Get Composable Index Templates API

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The Get Index Templates API allows to retrieve information about one or more index templates.

Get Composable Index Templates Request

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A GetIndexTemplateV2Request specifies one, or a wildcard expression of index template names to get. To return all index templates, omit the name altogether or use a value of *.

GetComposableIndexTemplateRequest request = new GetComposableIndexTemplateRequest("my-template"); 
request = new GetComposableIndexTemplateRequest("my-*"); 

A single index template name

An index template name using wildcard

request.setMasterNodeTimeout(TimeValue.timeValueMinutes(1)); 
request.setMasterNodeTimeout("1m"); 

Timeout to connect to the master node as a TimeValue

Timeout to connect to the master node as a String

Synchronous execution

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When executing a GetIndexTemplateV2Request in the following manner, the client waits for the GetIndexTemplatesV2Response to be returned before continuing with code execution:

GetComposableIndexTemplatesResponse getTemplatesResponse = client.indices().getIndexTemplate(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

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Executing a GetIndexTemplateV2Request 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-index-templates-v2 method:

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

The GetIndexTemplateV2Request 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-index-templates-v2 looks like:

ActionListener<GetComposableIndexTemplatesResponse> listener =
    new ActionListener<GetComposableIndexTemplatesResponse>() {
        @Override
        public void onResponse(GetComposableIndexTemplatesResponse response) {
            
        }

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

Called when the execution is successfully completed.

Called when the whole GetIndexTemplateV2Request fails.

Get Templates Response

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The returned GetIndexTemplatesV2Response consists a map of index template names and their corresponding configurations.

Map<String, ComposableIndexTemplate> templates = getTemplatesResponse.getIndexTemplates(); 

A map of matching index templates names and the corresponding configurations