Application context being loaded twice - Spring Boot - spring

Question

I have a fairly simple setup. A maven project with 3 modules : core/webapp/model. I'm using Spring boot to gear up my application. In webapp, i have a simple class WebappConfig as follows:
#Configuration
#EnableAutoConfiguration
#ComponentScan(excludeFilters = #ComponentScan.Filter(Configuration.class))
public class WebappConfig {
public static void main(String[] args) {
SpringApplication app = new SpringApplication(WebappConfig.class);
app.setAdditionalProfiles("dev");
app.run(args);
}
}
and few classes in core/model module. My container-application point is :
public class AbcdXml extends SpringBootServletInitializer {
#Override
protected SpringApplicationBuilder configure(SpringApplicationBuilder application) {
return application.sources(WebappConfig.class);
}
}
And no web.xml! My model's pom has following spring boot related dependency :
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
Core's pom.xml :
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-tomcat</artifactId>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-batch</artifactId>
</dependency>
Now running WebappConfig via Run as -> Java application works perfectly but i need to deploy the project as a war on tomcat7. Webapp's packaging is war. There is no tomcat provided jar's in lib except tomcat-jdbc and tomcat-tuli jar(Shouldn't be an issue?).
When i deploy my abcd.war, applicationcontext is getting loaded twice and result in following error stracktrace :
2014-06-27 11:06:08.445 INFO 23467 --- [ost-startStop-1] o.a.c.c.C.[.[localhost].[/abcd] : Initializing Spring embedded WebApplicationContext
2014-06-27 11:06:08.446 INFO 23467 --- [ost-startStop-1] o.s.web.context.ContextLoader : Root WebApplicationContext: initialization completed in 19046 ms
2014-06-27 11:06:21.308 INFO 23467 --- [ost-startStop-1] o.s.b.c.e.ServletRegistrationBean : Mapping servlet: 'dispatcherServlet' to [/]
2014-06-27 11:06:21.313 INFO 23467 --- [ost-startStop-1] o.s.b.c.embedded.FilterRegistrationBean : Mapping filter: 'errorPageFilter' to: [/*]
2014-06-27 11:06:21.314 INFO 23467 --- [ost-startStop-1] o.s.b.c.embedded.FilterRegistrationBean : Mapping filter: 'hiddenHttpMethodFilter' to: [/*]
2014-06-27 11:06:26.073 INFO 23467 --- [ost-startStop-1] j.LocalContainerEntityManagerFactoryBean : Building JPA container EntityManagerFactory for persistence unit 'default'
2014-06-27 11:06:26.127 INFO 23467 --- [ost-startStop-1] o.hibernate.jpa.internal.util.LogHelper : HHH000204: Processing PersistenceUnitInfo [
name: default
...]
2014-06-27 11:06:26.511 INFO 23467 --- [ost-startStop-1] org.hibernate.Version : HHH000412: Hibernate Core {4.3.1.Final}
2014-06-27 11:06:26.521 INFO 23467 --- [ost-startStop-1] org.hibernate.cfg.Environment : HHH000206: hibernate.properties not found
2014-06-27 11:06:26.527 INFO 23467 --- [ost-startStop-1] org.hibernate.cfg.Environment : HHH000021: Bytecode provider name : javassist
//some info messages from spring boot
2014-06-27 11:07:31.664 INFO 23467 --- [ost-startStop-1] o.s.w.s.handler.SimpleUrlHandlerMapping : Mapped URL path [/**/favicon.ico] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2014-06-27 11:07:33.095 INFO 23467 --- [ost-startStop-1] o.s.w.s.handler.SimpleUrlHandlerMapping : Mapped URL path [/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2014-06-27 11:07:33.096 INFO 23467 --- [ost-startStop-1] o.s.w.s.handler.SimpleUrlHandlerMapping : Mapped URL path [/webjars/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2014-06-27 11:07:36.080 INFO 23467 --- [ost-startStop-1] o.s.j.e.a.AnnotationMBeanExporter : Registering beans for JMX exposure on startup
2014-06-27 11:08:49.583 INFO 23467 --- [ost-startStop-1] o.s.boot.SpringApplication : Started application in 183.152 seconds (JVM running for 210.258)
2014-06-27 11:12:29.229 ERROR 23467 --- [ost-startStop-1] o.a.c.c.C.[.[localhost].[/abcd] : Exception sending context initialized event to listener instance of class org.springframework.web.context.ContextLoaderListener
java.lang.IllegalStateException: Cannot initialize context because there is already a root application context present - check whether you have multiple ContextLoader* definitions in your web.xml!
at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:277)
at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:106)
at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4937)
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5434)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:901)
at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:877)
at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:633)
at org.apache.catalina.startup.HostConfig.deployWAR(HostConfig.java:976)
at org.apache.catalina.startup.HostConfig$DeployWar.run(HostConfig.java:1653)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:334)
at java.util.concurrent.FutureTask.run(FutureTask.java:166)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
at java.lang.Thread.run(Thread.java:722)
There is no web.xml as i mentioned earlier.
Few interesting things that i can't figure out why :
After exploding the war, tomcat somehow create a ROOT folder with default web.xml[Must be Spring boot misconfiguration. How can i correct it? Pointers please?]
Even if i return same 'application' SpringApplicationBuilder in AbcdXml.java, i am facing the same issue of applicationcontext being loaded twice.
Thanks for your help!
EDIT 1:
Content of web.xml that is generated in ROOT folder :
<?xml version="1.0" encoding="ISO-8859-1"?>
<web-app xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_5.xsd" version="2.5">
</web-app>

