Description Matt Chapman 2005-08-23 11:13:42 EDT

With AJDT (AspectJ dev tools) installed users are reporting exceptions like this:
Caused by: java.lang.StringIndexOutOfBoundsException: String index out of range: -1
at java.lang.String.substring(String.java:1768)
at
org.eclipse.jdt.internal.core.util.Util.getNameWithoutJavaLikeExtension(Util.java:839)
at
org.eclipse.jdt.internal.core.search.matching.PossibleMatch.getQualifiedName(PossibleMatch.java:101)
at
org.eclipse.jdt.internal.core.search.matching.PossibleMatch.<init>(PossibleMatch.java:41)
at
org.eclipse.jdt.internal.core.search.matching.MatchLocator.locateMatches(MatchLocator.java:1097)
at
org.eclipse.jdt.internal.core.search.JavaSearchParticipant.locateMatches(JavaSearchParticipant.java:94)
at
org.eclipse.jdt.internal.core.search.BasicSearchEngine.findMatches(BasicSearchEngine.java:208)
at
org.eclipse.jdt.internal.core.search.BasicSearchEngine.search(BasicSearchEngine.java:424)
at org.eclipse.jdt.core.search.SearchEngine.search(SearchEngine.java:532)
at
org.eclipse.jdt.internal.corext.refactoring.RefactoringSearchEngine.findAffectedCompilationUnits(RefactoringSearchEngine.java:72)
at
org.eclipse.jdt.internal.corext.refactoring.rename.RenameTypeProcessor.checkConflictingTypes(RenameTypeProcessor.java:593)

See AJDT bug 98547 for more details of the scenarios in which this occurs. Note
that the problem can happen in regular Java projects, but of course only with
AJDT in the picture.

This happens because AJDT defines subtypes of CompilationUnit for aspects
contained in .aj files.

Util.getNameWithoutJavaLikeExtension (in the "model" source folder)
currently looks like this:

	/**
	 * Returns the substring of the given file name, ending at the start of a Java
like extension.
	 */
	public static String getNameWithoutJavaLikeExtension(String fileName) {
		int index = indexOfJavaLikeExtension(fileName);
		return fileName.substring(0, index);
	}

So it is getting called with a name like "MyAspect.aj", and the
indexOfJavaLikeExtension() method is then returning -1, resulting in the out of
bounds exception on the next line.

The fix is therefore to simply make the method more robust, such as:

	/**
	 * Returns the substring of the given file name, ending at the start of a
	 * Java like extension. The entire file name is returned if it doesn't end
	 * with a Java like extension.
	 */
	public static String getNameWithoutJavaLikeExtension(String fileName) {
		int index = indexOfJavaLikeExtension(fileName);
		if (index == -1) {
			return fileName;
		}
		return fileName.substring(0, index);
	}