How can I check if a method is static using reflection?

Use Modifier.isStatic(method.getModifiers()).

/**
 * Returns the public static methods of a class or interface,
 *   including those declared in super classes and interfaces.
 */
public static List<Method> getStaticMethods(Class<?> clazz) {
    List<Method> methods = new ArrayList<Method>();
    for (Method method : clazz.getMethods()) {
        if (Modifier.isStatic(method.getModifiers())) {
            methods.add(method);
        }
    }
    return Collections.unmodifiableList(methods);
}

Note: This method is actually dangerous from a security standpoint. Class.getMethods “bypass[es] SecurityManager checks depending on the immediate caller’s class loader” (see section 6 of the Java secure coding guidelines).

Disclaimer: Not tested or even compiled.

Note Modifier should be used with care. Flags represented as ints are not type safe. A common mistake is to test a modifier flag on a type of reflection object that it does not apply to. It may be the case that a flag in the same position is set to denote some other information.