Index API
editIndex API
editThe index API allows one to index a typed JSON document into a specific index and make it searchable.
Generate JSON document
editThere are several different ways of generating a JSON document:
-
Manually (aka do it yourself) using native
byte[]
or as aString
-
Using a
Map
that will be automatically converted to its JSON equivalent - Using a third party library to serialize your beans such as Jackson
- Using built-in helpers XContentFactory.jsonBuilder()
Internally, each type is converted to byte[]
(so a String is converted
to a byte[]
). Therefore, if the object is in this form already, then
use it. The jsonBuilder
is highly optimized JSON generator that
directly constructs a byte[]
.
Do It Yourself
editNothing really difficult here but note that you will have to encode dates according to the Date Format.
String json = "{" + "\"user\":\"kimchy\"," + "\"postDate\":\"2013-01-30\"," + "\"message\":\"trying out Elasticsearch\"" + "}";
Using Map
editMap is a key:values pair collection. It represents a JSON structure:
Map<String, Object> json = new HashMap<String, Object>(); json.put("user","kimchy"); json.put("postDate",new Date()); json.put("message","trying out Elasticsearch");
Serialize your beans
editYou can use Jackson to serialize
your beans to JSON. Please add Jackson Databind
to your project. Then you can use ObjectMapper
to serialize your beans:
import com.fasterxml.jackson.databind.*; // instance a json mapper ObjectMapper mapper = new ObjectMapper(); // create once, reuse // generate json byte[] json = mapper.writeValueAsBytes(yourbeaninstance);
Use Elasticsearch helpers
editElasticsearch provides built-in helpers to generate JSON content.
import static org.elasticsearch.common.xcontent.XContentFactory.*; XContentBuilder builder = jsonBuilder() .startObject() .field("user", "kimchy") .field("postDate", new Date()) .field("message", "trying out Elasticsearch") .endObject()
Note that you can also add arrays with startArray(String)
and
endArray()
methods. By the way, the field
method
accepts many object types. You can directly pass numbers, dates and even
other XContentBuilder objects.
If you need to see the generated JSON content, you can use the
Strings.toString()
method.
import org.elasticsearch.common.Strings; String json = Strings.toString(builder);
Index document
editThe following example indexes a JSON document into an index called
twitter, under a type called _doc
, with id valued 1:
import static org.elasticsearch.common.xcontent.XContentFactory.*; IndexResponse response = client.prepareIndex("twitter", "_doc", "1") .setSource(jsonBuilder() .startObject() .field("user", "kimchy") .field("postDate", new Date()) .field("message", "trying out Elasticsearch") .endObject() ) .get();
Note that you can also index your documents as JSON String and that you don’t have to give an ID:
String json = "{" + "\"user\":\"kimchy\"," + "\"postDate\":\"2013-01-30\"," + "\"message\":\"trying out Elasticsearch\"" + "}"; IndexResponse response = client.prepareIndex("twitter", "_doc") .setSource(json, XContentType.JSON) .get();
IndexResponse
object will give you a report:
// Index name String _index = response.getIndex(); // Type name String _type = response.getType(); // Document ID (generated or not) String _id = response.getId(); // Version (if it's the first time you index this document, you will get: 1) long _version = response.getVersion(); // status has stored current instance statement. RestStatus status = response.status();
For more information on the index operation, check out the REST index docs.