Get categories APIedit

Retrieves one or more category results. It accepts a GetCategoriesRequest object and responds with a GetCategoriesResponse object.

Get categories requestedit

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

GetCategoriesRequest request = new GetCategoriesRequest(jobId); 

Constructing a new request referencing an existing jobId.

Optional argumentsedit

The following arguments are optional:


The ID of the category to get. Otherwise, it will return all categories.

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

The page parameters from and size. from specifies the number of categories to skip. size specifies the maximum number of categories to get. Defaults to 0 and 100 respectively.

Synchronous executionedit

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);

Synchronous calls may throw an IOException in case of either failing to parse the REST response in the high-level REST client, the request times out or similar cases where there is no response coming back from the server.

In cases where the server returns a 4xx or 5xx error code, the high-level client tries to parse the response body error details instead and then throws a generic ElasticsearchException and adds the original ResponseException as a suppressed exception to it.

Asynchronous executionedit

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 GetCategoriesRequest to execute and the ActionListener to use when the execution completes

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. Failure scenarios and expected exceptions are the same as in the synchronous execution case.

A typical listener for get-categories looks like:

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

            public void onFailure(Exception e) {

Called when the execution is successfully completed.

Called when the whole GetCategoriesRequest fails.

Get categories responseedit

The returned GetCategoriesResponse contains the requested categories:

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

The count of categories that were matched.

The categories retrieved.