Get API
editGet API
editGet Request
editA GetRequest
requires the following arguments:
Optional arguments
editThe following arguments can optionally be provided:
String[] includes = new String[]{"message", "*Date"}; String[] excludes = Strings.EMPTY_ARRAY; FetchSourceContext fetchSourceContext = new FetchSourceContext(true, includes, excludes); request.fetchSourceContext(fetchSourceContext);
String[] includes = Strings.EMPTY_ARRAY; String[] excludes = new String[]{"message"}; FetchSourceContext fetchSourceContext = new FetchSourceContext(true, includes, excludes); request.fetchSourceContext(fetchSourceContext);
request.storedFields("message"); GetResponse getResponse = client.get(request, RequestOptions.DEFAULT); String message = getResponse.getField("message").getValue();
Configure retrieval for specific stored fields (requires fields to be stored separately in the mappings) |
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Retrieve the |
Synchronous execution
editWhen executing a GetRequest
in the following manner, the client waits
for the GetResponse
to be returned before continuing with code execution:
GetResponse getResponse = client.get(getRequest, 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
editExecuting a GetRequest
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 method:
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
looks like:
Get Response
editThe returned GetResponse
allows to retrieve the requested document along with
its metadata and eventually stored fields.
String index = getResponse.getIndex(); String id = getResponse.getId(); if (getResponse.isExists()) { long version = getResponse.getVersion(); String sourceAsString = getResponse.getSourceAsString(); Map<String, Object> sourceAsMap = getResponse.getSourceAsMap(); byte[] sourceAsBytes = getResponse.getSourceAsBytes(); } else { }
Retrieve the document as a |
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Retrieve the document as a |
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Retrieve the document as a |
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Handle the scenario where the document was not found. Note that although
the returned response has |
When a get request is performed against an index that does not exist, the
response has 404
status code, an ElasticsearchException
gets thrown
which needs to be handled as follows:
GetRequest request = new GetRequest("does_not_exist", "1"); try { GetResponse getResponse = client.get(request, RequestOptions.DEFAULT); } catch (ElasticsearchException e) { if (e.status() == RestStatus.NOT_FOUND) { } }
In case a specific document version has been requested, and the existing document has a different version number, a version conflict is raised: