ElasticSearch异步创建索引报错，Connection closed unexpectedly，同步创建就没有问题

@Service
public class EsApiServiceImpl implements EsApiService {

@Autowired
private RestHighLevelClient client;

private static ObjectMapper mapper = new ObjectMapper();

@Override
public IndexResponse createIndex() {
Map<String, Object> jsonMap = new HashMap<>();
jsonMap.put("user", "kimchy");
jsonMap.put("postDate", new Date());
jsonMap.put("message", "trying out Elasticsearch");

// 索引名,文档id,文档
IndexRequest request = new IndexRequest("index-8").id("1").source(jsonMap);

// 可选参数
// routing默认是null
String routing = request.routing();
request.routing(routing);
System.out.println("默认routing是: " + routing);
// Timeout to wait for primary shard to become available as a TimeValue
request.timeout(TimeValue.timeValueSeconds(1));
// 刷新策略,参考https://blog.csdn.net/hanchao5 ... 51166
request.setRefreshPolicy(WriteRequest.RefreshPolicy.WAIT_UNTIL);
request.opType(DocWriteRequest.OpType.CREATE);
IndexResponse response = null;
try {
response = client.index(request, RequestOptions.DEFAULT);
System.out.println("Result is: " + JsonParser.bean2Json(response));
} catch (IOException e) {
e.printStackTrace();
}
return response;
}

@Override
public void createIndexAsync() {
Map<String, Object> jsonMap = new HashMap<>();
jsonMap.put("user", "kimchy");
jsonMap.put("postDate", new Date());
jsonMap.put("message", "trying out Elasticsearch");

// 索引名,文档id,文档
IndexRequest request = new IndexRequest("index-9").id("1").source(jsonMap);

// listener用于成功或失败的回调
ActionListener<IndexResponse> listener = new ActionListener<IndexResponse>() {
@Override
public void onResponse(IndexResponse indexResponse) {
System.out.println("Result is: " + JsonParser.bean2Json(indexResponse));
}

@Override
public void onFailure(Exception e) {
System.out.println("Exception is: " + e.getMessage());
}
};

client.indexAsync(request, RequestOptions.DEFAULT, listener);
}
}