es documentation 2 getapi

package sss.first;

import java.io.IOException;

import java.util.Map;

import org.elasticsearch.ElasticsearchException;

import org.elasticsearch.action.ActionListener;

import org.elasticsearch.action.get.GetRequest;

import org.elasticsearch.action.get.GetResponse;

import org.elasticsearch.client.RestHighLevelClient;

import org.elasticsearch.common.Strings;

import org.elasticsearch.index.VersionType;

import org.elasticsearch.rest.RestStatus;

import org.elasticsearch.search.fetch.subphase.FetchSourceContext;

public class GetApi {

//get api

// get request

public static GetRequest getRequest() {

GetRequest getRequest = new GetRequest(

        "posts", 

        "doc",  

        "1");   

return getRequest;

}

// optional parameters

public static void optional(RestHighLevelClient client,GetRequest request) throws IOException {

// Disable source retrieval, enabled by default

request.fetchSourceContext(new FetchSourceContext(false)); 

// Configure source inclusion for specific fields

String[] includes = new String[]{"message", "*Date"};

String[] excludes = Strings.EMPTY_ARRAY;

FetchSourceContext fetchSourceContext = new FetchSourceContext(true, includes, excludes);

request.fetchSourceContext(fetchSourceContext);

// Configure source exclusion for specific fields

String[] includes1 = Strings.EMPTY_ARRAY;

String[] excludes1 = new String[]{"message"};

FetchSourceContext fetchSourceContext1 = new FetchSourceContext(true, includes1, excludes1);

request.fetchSourceContext(fetchSourceContext1);

// Configure the retrieval of specific storage fields (requires fields to be stored separately in the map)

// Retrieve the fields stored by the message (requires the fields to be stored separately in the map)

request.storedFields("message"); 

GetResponse getResponse = client.get(request);

String message = (String) getResponse.getField("message").getValue();

// route value

request.routing("routing");

// value of parent

request.parent("parent");

// preference value

request.preference("preference");

// Set the real-time flag to false (true default)

request.realtime(false);

// perform a refresh before retrieving the document (false by default)

request.refresh(true); 

// version number

request.version(2);

// version type

request.versionType(VersionType.EXTERNAL);

}

// execute synchronously

public static GetResponse synchronous(RestHighLevelClient client,GetRequest getRequest) throws IOException {

GetResponse getResponse = client.get(getRequest);

return getResponse;

}

public static GetResponse asynchronous(RestHighLevelClient client,GetRequest getRequest) throws IOException {

client.getAsync(getRequest, new ActionListener<GetResponse>() {

@Override

public void onResponse(GetResponse response) {

// Called when execution completes successfully. The reply is provided as a parameter.

}

@Override

public void onFailure(Exception e) {

// Called on failure. The exception thrown is provided as a parameter.

}

});

return null;

}

// get response

public static void getResponse(GetResponse getResponse) {

String index = getResponse.getIndex();

String type = getResponse.getType();

String id = getResponse.getId();

if (getResponse.isExists()) {

    long version = getResponse.getVersion();

    

    // Retrieve the document String as a file

    String sourceAsString = getResponse.getSourceAsString(); 

    

    //Retrieve document as file Map<String, Object>

    Map<String, Object> sourceAsMap = getResponse.getSourceAsMap(); 

  

    //Retrieve document byte[] as file

    byte[] sourceAsBytes = getResponse.getSourceAsBytes();          

} else {

    //Handle the case where the document is not found. Note that while the returned response has a 404 status code,

// but returns a valid value GetResponse instead of throwing an exception.

// Such responses do not contain any source files and their isExists method returns false.

}

}

// When a fetch request is performed for a non-existent index, the response has a 404 status code,

//ElasticsearchException is thrown and needs to be handled as follows:

public static void tryException(RestHighLevelClient client,GetRequest request) throws IOException {

request = new GetRequest("does_not_exist", "doc", "1");

try {

    GetResponse getResponse = client.get(request);

} catch (ElasticsearchException e) {

    if (e.status() == RestStatus.NOT_FOUND) {

        //handle the exception thrown because the index does not exist

   

    }

}

}

// If a specific document version is requested, and the existing document has a different version number, a version conflict is raised:

public static void tryException2(RestHighLevelClient client,GetRequest request) throws IOException {

try {

    request = new GetRequest("posts", "doc", "1").version(2);

    GetResponse getResponse = client.get(request);

} catch (ElasticsearchException exception) {

    if (exception.status() == RestStatus.CONFLICT) {

        //The exception raised indicates that a version conflict error was returned

    }

}

}

}