在播放1.2.5中使用@before注释？

Question

I want the session to be checked before sending a user to the login - whereby each URL request results in checking whether this is from a valid session - if not, send them to the login page, else process as normal. If the user already has an active session, we will not show them the login page but take them to a pre-defined main page.

I searched on google related to it, and come to know that it will done by using @Before annotaion in controller but dont know about @Before working and how to use? I'm using play 1.2.5.

Answer 1

You can use the @Before this way:

@Before
static void addUser() {
    User user = connected();
    if(user != null) {
        renderArgs.put("user", user);
    }
}

static User connected() {
    if(renderArgs.get("user") != null) {
        return renderArgs.get("user", User.class);
    }
    // Find your user from session
    String username = session.get("user");
    if(username != null) {
        return User.find("byUsername", username).first();
    } 
    return null;
}

// ~~render your login if the user is not finded in session

public static void index() {
    if(connected() != null) {
         render();
    }
    login();
}

You can find this sample code in YOUR_PLAY_DIR/samples-and-tests/booking.

As @emt14 said, you can do this with the Play secure module more easily. Check out the forum apps samples in YOUR_PLAY_DIR/samples-and-tests/forum.

Answer 2

The Play secure module does exactly that out of the box. It is used by most applications and integrates with different plugins as well. Check out the documentation here .

If you still want to implement it yourself you can use the secure code as an example.

Otherwise @Before can be used on any of your controller static methods and has access to all the scope Objects, including session.