How to use EDMX source as EDM Provider within an OData Service¶

How To Guide for the using an EDM Parser¶

The EDM Parser is designed to parse the metadata document. To make the parser accessible from the API, we have to implement the method readMetadata from interface org.apache.olingo.odata2.api.ep.EntityProviderInterface:

 @Override
 public Edm readMetadata(final InputStream inputStream, final boolean validate) throws EntityProviderException {
   EdmProvider provider = new EdmxProvider().parse(inputStream, validate);
   return new EdmImplProv(provider);
  }

The signature contains the InputStream that represents a data stream read from a file and flag validate. If validate is set to true, the structure of the metadata will be checked according to the CSDL after parsing. For example: it will be validated that each EntityType defines a key element or derives from a BaseType that for its part defines a key.

To start the parsing we have to follow the next steps:

create an object of the class EdmxProvider. This class derives from EdmProvider and provides implementations for all of its abstract methods
invoke the method parse(InputStream, boolean) of this object

Returned is an EDM object that contains the complete information from parsed metadata.

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