Spring boot 和 maven exec 插件问题

使用Spring Boot和Maven Exec插件进行Java应用程序开发

xml
   
      org.springframework.boot
      spring-boot-starter
      2.5.0
   

java
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
public class App {
   public static void main(String[] args) {
      SpringApplication.run(App.class, args);
   }
}

xml
   
      
         org.codehaus.mojo
         exec-maven-plugin
         3.0.0
         
            
               exec
               test
               
                  java
               
            
         
         
            com.example.App
         
      
   

java
public class HelloWorld {
   public static void main(String[] args) {
      System.out.println("Hello, World!");
   }
}

java
public class Greeting {
   public String getGreeting() {
      return "Hello, World!";
   }
}

java
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
public class App {
   public static void main(String[] args) {
      Greeting greeting = new Greeting();
      System.out.println(greeting.getGreeting());
   }
}

mvn exec:java