
  public String greet(String[] tokens) {

    String defaultMessage = "hello world";

    if (args == null || args.length == 0) {
      return defaultMessage;
    }

    StringBuilder message = new StringBuilder();
    for (String token : tokens) {
      if (token == null) continue;
      message.append(token).append('-');
    }

    return message.length() > 0 ? message.toString() : defaultMessage;
  }
}

Application.java 的等效 Spring Boot 版本大致如下:GreeterServiceImpl.java(实现类)

@EnableAutoConfiguration
public class Application
    // *** Should I bother to implement this interface for this simple app?
    implements CommandLineRunner {

    @Autowired
    private GreeterService greeterService;

    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
        System.out.println(greeterService.greet(args)); // here?
    }

    // Only if I implement the CommandLineRunner interface...
    public void run(String... args) throws Exception {
        System.out.println(greeterService.greet(args)); // or here?
    }
}

Answer 1

你应该有一个标准的加载器:

@SpringBootApplication
public class MyDemoApplication {
    public static void main(String[] args) {
        SpringApplication.run(MyDemoApplication.class, args);
    }
}

并使用@Component注解实现一个CommandLineRunner接口(interface)

    @Component
    public class MyRunner implements CommandLineRunner {

       @Override    
       public void run(String... args) throws Exception {

      }
   }

@EnableAutoConfiguration 将执行通常的 SpringBoot 魔法。

更新:

正如@jeton 建议的那样，最新的 Springboot 实现了一个直:

spring.main.web-application-type=none
spring.main.banner-mode=off

见 docs at 72.2