Question

How do you check for Annotations when using IClassFile in Eclipse?

This doesnt seem to work classFile.getClass().isAnnotationPresent? Any help is appreciated.

The problem with using

for (final IClassFile classFile : classFiles) {
    IAnnotation[] annotations = classFile.getType().getAnnotations();

Is that I have to get All the Packages, then get the Class Files in that package then get the Annotations. It will require 3 loops. Is there a way to minimize this?

Answer 1

I would say that the easiest way for you to find annotations is through a triple loop, but it might be slightly faster (assuming you are looking for a specific annotation) to use a ‘SearchEngineinstead. Take a look at the source code for theorg.eclipse.jdt.internal.junit.launcher.JUnit4TestFinder` class. It looks for (source) classes annotated with @Test or @RunWith, which is similar to what you want to do, but for binary classes.

You would do something like this:

IJavaElement[] allPackagesToSearch = ...
SearchRequestor requestor = <implement the SearchRequestor abstract class and store all matches>

IJavaSearchScope scope= SearchEngine.createJavaSearchScope(binaryPackages, IJavaSearchScope.APPLICATION_LIBRARIES);
int matchRule= SearchPattern.R_EXACT_MATCH | SearchPattern.R_CASE_SENSITIVE;
SearchPattern runWithPattern= SearchPattern.createPattern("com.foo.MyAnnotation", IJavaSearchConstants.ANNOTATION_TYPE, IJavaSearchConstants.ANNOTATION_TYPE_REFERENCE, matchRule);
SearchParticipant[] searchParticipants= new SearchParticipant[] { SearchEngine.getDefaultSearchParticipant() };
new SearchEngine().search(annotationsPattern, searchParticipants, scope, requestor, new SubProgressMonitor(pm, 2));

It’s a bit of a mouthful, and to figure out how this works, I’d recommend reading the JavaDoc for SearchEngine, SearchPattern, and SearchRequestor.

If you want to find all annotations, then change the match rule, and instead of “com.foo.MyAnnotation”, use “*”.