How to find all the classes of a package in Java?

Yes, it is possible to find classes of a package in Java. You can Use reflections to find the same. 

Below is the code that helps you in determining the classes of a package using reflections. 

private Class<?>[] scanForTasks(String packageStr) 

{

        Reflections reflections = new Reflections((new ConfigurationBuilder()).setScanners(new Scanner[]

{new SubTypesScanner(), new TypeAnnotationsScanner()}).setUrls(ClasspathHelper.forPackage(packageStr, new ClassLoader[0])).filterInputsBy((new FilterBuilder()).includePackage(packageStr)));

        Set classes = reflections.getTypesAnnotatedWith(Task.class);

        Class[] taskArray = (Class[])classes.toArray(new Class[classes.size()]);

        return taskArray;

    }

}