SpringBoot and use / load a dynamic "applicationContext.xml" instead of hard coded one - spring-boot

Question

I've seen a hundred examples of this:
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.ImportResource;
#SpringBootApplication
#ImportResource("classpath:applicationContext.xml")
public class MySpringBootApplication {
public static void main(String[] args) {
SpringApplication.run(MySpringBootApplication.class, args);
}
}
And I have been on a rabbit trail for many hours now.
I am building a framework....and I need load (a handful of dependencies, not all of them...) from the xml dependency injection file (aka, "beans") :
applicationContext.xml
and I need to name to be dynamic, not hard coded.
String myValue = "DefaultEnvVarValue";
String envValue = System.getenv("MYENVVARIABLENAME");
if (null != envValue )
{
myValue=envValue;
}
String topLevelAppContextFileName = "applicationContext." + myValue + ".xml";
Without springboot, I would do this:
ApplicationContext context = new ClassPathXmlApplicationContext(topLevelAppContextFileName);
Is there a way to pull this off with SpringBoot?
I found PropertySourcesPlaceholderConfigurer for property files, but cannot find anything for the dependency injection.
Sidenote:
Before I get a "xml bad" comment, most of my dependencies are annotation based. But I'm making a framework for others to use, and therefore I need a handful of them to be xml-driven.....aka, I have a legit reason to have some of the DI be xml driven.

Answer 1

This could work -
Config
public class DemoApplicationContextInitializer implements ApplicationContextInitializer<ConfigurableApplicationContext> {
#Override
public void initialize(ConfigurableApplicationContext ac) {
ac = new ClassPathXmlApplicationContext(topLevelAppContextFileName);
}
}
Main
public static void main(String args[]) {
new SpringApplicationBuilder(Application.class)
.initializers(new DemoApplicationContextInitializer())
.run(
}

Answer 2

For future readers, I ended up doing this:
#SpringBootApplication
#ImportResource({"classpath*:applicationContext.xml"})
public class MySpringBootApplication {
public static void main(String[] args) {
try {
URL resource = MySpringBootApplication.class.getResource("/applicationContext.xml");
if (null == resource || StringUtils.isBlank(resource.getPath())) {
throw new FileNotFoundException("applicationContext.xml not found. The entry dependency injection file must be applicationContext.xml");
}
org.springframework.context.ConfigurableApplicationContext applicationContext = SpringApplication.run(MySpringBootApplication.class, args);
And then I put the "dynamic" part in the inside applicationContext.xml file.
Note the ":" delimiter that will allow a default value if the environment variable does not exist.
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:util="http://www.springframework.org/schema/util"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context.xsd
http://www.springframework.org/schema/util
http://www.springframework.org/schema/util/spring-util.xsd">
<import resource="projectContext.${MYENVVARIABLENAME:DefaultEnvVarValue}.xml"/>
That was simpler to implement, even though I technically have 2 files, instead of one.
So if the environment variable does not exist, it will default to importing the second file called:
projectContext.DefaultEnvVarValue.xml