Recently, I've reapackaged my java spring application to become a WAR file for deployment in tomcat. After some testing I noticed, that public static void main(String[] args)
is not executed. Some necessary initialization of my application is done in main
. Is there something like a main
method in a WAR file? What is the appropiate place in a WAR file to run some initialization?
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user1785730
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2You can specify in the `web.xml` file to execute a class on startup... – brso05 Apr 20 '15 at 12:49
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See also: http://stackoverflow.com/questions/8686507/how-to-add-a-hook-to-the-application-context-initialization-event – JimmyB Apr 20 '15 at 12:55
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This looks specific to Spring Boot - please update the tags, both answers posted at the moment don't take this fact into account. – kryger Apr 20 '15 at 13:58
3 Answers
11
You can add a listener to your web.xml
file:
<listener>
<description>Application startup and shutdown events</description>
<display-name>Test</display-name>
<listener-class>com.package.package.StartClass</listener-class>
</listener>
public class StartClass implements ServletContextListener {
@Override
public void contextDestroyed(ServletContextEvent servletContextEvent) {
//Context destroyed code here
}
@Override
public void contextInitialized(ServletContextEvent servletContextEvent)
{
//Context initialized code here
}
}
brso05
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@AaronDigulla you mean he may want to change the display name lol this is just an example... – brso05 Apr 20 '15 at 12:54
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I don't have a web.xml file, but do that with SpringBootServletInitializer. – user1785730 Apr 20 '15 at 12:56
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1@user1785730: Annotate your class with `@WebListener`. See http://docs.oracle.com/javaee/6/api/javax/servlet/annotation/WebListener.html – Aaron Digulla Apr 20 '15 at 14:20
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I work on a project, where web.xml has three listeners, and all of them do not belong to the project files - they are about some Spring classes. So, it is not a listener that points to the start class. – Gangnus Nov 05 '20 at 19:48
4
Well, You will have to create a listener in your web.xml that will be invoked by container at the time of startup.
<listener>
<listener-class>com.rdv.example.WebAppContext</listener-class>
</listener>
And this class will be implementing ServletContextListener
public class WebAppContext implements ServletContextListener {
public void contextInitialized(ServletContextEvent servletContextEvent) {
// Do your processing that you are trying to do in main method.
}
Raja
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1
I've found another way, that is independent of spring and tomcat: The @PostConstruct
annotation. In code:
@PostConstruct
public void init() {
// initialization code goes here
}
This method gets executed whether I run my application standalone or in tomcat.
For more information see How to call a method after bean initialization is complete? or Init method in Spring Controller (annotation version)
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user1785730
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