Over the years we have developed quite a few tactics to work with this, like starting the application in Unit @BeforeClass or even a JUnit run listener. This sort-of worked with old-style monolithic applications but it was usually a quite poor approach; there are all sorts of reasons for wanting to start slightly different permutations of your application, and why can't just spring be fast ?
As of spring 4.2 you can do this:
return new AnnotationConfigApplicationContext() {
@Override protected void resetCommonCaches() {
}
}
This will dramatically speed up creation of your subsequent spring contexts.
There are a couple of possible gotchas here; since this will re-use cached type information (cached in static scope) form your previous test run, much increasing the startup speed of a subsequent spring context within the same forked process. Moving all your IT's to a single project is always smart, since class loading and static initialization is the real killer in terms of startup time.
The method in AbstractApplicationContext (the base class) does this:
protected void resetCommonCaches() {
ReflectionUtils.clearCache();
ResolvableType.clearCache();
CachedIntrospectionResults.clearClassLoader(getClassLoader());
}
Happy hacking !
