Elasticsearch from Java Programming

In the last chapter, we used aggregation frameworks to explore data analysis. We drew the Bollinger Band for one of the exchange-traded funds (ETFs) to demonstrate operational data analysis daily. We also examined the role of Elasticsearch in sentiment analysis and showed how a number of different open source projects integrated Elasticsearch into the analysis. In this chapter, we will focus on the basics of two supported Java REST clients. We’ll also explore the main features and operations for each approach. The advantage of using a REST client is that it accepts the request objects or the response objects as arguments in the APIs. The high-level REST client is responsible for the corresponding serialization and deserialization. If we choose the low-level REST client, we need to handle such operations by ourselves. Each API can be called...