Answer 1

If your app includes jersey-spring3 and you don't take steps to disable, it will try to create an ApplicationContext for you (helpful, not). There is a way to switch it off (in a WebApplicationInitializer):
servletContext.setInitParameter("contextConfigLocation", "<NONE>");
Or just use this: https://github.com/dsyer/spring-boot-jersey (include as a dependency).

Answer 2

In my case - I was having the same problem - seeing the Spring splash screen twice - It was because I had 2 classes that extended SpringBootServletInitializer. One was called SpringBootWebApplication and the other ServletInitializer. I just removed the ServletInitializer and it worked OK. Don't know why there were 2 classes - maybe because I got inspired from 2 different examples to assemble what I needed.

Answer 3

In my case the culprit was using Spring Boot 1.3.0.M4, along with Jersey 2.21. When I downgraded Spring Boot to 1.2.6.RELEASE the issue is gone.
The only thing I had to do was to explicitly override the following properties, as I needed spring 4.2.0 for Hibernate 5 support, and jackson 2.6.2 for JSR310 (java8 java.time) support:
<spring.version>4.2.0.RELEASE</spring.version>
<jackson.version>2.6.2</jackson.version>
EDIT: As of spring-boot 1.3.0.RELEASE, this bug still exists. See github

Answer 4

My main problem was my spring context was being loaded twice. As I printed every class's class loader I found that my Application was running twice. (i.e. when I debug in intellij after pressing F9 I was again landing up on same line i.e.
ConfigurableApplicationContext applicationContext = SpringApplication.run(ConfigAssignServer.class, args);
My problem was in pom.xml. I removed below dependency from my pom and it worked.
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-devtools</artifactId>
<scope>runtime</scope>
</dependency>
Please check for your dependencies. Hope it will help someone. Enjoy coding :)

Answer 5

I had the same issue
I have src>main>webapp>WEB-INF>web.xml has an entity to saying
<listener>
<listener-class>org.springframework.boot.legacy.context.web.SpringBootContextLoaderListener</listener-class>
</listener>
This is loading my context second time.
Comment it out and it will load only once.

Answer 6

I'm using Spring Boot 2.5.5 and experiencing the same issue but without error (WebApplicationContext) is being loaded twice along with scheduler calls are triggered as well too.
After debugging my application & Server(Tomcat v9.0.53) settings, I, myself able to solve the issue by deleting the "ServletInitializer.java" class which comes part of Spring initialiser project.
Now, all the issues resolved like schedulers are called once on predefined time along with the context loading.
Hope this resolves the issue.

Answer 7

Seems that "extends SpringBootServletInitializer" not work well with #SpringBootApplication in tomcat but when run with maven no duplicated beans is initialized so removing "extends SpringBootServletInitializer" from application main class solve the problem

Answer 8

In the Spring framework, usually for loading something like a global or root context, you club all the bean/resources shared by multiple servlet contexts.
Or loading a specific servlet context. Mvc-dispatcher config file is used to load config file, so you don't need to explicitly define it.
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>/WEB-INF/mvc-dispatcher-servlet.xml</param-value>
</context-param>
In your case, seems when you are running as a Java application, auto-detection of Mvc-dispatcher doesn't happen and you are able to execute the code successfully. Whereas when deployed it gets initiated both from root and mvc-dispatcher.
Use empty context: <context-param/>
I don’t see the contents of web.xml here, So I am throwing a quick suggestion from both perspectives.
Please try to delete dependency from the global/root context.
Or in case #EnableAutoConfiuguration is used, get rid of it.

Answer 9

#EnableAutoConfiuguration from the API says "Enable auto-configuration of the Spring Application Context, attempting to guess and configure beans that you are likely to need."
#ComponentScan would also instantiate the beans. IT will scan the packages, find and register the beans.
As you are using both these annotations, I guess that is why its loading twice.