scan all the classes under a specific package recursively

ClassScanner.java

import java.io.File;
import java.net.URL;

public class ClassScanner {

	@FunctionalInterface
	public static interface ClassProcessor {
		void processClass( Class clazz ) ;
	}
	
	public static void scan( String packageName, ClassProcessor classProcessor ) {
		URL scannedUrl = Thread.currentThread().getContextClassLoader().getResource(packageName.replace( '.', '/'));
		if( scannedUrl != null ) {
			File scannedDir = new File(scannedUrl.getFile());
			for (File file : scannedDir.listFiles()) {
				scan( file, packageName, classProcessor );
			}
		}
	}
	
	private static void scan(File file, String packageName, ClassProcessor classProcessor) {
		String resource =  packageName + (packageName.isEmpty() ?"": ".") + file.getName();
		
		if( file.isDirectory() ) {
			for( File child: file.listFiles() ) {
				scan( child, resource, classProcessor );
			}
		} else if( file.getName().endsWith( ".class")) {
			String className = resource.substring( 0, resource.length() - ".class".length() );
			try {
				classProcessor.processClass( Class.forName( className  ));
			} catch (ClassNotFoundException e) {
			}
		}
		
	}
	
}