The @HandlesTypes annotation in Java is used to specify the types that a servlet container should discover at startup. Here are a few examples of how to use the @HandlesTypes annotation:

1. Discovering all subclasses of a particular class:

@HandlesTypes(Fruit.class)
public class MyServletContainerInitializer implements ServletContainerInitializer {
    @Override
    public void onStartup(Set<Class<?>> classes, ServletContext ctx) throws ServletException {
        for (Class<?> cls : classes) {
            if (Fruit.class.isAssignableFrom(cls)) {
                // Handle the class as a fruit
            }
        }
    }
}

In this example, the @HandlesTypes annotation is used to discover all subclasses of the Fruit class. The onStartup method of the ServletContainerInitializer is then called with a set of classes that match the specified criteria. The code then loops through the set of classes and handles each one that is a subclass of Fruit.

2. Discovering all classes that implement a particular interface:

@HandlesTypes(Fruit.class)
public class MyServletContainerInitializer implements ServletContainerInitializer {
    @Override
    public void onStartup(Set<Class<?>> classes, ServletContext ctx) throws ServletException {
        for (Class<?> cls : classes) {
            if (cls.isAssignableFrom(Fruit.class)) {
                // Handle the class as a fruit
            }
        }
    }
}

In this example, the @HandlesTypes annotation is used to discover all classes that implement the Fruit interface. The onStartup method of the ServletContainerInitializer is then called with a set of classes that match the specified criteria. The code then loops through the set of classes and handles each one that implements the Fruit interface.

3. Discovering all classes with a particular annotation:

@HandlesTypes(Fruit.class)
public class MyServletContainerInitializer implements ServletContainerInitializer {
    @Override
    public void onStartup(Set<Class<?>> classes, ServletContext ctx) throws ServletException {
        for (Class<?> cls : classes) {
            if (cls.isAnnotationPresent(Fruit.class)) {
                // Handle the class as a fruit
            }
        }
    }
}

In this example, the @HandlesTypes annotation is used to discover all classes that are annotated with the Fruit annotation. The onStartup method of the ServletContainerInitializer is then called with a set of classes that match the specified criteria. The code then loops through the set of classes and handles each one that has the Fruit annotation.

Overall, the @HandlesTypes annotation provides a powerful way to discover and handle different types of classes in a Java web application. By specifying the types that a servlet container should discover at startup, you can easily integrate new classes into your application and handle them as needed.