Get Mappings API

edit

Get Mappings Request

edit

A GetMappingsRequest can have an optional list of indices:

GetMappingsRequest request = new GetMappingsRequest(); 
request.indices("twitter"); 

An empty request that will return all indices

Setting the indices to fetch mapping for

Optional arguments

edit

The following arguments can also optionally be provided:

request.setMasterTimeout(TimeValue.timeValueMinutes(1)); 

Timeout to connect to the master node as a TimeValue

request.indicesOptions(IndicesOptions.lenientExpandOpen()); 

Options for expanding indices names

Synchronous execution

edit

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

GetMappingsResponse getMappingResponse = client.indices().getMapping(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 execution

edit

Executing a GetMappingsRequest 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-mappings method:

client.indices().getMappingAsync(request, RequestOptions.DEFAULT, listener); 

The GetMappingsRequest 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-mappings looks like:

ActionListener<GetMappingsResponse> listener =
    new ActionListener<GetMappingsResponse>() {
        @Override
        public void onResponse(GetMappingsResponse putMappingResponse) {
            
        }

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

Called when the execution is successfully completed.

Called when the whole GetMappingsRequest fails.

Get Mappings Response

edit

The returned GetMappingsResponse allows to retrieve information about the executed operation as follows:

Map<String, MappingMetadata> allMappings = getMappingResponse.mappings(); 
MappingMetadata indexMapping = allMappings.get("twitter"); 
Map<String, Object> mapping = indexMapping.sourceAsMap(); 

Returning all indices' mappings

Retrieving the mappings for a particular index

Getting the mappings as a Java Map