Olingo - Create strongly typed POJOs for client library of OData service

Question

I\'m using Apache Olingo as an OData client for a Java SDK that I will provide for a RESTful OData API. In the SDK I want to be able to have strongly typed classes to repres

Answer 1

It is not really advertised, but there is nowadays a POJO generator in Olingo, in the source tree at ext / pojogen-maven-plugin. Unfortunately for using the POJOs another layer with a different programming model is added, which holds entities cached in memory and syncs with OData service on a flush operation. I would be really interested in adapting it to a more conventional request/response model based on Olingos Request Factories.

However, you could try it out. In your pom include pojogen-maven-plugin and odata-client-proxy. The POJO generation can be triggered in the pom with

    
        org.codehaus.mojo
        build-helper-maven-plugin
        1.8
        
            
                process-sources
                
                    add-source
                
                
                    
                        ${project.build.directory}/generated-sources
                    
                
            
        
    

    
        org.apache.olingo
        pojogen-maven-plugin
        4.2.0-SNAPSHOT
        
            ${project.build.directory}/generated-sources
            ${basedir}/src/main/resources/metadata.xml
            odata.test.pojo
        
        
            
                v4pojoGen
                generate-sources
                
                    v4pojoGen
                
            
        
    

For the experiment I stored the EDM Metadataof the Olingo Car example service at src/main/resources/metadata.xml. Somehow the plugin wants to create an inbetween ojc-plugin folder and I just moved the generated Java code at the proper place manually.

At that point you have a Service.java and Java interfaces for each entity or complex type in the EDM model.

You can make use of it to read some entities like this

Service service = odata.test.pojo.Service.getV4("http://localhost:9080/odata-server-sample/cars.svc");
Container container = service.getEntityContainer(Container.class);
for (Manufacturer m : container.getManufacturers()) {
    System.out.println(m.getName());
}