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)
Is it possible to invoke the methods inside HelloMessageService class jar by an external application without calling in command line as “java -jar target/spring-boot-simple-1.0.jar “donald trump””
did you find out how it can be done ?
When I add this jar as a dependency in another web application(non springboot) , the application server cant start.
log written in main method is printing but log is not printing written in run(String… args) method.Kindly help to resolve.I am using spring boot log implementation.
This solution is great but how can we make it run faster, you just have to print a text and it takes about 4 seconds. Greetings and excuse my English
The real objective of Spring Boot is not to write very basic programs like hello world. Spring Boot is an overkill for such things. The real benefit of Spring boot is when you create large web or standalone apps.
thank yooooouuuuuu!!!!
Thanks
Thank you!
Hi, When I use spring-boot-starter-data-jpa, it stops working. Any suggestion?
Thank you for the post!
It really helped me get started with the spring boot command line app development.
hello mkyong could you please do a basic tutorial for Angular Spring security single page tutorial please, you are awesome