一文读懂 Java操作Elasticsearch( 七 ) _Elasticsearch

ElasticsearchExceptionIndexRequest request = new IndexRequest("posts").id("1").source("field", "value").setIfSeqNo(10L).setIfPrimaryTerm(20);try {IndexResponse response = client.index(request, RequestOptions.DEFAULT);} catch(ElasticsearchException e) {if (e.status() == RestStatus.CONFLICT) {//<1>}}

<1> 引发异常指示返回版本冲突错误

在设置为且已存在具有相同索引和 ID 的文档的情况下，将发生相同的情况： opTypecreate

IndexRequest request = new IndexRequest("posts").id("1").source("field", "value").opType(DocWriteRequest.OpType.CREATE);try {IndexResponse response = client.index(request, RequestOptions.DEFAULT);} catch(ElasticsearchException e) {if (e.status() == RestStatus.CONFLICT) {//<1>}}

<1>引发异常指示返回版本冲突错误

5.2 获取Api (Get API)
5.2.1 案例：

private static void test01(){RestHighLevelClient client = new RestHighLevelClient(RestClient.builder(new HttpHost("127.0.0.1",9200)));GetRequest request = new GetRequest("student");// 为特定字段 配置源包含String[] includs = {"name","id","content"};String[] excluds = {"id"};FetchSourceContext context = new FetchSourceContext(true,includs,excluds);request.id("1").version(2).fetchSourceContext(context);try {GetResponse documentFields = client.get(request, RequestOptions.DEFAULT);if (documentFields.isExists()) {//检索名称System.out.println(documentFields.getIndex());// 获取文档源的 Map 结果System.out.println(documentFields.getSource());// 获取源作为 MapSystem.out.println(documentFields.getSourceAsMap());// 获取源作为 bytesSystem.out.println(documentFields.getSourceAsBytes());}else {System.out.println("不错在该数据");}} catch (IOException e) {e.printStackTrace();}}

5.2.2 获取请求

需要以下参数：GetRequest

GetRequest getRequest = new GetRequest("posts", //<1>"1");//<1>

<1> 索引名称

<2> 文档 ID

5.2.3 可选参数

可以选择提供以下参数：

request.fetchSourceContext(FetchSourceContext.DO_NOT_FETCH_SOURCE);

禁用源检索，默认情况下启用

String[] includes = new String[]{"message", "*Date"};String[] excludes = Strings.EMPTY_ARRAY;FetchSourceContext fetchSourceContext = new FetchSourceContext(true, includes, excludes);request.fetchSourceContext(fetchSourceContext);

为特定字段配置源包含

includes : 检索结果所包含的字段excludes : 检索结果排除的字段

String[] includes = Strings.EMPTY_ARRAY;String[] excludes = new String[]{"message"};FetchSourceContext fetchSourceContext =new FetchSourceContext(true, includes, excludes);request.fetchSourceContext(fetchSourceContext);

为特定字段配置源排除

request.storedFields("message");GetResponse getResponse = client.get(request, RequestOptions.DEFAULT);String message = getResponse.getField("message").getValue();