issues/2334 | sample spring elastic app

* added readme file

Signed-off-by: Snoopy009 <[email protected]>

Author: Yordaniss

spring-elastic/README.md

@@ -0,0 +1,145 @@
+# Spring Boot Elasticsearch Example
+
+This project is a simple Spring Boot application that demonstrates how to integrate with Elasticsearch using the Java High-Level REST Client. It provides REST endpoints to create and search books in an Elasticsearch index.
+
+## Prerequisites
+
+- **Java Development Kit (JDK) 8 or higher**
+- **Maven** for building the project
+- **Docker** for running Elasticsearch
+- An API client like **Postman** or **cURL** for testing endpoints
+
+## Setting Up Elasticsearch with Docker
+
+To run Elasticsearch, we'll use Docker to pull and run the official Elasticsearch image.
+
+Execute the following command in your terminal:
+
+```bash
+docker run -d \
+  -p 9200:9200 \
+  -p 9300:9300 \
+  --name elasticsearch \
+  -e "discovery.type=single-node" \
+  -e "xpack.security.enabled=false" \
+  docker.elastic.co/elasticsearch/elasticsearch:8.15.2
+```
+
+## Explanation of the Docker Command:
+
+- `-d`: Run the container in detached mode (in the background).
+- `-p 9200:9200`: Map port 9200 of the host to port 9200 of the container (HTTP API).
+- `-p 9300:9300`: Map port 9300 of the host to port 9300 of the container (Transport API).
+- `--name elasticsearch`: Assign the name "elasticsearch" to the container.
+- `-e "discovery.type=single-node"`: Run Elasticsearch in single-node mode.
+- `-e "xpack.security.enabled=false"`: Disable X-Pack security features for simplicity. !!! Not recommended for production
+- `docker.elastic.co/elasticsearch/elasticsearch:8.15.2`: The Docker image to use.
+
+### Verify Elasticsearch is Running:
+
+After running the Docker command, verify that Elasticsearch is running by accessing [http://localhost:9200](http://localhost:9200) in your browser or using `curl`:
+
+```bash
+curl http://localhost:9200
+```
+
+You should receive a JSON response with cluster information.
+
+Running the Spring Boot Application
+1. Clone the Repository
+
+```bash
+git clone https://github.com/yourusername/your-repo-name.git
+cd your-repo-name
+```
+
+2. Configure Application Properties
+   Ensure that your application.properties file is correctly set up. It should be located in src/main/resources/ and contain the following properties:
+
+```bash
+spring.application.name=spring-elastic
+server.port=8081
+
+spring.elasticsearch.url=localhost
+spring.elasticsearch.port=9200
+
+# Credentials are optional if security is disabled
+spring.elasticsearch.username=
+spring.elasticsearch.password=
+```
+3. Build the Project
+   Use Maven to build the project:
+
+```bash
+mvn clean install
+```
+
+4. Run the Application
+   You can run the application using Maven:
+
+
+```bash
+mvn spring-boot:run
+```
+
+Or run the generated JAR file:
+
+```bash
+java -jar target/your-app-name.jar
+```
+The application will start on port 8081.
+
+Project Structure
+- Controller
+BookController: Handles HTTP requests for creating and searching books.
+- Model
+Book: Represents the book entity stored in Elasticsearch.
+- Client
+BookElasticsearchClient: Manages the connection to Elasticsearch.
+- Service
+BookElasticsearchService: Contains business logic for interacting with Elasticsearch.
+Endpoints
+1. Create a Book
+   - URL: /book/create
+   - Method: POST
+   - Description: Creates a new book in the Elasticsearch index.
+   - Request Body:
+
+```bash
+{
+  "id": "1",
+  "name": "Elasticsearch Basics",
+  "description": "An introductory guide to Elasticsearch.",
+  "price": 29.99
+}
+```
+Sample cURL Request:
+
+```bash
+curl -X POST \
+  http://localhost:8081/book/create \
+  -H 'Content-Type: application/json' \
+  -d '{
+        "id": "1",
+        "name": "Elasticsearch Basics",
+        "description": "An introductory guide to Elasticsearch.",
+        "price": 29.99
+      }'
+```
+
+2. Find Books by Name
+   - URL: /book/find_by_name
+   - Method: GET
+   - Description: Searches for books by name in the Elasticsearch index.
+   - Query Parameter:
+      - name: The name or partial name of the book to search for.
+```bash
+curl -X GET "http://localhost:8081/book/find_by_name?name=Elasticsearch"
+```
+
+### Conclusion
+You have successfully set up an Elasticsearch instance using Docker and run a Spring Boot application that interacts with it. This application demonstrates basic CRUD operations with Elasticsearch, providing a foundation for more complex integrations.
+
+Feel free to extend this application by adding more features like update and delete operations, or by integrating authentication and security features.
+
+Note: In a production environment, you should enable security features in Elasticsearch and handle credentials appropriately.