public URI createRedirectUri() {
Map<String, String> parameters = Maps.newHashMap();
parameters.put("response_type", "code");
parameters.put("client_id", clientId);
parameters.put("redirect_uri", uriBuilder.forPath(OAuthCallbackServlet.PATH).toString());
parameters.put("scope", Joiner.on(" ").join(SCOPE));
parameters.put("access_type", "online");
parameters.put("state", uriBuilder.forPath("/").toString());
try {
return new URI(
"https",
"accounts.google.com",
"/o/oauth2/auth",
buildKeyValueString(parameters, false),
null);
} catch (URISyntaxException e) {
throw new IllegalArgumentException(e);
}
}
public UserId determineUserId(String code) throws IOException {
Map<String, String> parameters = Maps.newHashMap();
parameters.put("code", code);
parameters.put("client_id", clientId);
parameters.put("client_secret", clientSecret);
parameters.put("redirect_uri", uriBuilder.forPath(OAuthCallbackServlet.PATH).toString());
parameters.put("grant_type", "authorization_code");
HTTPRequest fetchRequest =
new HTTPRequest(new URL("https://accounts.google.com/o/oauth2/token"), HTTPMethod.POST);
fetchRequest.setPayload(buildKeyValueString(parameters, true).getBytes());
HTTPResponse response = urlFetchService.fetch(fetchRequest);
JsonObject object = jsonParser.parse(new String(response.getContent())).getAsJsonObject();
String access_token = object.get("access_token").getAsString();
HTTPRequest secondRequest =
new HTTPRequest(new URL("https://www.googleapis.com/oauth2/v1/userinfo"));
secondRequest.addHeader(
new HTTPHeader("Authorization", String.format("Bearer %s", access_token)));
response = urlFetchService.fetch(secondRequest);
object = jsonParser.parse(new String(response.getContent())).getAsJsonObject();
return UserId.fromString(object.get("id").getAsString());
}
