In Spring Boot, to create a non-web application, implements CommandLineRunner and override the run method, for example :


import org.springframework.boot.CommandLineRunner;

@SpringBootApplication
public class SpringBootConsoleApplication implements CommandLineRunner {

    public static void main(String[] args) throws Exception {

        SpringApplication.run(SpringBootConsoleApplication.class, args);
		
    }

    //access command line arguments
    @Override
    public void run(String... args) throws Exception {
	
        //do something
		
    }
}

1. Project Structure

A standard Maven project structure.

2. Project Dependency

Only spring-boot-starter

pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0
  http://maven.apache.org/maven-v4_0_0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.mkyong</groupId>
    <artifactId>spring-boot-simple</artifactId>
    <packaging>jar</packaging>
    <version>1.0</version>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.5.1.RELEASE</version>
    </parent>

    <properties>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>

    </dependencies>

    <build>
        <plugins>
            <!-- Package as an executable jar/war -->
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

3. Spring

3.1 A service to return a message.

HelloMessageService.java

package com.mkyong.service;

import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Service;

@Service
public class HelloMessageService {

    @Value("${name:unknown}")
    private String name;

    public String getMessage() {
        return getMessage(name);
    }

    public String getMessage(String name) {
        return "Hello " + name;
    }

}

application.properties

name=mkyong

3.2 CommandLineRunner example. If you run this Spring Boot, the run method will be the entry point.

SpringBootConsoleApplication.java

package com.mkyong;

import com.mkyong.service.HelloMessageService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.Banner;
import org.springframework.boot.CommandLineRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

import static java.lang.System.exit;

@SpringBootApplication
public class SpringBootConsoleApplication implements CommandLineRunner {

    @Autowired
    private HelloMessageService helloService;

    public static void main(String[] args) throws Exception {

        //disabled banner, don't want to see the spring logo
        SpringApplication app = new SpringApplication(SpringBootConsoleApplication.class);
        app.setBannerMode(Banner.Mode.OFF);
        app.run(args);

    }

	// Put your logic here.
    @Override
    public void run(String... args) throws Exception {

        if (args.length > 0) {
            System.out.println(helloService.getMessage(args[0].toString()));
        } else {
            System.out.println(helloService.getMessage());
        }

        exit(0);
    }
}

4. DEMO

Package and run it.


## Go to project directory
## package it
$ mvn package

$ java -jar target/spring-boot-simple-1.0.jar
Hello mkyong

$ java -jar target/spring-boot-simple-1.0.jar "donald trump"
Hello donald trump

Download Source Code

Download – spring-boot-non-web-example.zip (5 KB)

References

  1. CommandLineRunner JavaDoc