从InputStream / String Olingo4获取Edm

Question

In Olingo 2 I could do this:

Edm metadataEdm = EntityProvider.readMetadata(metadataInputStream, false); //metadataInputStream is java.io.InputStream

From what I have read in Olingo 4, you can do this:

ODataClient client = ODataClientFactory.getClient();

            String serviceRoot = "http://services.odata.org/V4/Northwind/Northwind.svc";
            EdmMetadataRequest request
               = client.getRetrieveRequestFactory().getMetadataRequest(serviceRoot);

            ODataRetrieveResponse<Edm> response = request.execute();

But in my project I can only use HTTPClient for any network calls - which means I can't use ODataClient client .

From HttpClient I can get the InputStream . Is there a way (as shown above for Olingo 2) to get the Edm object from InputStream in Olingo 4 ?

Answer 1

Yes there is a way to do this in Olingo 4 using the ODataReader .It accepts input stream in method Edm readMetadata(InputStream input);

Your code above can be modified in the following way to achieve the same result.

ODataReader reader = ODataClientFactory.getClient().getReader();

String serviceRoot = "http://services.odata.org/V4/Northwind/Northwind.svc/$metadata";

HttpClient httpClient = new DefaultHttpClient();
HttpGet httpGet = new HttpGet(serviceRoot);

httpGet.addHeader("Accept", "application/xml"); // Looks like version 4.4.0 of OData client only supports xml format for metadata

HttpResponse response = httpClient.execute(httpGet);
Edm edm = reader.readMetadata(response.getEntity().getContent());