Gemasoft's questions

I really don't understand what the purpose of each one is since they perform very similar tasks.

Could someone explain to me what is the difference between an Interceptor and a Filter in Spring?

What fundamental difference is there in initializing the Spring configuration classes in getRootConfigClasses and getServletConfigClasses in the WebInitializer class ?

I have tried changing the initialization of my configuration classes in both methods without different results, the theory says that they are different contexts but both ways work the same.

I would like to know what the correct way is or if it represents any impact on my project to have it in one way or another.

    @Configuration
public class WebInitializer extends AbstractAnnotationConfigDispatcherServletInitializer{

    @Override
    protected Class<?>[] getRootConfigClasses() {
        return new Class<?>[]{SecurityConfig.class};
    }

    @Override
    protected Class<?>[] getServletConfigClasses() {
        return new Class<?>[]{WebConfig.class, SwaggerConfig.class};
    }

    @Override
    protected Filter[] getServletFilters() {
         return new Filter[] {new DelegatingFilterProxy("springSecurityFilterChain")};
    }

    @Override
    protected String[] getServletMappings() {
        return new String[]{"/"};
    }

}

It works the same way, for example:

 @Configuration
    public class WebInitializer extends AbstractAnnotationConfigDispatcherServletInitializer{

        @Override
        protected Class<?>[] getRootConfigClasses() {
            return new Class<?>[]{WebConfig.class, SecurityConfig.class,SwaggerConfig.class};
        }

        @Override
        protected Class<?>[] getServletConfigClasses() {
            return new Class<?>[]{};
        }

        @Override
        protected Filter[] getServletFilters() {
             return new Filter[] {new DelegatingFilterProxy("springSecurityFilterChain")};
        }

        @Override
        protected String[] getServletMappings() {
            return new String[]{"/"};
        }

    }

I understand that the second option will cause an exception when it is actually null, but is there another reason?

I would like to know what are the fundamental differences between both technologies.

Can someone explain to me what is the difference between:

char* name = "Gerardo";

either

char name[] = "Gerardo";

I would like to know the differences in terms of memory or performance.

Is there a way to install Apache Maven with apt-get?

For now I have to go to the Apache Maven site and download the files and then from my editor (Eclipse, IntelliJ) I reference that folder to leave it configured.

I would like to know if there is a way to configure it using apt-getso that I do not have to do all of the above.

Is there any way I can get the hostname (client) using Javascript?

I am using Java 7 to develop a conference scheduling application.

I have seen that there are several data types to handle dates.

Example:

private Date creationDate;

private DateTime creationDate;

private Calendar creationDate;

My question is: What is the difference between type Calendar, Dateand DateTime?

I see that several can be used but I don't understand their differences or when I should use one or the other, for example:

    text/javascript
    text/x-javascript
    text/x-json
    application/json
    application/x-javascript

I wrote something I didn't want in the commit comment.

git commit -m "comentario indeseado"

git push

How can I change or update the message?

Eye, I already did push and I want to remove the message in the repository too.

It's possible?

I started using Objectifyit as a library to work more comfortably with it Google Datastore, Google App Enginebut I have a doubt and I don't know the difference between using Refand Keyin the definition of properties of my entity.

For example:

@Entity
public class Car {

    @Id
    Long id;

    Key<User> driver;
}

either

@Entity
public class Car {

    @Id
    Long id;

    Ref<User> driver;
}

Apparently both generate a relationship with the User entity but I don't understand what the difference is between using one or the other since when making queries or inserting data they behave exactly the same.

Does anyone know what the fundamental difference is?

Some files were uploaded to my repository by mistake and I would like to know if there is any method to delete them completely since if I delete them and commit them, the history that they were once there is still left.

Recently I have noticed that there are several sites that ask for permission to use cookies and before they did not, does anyone know why? Is it something that I have to apply on my websites?

I have an online store with wordpress and woocommerce and I'm from Mexico.

I would like to know what are prototypes in JavaScript and how can I use them or if there is any kind of benefit.

I have an application in spring mvc and I have read a little about oauth to authenticate my users but the truth is that it has not been very clear to me, could you explain to me what oauth is about?

Suppose I have the following JPA repository:

public interface IGreetingRepository extends JpaRepository<Greeting, Long> {
}

And according to the documentation you would have to generate a service interface as follows:

public interface IGreetingService {

    Greeting getGreetingById(Long id);

    List<Greeting> getAllGreetings();

    Greeting saveGreeting(Greeting greeting);

    void deleteGreeting(Long id);

}

And after the implementation:

@Service
@Qualifier("greetingService")
public class GreetingServiceImpl implements IGreetingService {

    @Autowired
    @Qualifier("greetingRepository")
    IGreetingRepository greetingRepository;

    @Override
    public Greeting getGreetingById(Long id) {
        return greetingRepository.findOne(id);
    }

    @Override
    public List<Greeting> getAllGreetings() {
        return greetingRepository.findAll();
    }

    @Override
    public Greeting saveGreeting(Greeting greeting) {
        return greetingRepository.save(greeting);
    }

    @Override
    public void deleteGreeting(Long id) {
        greetingRepository.delete(id);
    }
}

And to make use of my service in my controllers I would inject it like this:

@Autowired
@Qualifier("greetingService")
GreetingService greetingService;

What I don't understand is, what is the advantage of doing it like this instead of directly injecting the JPA repository interface and saving me the 2 classes?:

@Autowired
@Qualifier("greetingRepository")
IGreetingRepository greetingRepository;

I need to get the digital root of a positive number using Python, so far my algorithms don't work.

In theory, the digits of each number should be added until there is only 1 digit left in the number.

For example:

127 = 1+2+7 = 10
1+0 = 1

Therefore the digital root of 127 would be 1.

This was my last algorithm:

def getDigitalRoot(num):
    return num if num==9 else num%9

But it doesn't work well since if I put for example 99 it returns 0 and it would have to be 9.

I have been researching about delegates in C# but the truth is not that clear to me yet.

Can someone explain to me what it is about?

If I have a string variable with the following value:

var myString = "{'nombre':'juan'}";

How can I convert a string to a JSON object in JavaScript?

For example, when entering the Domino's page, it asks for permission to obtain the location and I was surprised because it is very precise.