about spring boot how to disable web environment correctly - spring-boot

Question

Spring boot non-web application, when start it has below error
Caused by: org.springframework.context.ApplicationContextException: Unable to start EmbeddedWebApplicationContext due to missing EmbeddedServletContainerFactory bean.
at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.getEmbeddedServletContainerFactory(EmbeddedWebApplicationContext.java:185) ~[spring-boot-1.3.5.RELEASE.jar:1.3.5.RELEASE]
Then I tried below manner
new SpringApplication().setWebEnvironment(false);
then start it still have above error.
Then tried
#SpringBootApplication(exclude={SpringDataWebAutoConfiguration.class})
but still have the same error.
At last I tried add below configuration in application.properties
spring.main.web-environment=false
this time it works.
Why the first two manner cannot work?

Answer 1

Starting from Spring Boot 2.0
-web(false)/setWebEnvironment(false) is deprecated and instead Web-Application-Type can be used to specify
Application Properties
spring.main.web-application-type=NONE
# REACTIVE, SERVLET
or SpringApplicationBuilder
#SpringBootApplication
public class SpringBootDisableWebEnvironmentApplication {
public static void main(String[] args) {
new SpringApplicationBuilder(SpringBootDisableWebEnvironmentApplication.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.
Courtesy: Another SO Answer

Answer 2

This answer is obsolete. Please note the other answer for Spring Boot 2.0
Original answer for Spring Boot 1.x:
The reason this config is not working because these are two different instances:
new SpringApplication().setWebEnvironment(false);
SpringApplication.run(SpringBootDisableWebEnvironmentApplication.class, args);
You are disabling setWebEnvironment(false) in new SpringApplication() object and calling static method run() on SpringApplication.run(...) which is different one.
I figured out 3 ways to do this:
#SpringBootApplication
public class SpringBootDisableWebEnvironmentApplication implements CommandLineRunner{
public static void main(String[] args) throws Exception {
// Method#1: Using SpringApplicationBuilder.
SpringApplication springApplication =
new SpringApplicationBuilder()
.sources(SpringBootDisableWebEnvironmentApplication.class)
.web(false)
.build();
springApplication.run(args);
//--------------------------------------------------------
// Method#2: Using SpringBootDisableWebEnvironmentApplication.
// SpringBootDisableWebEnvironmentApplication springBootDisableWebEnvironmentApplication =
// new SpringBootDisableWebEnvironmentApplication();
// springBootDisableWebEnvironmentApplication.run(args);
//--------------------------------------------------------
// Method#3: Using SpringApplication().
// SpringApplication springApplication = new SpringApplication();
// springApplication.setWebEnvironment(false);
//
// Set<Object> sources = new HashSet<>();
// sources.add(SpringBootDisableWebEnvironmentApplication.class);
// springApplication.setSources(sources);
// springApplication.run(args);
//--------------------------------------------------------
}
#Override
public void run(String... arg0) throws Exception {
System.out.println("Hello, Spring Boot gives many options ;)");
}
}
Here is the complete working Project.
And you don't need to exclude below config:
#SpringBootApplication(exclude = {EmbeddedServletContainerAutoConfiguration.class,
WebMvcAutoConfiguration.class})
Because you don't have spring-boot-starter-web dependency in your pom.xml
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>

Answer 3

As already noted in other answers the simplest solution is to add a property:
spring.main.web-application-type=NONE for Spring-boot 2.x
spring.main.web-environment=false for Spring-boot 1.x
But the simplest solution is NOT the best one, it's just quick&dirty.
Spring-boot has a lot of autoconfigurations that are triggered by the content of your classpath, so you probably have some unnecessary web-related dependency in your app.
I had a Spring-batch application that was giving
Unable to start ServletWebServerApplicationContext due to missing ServletWebServerFactory bean.
It was caused by the presence of javax.servlet-api in my POM. I removed it and the problem disappeared.

Answer 4

public static void main(String[] args) {
SpringApplication(Application.class)
.setWebApplicationType(WebApplicationType.NONE)
.run(args);
}
is another way instead of using the SpringApplicationBuilder.