A GetCategoriesRequest object gets created with an existing non-null jobId.

GetCategoriesRequest request = new GetCategoriesRequest(jobId); 

The following arguments are optional:

request.setCategoryId(1L); 

request.setPageParams(new PageParams(100, 200)); 

When executing a GetCategoriesRequest in the following manner, the client waits for the GetCategoriesResponse to be returned before continuing with code execution:

GetCategoriesResponse response = client.machineLearning().getCategories(request, RequestOptions.DEFAULT);

Executing a GetCategoriesRequest can also be done in an asynchronous fashion so that the client can return directly. Users need to specify how the response or potential failures will be handled by passing the request and a listener to the asynchronous get-categories method:

client.machineLearning().getCategoriesAsync(request, RequestOptions.DEFAULT, listener); 

The asynchronous method does not block and returns immediately. Once it is completed the ActionListener is called back using the onResponse method if the execution successfully completed or using the onFailure method if it failed.

A typical listener for get-categories looks like:

ActionListener<GetCategoriesResponse> listener =
        new ActionListener<GetCategoriesResponse>() {
            @Override
            public void onResponse(GetCategoriesResponse getcategoriesResponse) {
                
            }

            @Override
            public void onFailure(Exception e) {
                
            }
        };

The returned GetCategoriesResponse contains the requested categories:

long count = response.count(); 
List<CategoryDefinition> categories = response.categories();