java - 我想创建非 Web Spring Boot 应用程序

Question

我想创建非 Web Spring Boot 应用程序。但我收到以下错误

@SpringBootApplication
public class TaskApplication implements CommandLineRunner {

    @Autowired
    TaskService taskService;

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

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

        taskService.print();

    }

}

public interface TaskService  {

    public void print();
}



public class TaskServiceImpl implements TaskService {

    @Override
    public void print() {
        System.out.println("sam");
    }

}

属性:

spring.datasource.url=jdbc:mysql://localhost:3306/demo?verifyServerCertificate=false&useSSL=false&requireSSL=false&allowPublicKeyRetrieval=true
spring.datasource.username=root
spring.datasource.password=root@123
spring.datasource.driverClassName=com.mysql.cj.jdbc.Driver
spring.jpa.show-sql=true
spring.jpa.hibernate.dialect=org.hibernate.dialect.MySQLDialect
spring.main.allow-bean-definition-overriding=true
##spring.jpa.hibernate.ddl-auto=update

错误

***************************
APPLICATION FAILED TO START
***************************

Description:

Field taskService in com.example.task.TaskApplication required a bean of type 'com.example.task.service.TaskService' that could not be found.

The injection point has the following annotations:
    - @org.springframework.beans.factory.annotation.Autowired(required=true)

行动:

Consider defining a bean of type 'com.example.task.service.TaskService' in your configuration.

Answer 1

@M。 Deinum 已经在评论中解释了。您需要使用 @Service 或 @Component 注解来标记类，以创建 spring bean 并在 main 方法中 Autowiring 。

    // mark it with service annotation.
    @Service
    public class TaskServiceImpl implements TaskService {

        @Override
        public void print() {
            System.out.println("sam");
        }

    }

要了解为什么需要这些注释，请访问此链接:@Component vs @Repository and @Service in Spring