How to handle HTTP OPTIONS requests in Spring Boot?

Option 1: Spring Boot properties (Spring Boot 1.3.0+ only)

Starting with Spring Boot 1.3.0 this behavior can be configured using following property:

spring.mvc.dispatch-options-request=true

Option 2: Custom DispatcherServlet

DispatcherServlet in Spring Boot is defined by DispatcherServletAutoConfiguration. You can create your own DispatcherServlet bean somewhere in your configuration classes, which will be used instead of the one in auto configuration:

@Bean(name = DispatcherServletAutoConfiguration.DEFAULT_DISPATCHER_SERVLET_BEAN_NAME)
public DispatcherServlet dispatcherServlet() {
    DispatcherServlet dispatcherServlet = new DispatcherServlet();
    dispatcherServlet.setDispatchOptionsRequest(true);
    return dispatcherServlet;
}

But be aware that defining your DispatcherServlet bean will disable the auto configuration, so you should manually define other beans declared in the autoconfiguration class, namely the ServletRegistrationBean for DispatcherServlet.

Option 3: BeanPostProcessor

You can create BeanPostProcessor implementation which will set the dispatchOptionsRequest attribute to true before the bean is initialized. Yoy can put this somewhere in your configuration classes:

@Bean
public DispatcherServletBeanPostProcessor dispatcherServletBeanPostProcessor() {
    return new DispatcherServletBeanPostProcessor();
}

public static class DispatcherServletBeanPostProcessor implements BeanPostProcessor {
    @Override
    public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {
        if (bean instanceof DispatcherServlet) {
            ((DispatcherServlet) bean).setDispatchOptionsRequest(true);
        }
        return bean;
    }

    @Override
    public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {
        return bean;
    }
}

Option 4: SpringBootServletInitializer

If you had SpringBootServletInitializer in your application you could do something like this to enable OPTIONS dispatch:

public class ServletInitializer extends SpringBootServletInitializer {
    @Override
    protected SpringApplicationBuilder configure(SpringApplicationBuilder application) {
        return application.sources(Application.class);
    }

    @Override
    public void onStartup(ServletContext servletContext) throws ServletException {
        super.onStartup(servletContext);
        servletContext.getServletRegistration(DispatcherServletAutoConfiguration.DEFAULT_DISPATCHER_SERVLET_BEAN_NAME)
                .setInitParameter("dispatchOptionsRequest", "true");
    }
}

That would however only work if you deployed your app as a WAR into Servlet container, as the SpringBootServletInitializer code is not executed when running your Spring Boot app using main method.