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javaapacheproxyodataolingo

How to use Apache Olingo behind a proxy

I can successfully reach following OData-service using different browsers and also using Postman even so I am behind a proxy: String SERVICE_ROOT = http://services.odata.org/V4/TripPinService/

However, using Apache Olingo in Java I am not able to access this service.

JVM parameters like -Dhttp.proxySet=true -Dhttp.proxyHost=http-proxy.example.com -Dhttp.proxyPort=8080 allow me to perform basic URL functions, like retrieving HTTP status codes (google returns 200). Nevertheless, access of the OData-Service using an ODataClient is not possible (code below). No errors are thrown. 

ODataClient client = ODataClientFactory.getClient();
ODataServiceDocumentRequest request = client.getRetrieveRequestFactory().getServiceDocumentRequest(SERVICE_ROOT);
ODataRetrieveResponse<ClientServiceDocument> response = request.execute();

I tried using the proxy capabilities within Olingo, however without any success:

client.getConfiguration().setHttpClientFactory(new ProxyWrappingHttpClientFactory(URI.create("http://http-proxy.example.com:8080")));

What am I doing wrong, what options do I have left?

Thank you very much.

Solution

  • If you are behind an NTLM proxy you can try with NTLMAuthHttpClientFactory.

    NTLMAuthHttpClientFactory ntlm = new NTLMAuthHttpClientFactory(username, password, workstation, domain);
client.getConfiguration().setHttpClientFactory(ntlm);

    In case that doesn't work, you can try with cntlm. Install it, change username, password, domain and proxy in C:\Program Files (x86)\Cntlm\cntlm.ini and then invoke net start cntlm. Use this for Olingo:

    client.getConfiguration().setHttpClientFactory(new ProxyWrappingHttpClientFactory(URI.create("http://localhost:3128")));