[java] Spring Boot without the web server

I have a simple Spring Boot application that gets messages from a JMS queue and saves some data to a log file, but does not need a web server. Is there any way of starting Spring Boot without the web server?

Similar to @nayun oh answer above, but for older versions of Spring, use this code:

SpringApplication application = new SpringApplication(DemoApplication.class);
application.setApplicationContextClass(AnnotationConfigApplicationContext.class);
application.run(args);

The simplest solution. in your application.properties file. add the following property as mentioned by a previous answer:

spring.main.web-environment=false

For version 2.0.0 of Spring boot starter, use the following property :

spring.main.web-application-type=none

For documentation on all properties use this link : https://docs.spring.io/spring-boot/docs/current/reference/html/common-application-properties.html

You can use the spring-boot-starter dependency. This will not have the web stuff.

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

Spring boot has many starters, some starters have an embedded web server, some don't. The following have the embedded web server:

spring-boot-starter-web
spring-boot-starter-data-jpa
spring-boot-starter-jetty
spring-boot-starter-tomcat
spring-boot-starter-jdbc
spring-boot-starter-data-rest
...

Pick the one that meets your requirements and that does not have server support.

I only need to make restful json api request in my spring application, so the starter I need is

spring-boot-starter-json

which provide RestTemplate and jackson for me to use.

For Spring boot v2.1.3.RELEASE, just add the follow properties into application.propertes:

spring.main.web-application-type=none

Remove folowing dependancy on your pom file will work for me

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

For Kotling here is what I used lately:

// src/main/com.blabla/ShellApplication.kt

/**
 * Main entry point for the shell application.
 */
@SpringBootApplication
public class ShellApplication : CommandLineRunner {
    companion object {
        @JvmStatic
        fun main(args: Array<String>) {
            val application = SpringApplication(ShellApplication::class.java)
            application.webApplicationType = WebApplicationType.NONE
            application.run(*args);
        }
    }

    override fun run(vararg args: String?) {}
}

// src/main/com.blabla/command/CustomCommand.kt

@ShellComponent
public class CustomCommand {
    private val logger = KotlinLogging.logger {}

    @ShellMethod("Import, create and update data from CSV")
    public fun importCsv(@ShellOption() file: String) {
        logger.info("Hi")
    }
}

And everything boot normally ending up with a shell with my custom command available.

if you want to run spring boot without a servlet container, but with one on the classpath (e.g. for tests), use the following, as described in the spring boot documentation:

@Configuration
@EnableAutoConfiguration
public class MyClass{
    public static void main(String[] args) throws JAXBException {
                 SpringApplication app = new SpringApplication(MyClass.class);
         app.setWebEnvironment(false); //<<<<<<<<<
         ConfigurableApplicationContext ctx = app.run(args);
    }
}

also, I just stumbled across this property:

spring.main.web-environment=false

You can create something like this:

@SpringBootApplication
public class Application {
  public static void main(String[] args) {
    new SpringApplicationBuilder(Application.class).web(false).run(args);
  }
}

And

@Component
public class CommandLiner implements CommandLineRunner {

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

}

The dependency is still there though but not used.

Use this code.

SpringApplication application = new SpringApplication(DemoApplication.class);
application.setWebApplicationType(WebApplicationType.NONE);
application.run(args);

If you need web functionality in your application (like org.springframework.web.client.RestTemplate for REST calls) but you don't want to start a TOMCAT server, just exclude it in the POM:

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
    <exclusions>
        <exclusion>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-tomcat</artifactId>
        </exclusion>
    </exclusions>
</dependency>

• Through program :

  ConfigurableApplicationContext ctx =  new  SpringApplicationBuilder(YourApplicationMain.class)
  .web(WebApplicationType.NONE)
  .run(args);
  

• Through application.properties file :

  spring.main.web-environment=false 
  

• Through application.yml file :

  spring:
   main:
    web-environment:false
  

In Spring boot, Spring Web dependency provides an embedded Apache Tomcat web server. If you remove spring-boot-starter-web dependency in the pom.xml then it doesn't provide an embedded web server.

remove the following dependency

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

Spring Boot 2.x

• Application Properties

  spring.main.web-application-type=NONE 
  # REACTIVE, SERVLET
  

• or SpringApplicationBuilder

  @SpringBootApplication
  public class MyApplication {
  
      public static void main(String[] args) {
          new SpringApplicationBuilder(MyApplication.class)
              .web(WebApplicationType.NONE) // .REACTIVE, .SERVLET
              .run(args);
     }
  }
  

Where WebApplicationType:

• NONE - The application should not run as a web application and should not start an embedded web server.
• REACTIVE - The application should run as a reactive web application and should start an embedded reactive web server.
• SERVLET - The application should run as a servlet-based web application and should start an embedded servlet web server.

If you want to use one of the "Getting Started" templates from spring.io site, but you don't need any of the servlet-related stuff that comes with the "default" ("gs/spring-boot") template, you can try the scheduling-tasks template (whose pom* contains spring-boot-starter etc) instead:

https://spring.io/guides/gs/scheduling-tasks/

That gives you Spring Boot, and the app runs as a standalone (no servlets or spring-webmvc etc are included in the pom). Which is what you wanted (though you may need to add some JMS-specific stuff, as someone else points out already).

[* I'm using Maven, but assume that a Gradle build will work similarly].