how to consume ODATA service in Java client

[Former Member]

hi Team,

I created an ODATA service and in which I exposed a calculation view which gives the City details if we input the Customer Id into it.

the following is the URL which got estabilshed:

http://xx.xxx.xxx.xx:80xx/PKG_TEST/xsproject1/customer_det.xsodata/customer_det?$format=json&$select... eq 1)

My questions are:

1)how can we call this URL from a JAVA client?

2)for testing from a JAVA client, can I use the JAVA perspective of HANA Studio?

3)if point(2) is yes, then how can create a JAVA application and what are the necessary JAR files needed to run this application?

4)if point(2) is yes, how can I ensure that JAVA perspective is pointing to JRE which is installed on my system?

please provide inputs on the above points to proceed further in the development.

Regards,

Vishnu

[pfefferf]

Hello Vishnu,

one option would be to use Apache Olingo as OData Client Library. The tutorial https://olingo.apache.org/doc/odata2/tutorials/OlingoV2BasicClientSample.html#sampleservice which describes the creation of a OData client for a sample service should give you all necessary information regarding packages, development steps.

The Java perspective within the HANA Studio can be used. Regarding the JRE, check your settings under Window -> Preferences -> Java -> Installed JREs.

Best Regards,

Florian

[Former Member]

hi Forian,

thanks for your mail.

I tried to implement the logic provided in the link of Olingo, but getting a huge amounts of errors may be due the reason that there were not enough/correct JAR files.

well I tried with another logic as under:

public class RSClient {

public static void main(String[] args) {

  Client c  = Client.create(new DefaultClientConfig());

  WebResource res = c.resource(buildURI()); 

  String result = res.accept(MediaType.TEXT_PLAIN);

  System.out.println("City"+result);

}

private static URI buildURI(){

     return UriBuilder.fromUri("http://10.xxx.xx.xx:80xx/PKG_TEST/xsproject1/customer_det.xsodata/customer_det?$format=json&$select=...)").build(null);

}

}

I imported all the necessary JAR files relating to JERSEY -> which is need for calling Webservice of ODATA from a Java environment -> Java Perspective in HANA studio, but getting the following error as:

"the method accept(MediaType[]) in the type WebResource is not applicable for the arguments(String)" but for the MediaType .TEXT_HTML/TEXT_PLAIN/TEXT_XML have a return type as STRING...

even though the result is defined as STRING and MediaType.TEXT_PLAIN is also a STRING, why this error is not getting removed?

please provide inputs on the above point to proceed further.

Regards,

Vishnu