Caused by: com.github.scribejava.core.exceptions.OAuthException: Response body is incorrect. Can't extract token and secret from this: 'oauth_problem=signature_invalid'
    at com.github.scribejava.core.extractors.AbstractOAuth1TokenExtractor.extract(AbstractOAuth1TokenExtractor.java:42)
    at com.github.scribejava.core.extractors.AbstractOAuth1TokenExtractor.extract(AbstractOAuth1TokenExtractor.java:32)
    at com.github.scribejava.core.extractors.AbstractOAuth1TokenExtractor.extract(AbstractOAuth1TokenExtractor.java:19)
    at com.github.scribejava.core.oauth.OAuth10aService.getRequestToken(OAuth10aService.java:51)

OAuth10aService service = new ServiceBuilder().apiKey(consumerKey).apiSecret(consumerSecret)
        .signatureType(SignatureType.QueryString)
        .build(new CustomApi(oauthUrl, username, password));
final OAuth1RequestToken requestToken = service.getRequestToken();
String authUrl = service.getAuthorizationUrl(requestToken);
final OAuth1AccessToken accessToken = service.getAccessToken(requestToken, authUrl);

final OAuthRequest request = new OAuthRequest(Verb.GET, apiUrl + url, service.getConfig());
service.signRequest(accessToken, request); // the access token from step 4
final Response response = request.send();
System.out.println(response.getBody());

public class CustomApi extends DefaultApi10a {

    private static final String REQUEST_TOKEN_URL = "/oauth/initiate?oauth_callback=oob";
    private static final String AUTHORIZE_URL = "/oauth/authorize/customerVerifier/?oauth_token=%s&username=%s&password=%s";
    private static final String ACCESS_TOKEN_URL = "/oauth/token";

    public CustomApi(String baseUrl, String username, String password) {
        this.baseUrl = baseUrl;
        this.username = username;
        this.password = password;
    }

    private String baseUrl;
    private String username;
    private String password;

    @Override
    public String getRequestTokenEndpoint() {
        return baseUrl + REQUEST_TOKEN_URL;
    }

    @Override
    public String getAuthorizationUrl(OAuth1RequestToken requestToken) {
        return String.format(baseUrl + AUTHORIZE_URL, requestToken.getToken(), username, password);
    }

    @Override
    public String getAccessTokenEndpoint() {
        return baseUrl + ACCESS_TOKEN_URL;
    }

}