OAuth2 Java - 如何设置Accept标头

Question

I'm trying to implement a "sign in with Github" feature for my site with a hybrid solution - the site's javascript does the initial login/credentials, and the redirect url is for a tomcat servlet continuing the access token request.

I'm using Google API oauth2 library for Java.

My code currently looks like this:

AuthorizationCodeTokenRequest tokenRequest =
    new AuthorizationCodeTokenRequest(
            new NetHttpTransport(),
            new JacksonFactory(),
            new GenericUrl("https://github.com/login/oauth/access_token"),
            code)
            .setClientAuthentication(
                new ClientParametersAuthentication(
                    GITHUB_CLIENT_ID, GITHUB_CLIENT_SECRET));

TokenResponse tokenResponse = tokenRequest.execute();

This doesn't work, and I'm getting the following exception:

com.fasterxml.jackson.core.JsonParseException: Unrecognized token 'access_token': was expecting ('true', 'false' or 'null')

I've looked into it, and found the response from Github is not in a json format (which the JacksonFactory expects), but actually looks like this:

access_token=xxxxxxxxxxx&scope=user%3Aemail&token_type=bearer

I've found in https://developer.github.com/v3/media/#request-specific-version that I need to set the Accept http header of the request to be application/vnd.github.v3+json for it to return something in json format.

How can I do this with Google's oauth2 api?

EDIT: Based on tinker 's response, I solved with the following addition:

tokenRequest.setRequestInitializer(new HttpRequestInitializer()
{
    @Override
    public void initialize(HttpRequest request) throws IOException
    {
        request.getHeaders().setAccept("application/json");
    }
});

Answer 1

You have to create an HttpRequest and add the headers to that. Look at javadoc for setting the request headers here.

From the AuthorizationCodeTokenRequest you can get the HttpRequestInitializer using getRequestInitializer() . If this is null then you can create an initalizer and use setRequestInitializer() with the newly created object.

With the initializer you can now initialize the request that has the desired headers.

I haven't tested this so I'm not absolutely sure, but from the docs this looks like the only way to do it.