Q:

android basic auth okhttpclient

I am connecting to my rest api using retrofit and okHttp client. When I disable Basic authentication on Tomcat everything works flawlessly. 
When Basic Auth is enabled on Tomcat I get 404 Page not found.
Here is my authentication and error output.
    okHttpClient.setAuthenticator(new Authenticator() {
        @Override
        public Request authenticate(Proxy proxy, Response response) throws IOException {
            String credential = Credentials.basic(rest_user, rest_pw);
            return response.request().newBuilder().header("Authorization", credential).build();
        }

        @Override
        public Request authenticateProxy(Proxy proxy, Response response) throws IOException {
            return null;
        }
    });

Error log
    D/YOUR_LOG_TAG: <--- HTTP 404 https://myserver:8443/RestWS/objects/barcodes (4462ms)
    D/YOUR_LOG_TAG: Server: Apache-Coyote/1.1
    D/YOUR_LOG_TAG: Cache-Control: private
    D/YOUR_LOG_TAG: Expires: Thu, 01 Jan 1970 01:00:00 CET
    D/YOUR_LOG_TAG: Set-Cookie: JSESSIONID=*********************; Path=/; Secure; HttpOnly
    D/YOUR_LOG_TAG: Content-Type: text/html;charset=ISO-8859-1
    D/YOUR_LOG_TAG: Content-Length: 127
    D/YOUR_LOG_TAG: Date: Tue, 26 Apr 2016 09:31:22 GMT
    D/YOUR_LOG_TAG: OkHttp-Selected-Protocol: http/1.1
    D/YOUR_LOG_TAG: OkHttp-Sent-Millis: 1461663081883
    D/YOUR_LOG_TAG: OkHttp-Received-Millis: 1461663081973
    D/YOUR_LOG_TAG: <html>
            D/YOUR_LOG_TAG: <head>
            D/YOUR_LOG_TAG: <title>404-Page Not Found</title>
            D/YOUR_LOG_TAG: </head>
            D/YOUR_LOG_TAG: <body> The requested URL was not found on this server. </body>
            D/YOUR_LOG_TAG: </html>
            D/YOUR_LOG_TAG: <--- END HTTP (127-byte body)

A:

Problem solved using RequestInterceptor. 
  restAdapter = new RestAdapter.Builder()
            .setConverter(new GsonConverter(gson))
            .setRequestInterceptor(new RequestInterceptor() {
                @Override
                public void intercept(RequestFacade request) {
                    String credentials = DownloadService.rest_user + ":" + DownloadService.rest_pw;
                    String base64EncodedCredentials = Base64.encodeToString(credentials.getBytes(), Base64.NO_WRAP);
                    request.addHeader("Authorization", "Basic " + base64EncodedCredentials);
                }
            })
            .setEndpoint(DownloadService.URL)
            .setClient(new OkClient(okHttpClient))
            .build();

