How to use Java High Level Rest Client with Spring Boot to talk to Elasticsearch 6.x

Original Document
How to use Java High Level Rest Client with Spring Boot to talk to AWS Elasticsearch

Original Source
spring-boot-java-highlevel-rest-client-elasticsearch

I rewrites source and test about ES 6.5.
https://github.com/maxmin93/spring-boot-java-highlevel-rest-client-elasticsearch

create new document to index ‘profile’ (type ‘person’)

// POST http://localhost:8080/api/v1/profiles
{
  "firstName": "Bob",
  "lastName": "Labla",
  "technologies": [
    { "name": "Angular 6", "yearsOfExperience": "1 year" }
  ],
  "emails": [ "bob@email.com" ]
}

// PUT http://localhost:8080/api/v1/profiles
{
  "id": "55fb8543-6bce-4478-bc7e-5df52e544dbe",
  "firstName": "Bob",
  "lastName": "Labla (A)",
  "technologies": [
    { "name": "Angular 6", "yearsOfExperience": "1 year" },
    { "name": "Javascript", "yearsOfExperience": "3 year" },
    { "name": "Java 8", "yearsOfExperience": "2 year" }
  ],
  "emails": [ "bob_new@email.com" ]
}

list all documents of index ‘profile’ (type ‘person’)

And I added some lines about checking index existence, creating index and list all indices.

    @PostConstruct
    public void checkIndexExists() throws IOException {
        GetIndexRequest request = new GetIndexRequest();
        request.indices(INDEX);

        boolean exists = false;
        try {
            exists = client.indices().exists(request, RequestOptions.DEFAULT);
        } catch (IOException e){
            log.info(String.format("es-index[%s] does not exists on connection.", INDEX));
        }

        if( !exists ){
            boolean isCreated = false;
            try {
                isCreated = createEsIndex(INDEX, TYPE);
            } catch (IOException e){
                log.info(String.format("es-index[%s]-type[%s] cannot be created.", INDEX, TYPE));
            }
            if( isCreated )
                System.out.println(String.format("es-index[%s]-type[%s] is created.", INDEX, TYPE));
        }

        System.out.println("# es-indices :");
        fetchIndices().forEach(r -> System.out.println("  - "+r.toString()));
    }

    // https://www.elastic.co/guide/en/elasticsearch/client/java-rest/master/java-rest-high-create-index.html
    private boolean createEsIndex(String index, String type) throws IOException {

        CreateIndexRequest request = new CreateIndexRequest(INDEX);
        request.settings(Settings.builder()
                .put("index.number_of_shards", 1)
                .put("index.number_of_replicas", 0)
        );
        // json data can be replaced "file.json" in resouces path
        request.mapping(TYPE,
                "{\n" +
                        "  \""+TYPE+"\": {\n" +
                        "    \"properties\": {\n" +
                        "      \"firstName\": {\"type\": \"text\"},\n" +
                        "      \"lastName\": {\"type\": \"text\"},\n" +
                        "      \"technologies\": {\"type\": \"nested\"}\n" +
                        "    }\n" +
                        "  }\n" +
                        "}",
                XContentType.JSON);

        final CreateIndexResponse response = client.indices().create(request, RequestOptions.DEFAULT);
        final boolean acknowledged = response.isAcknowledged();
        return acknowledged;
    }

    // https://stackoverflow.com/a/52335626
    public List<String> fetchIndices() throws IOException {
        GetIndexRequest request = new GetIndexRequest().indices("*");
        GetIndexResponse response = client.indices().get(request, RequestOptions.DEFAULT);
        String[] indices = response.getIndices();
        return Arrays.asList(indices);
    }

You can replace mapping setting to json file.