Spring boot, Spring data JPA, MySql and java to read csv file and save into database.

Introduction

In this tutorial, we will explore how to use Spring Boot, Spring Data JPA, MySQL, and Java to read a CSV file and save its contents into a MySQL database. This process will help streamline your data ingestion workflows, making it easier to manage and utilize data from CSV files in your applications.

Step 1: Set Up Your Project

• Create a new Spring Boot project using Spring Initializr (https://start.spring.io).
• Add the following dependencies:
  • Spring Web
  • Spring Data JPA
  • MySQL Driver
• Generate the project and open it in your favorite IDE.

Step 2: Configure MySQL Database

• Install MySQL and create a new database for your application.
• Update the application.properties file in your Spring Boot project with the following configuration:

spring.datasource.url=jdbc:mysql://localhost:3306/your_database_name
spring.datasource.username=your_username
spring.datasource.password=your_password
spring.jpa.hibernate.ddl-auto=update

Step 3: Create Entity Classes

• Define entity classes that map to your CSV data. Use JPA annotations to specify the entity properties. For example:

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;

@Entity
public class YourEntity {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
    private String field1;
    private String field2;
    // Getters and Setters
}

Step 4: Create Repository Interfaces

• Create a repository interface that extends JpaRepository for your entity. This provides built-in CRUD operations.

import org.springframework.data.jpa.repository.JpaRepository;

public interface YourEntityRepository extends JpaRepository<YourEntity, Long> {
}

Step 5: Read CSV File

• Use Java's built-in I/O classes to read the CSV file. Here is an example of how to do this:

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;

public void readCsv(String filePath) {
    try (BufferedReader br = new BufferedReader(new FileReader(filePath))) {
        String line;
        while ((line = br.readLine()) != null) {
            String[] values = line.split(",");
            // Map values to YourEntity and save to database
        }
    } catch (IOException e) {
        e.printStackTrace();
    }
}

Step 6: Save Data to Database

• Inside your CSV reading method, create a new instance of your entity and save it using the repository. Example:

YourEntity entity = new YourEntity();
entity.setField1(values[0]);
entity.setField2(values[1]);
yourEntityRepository.save(entity);

Step 7: Handle Exceptions

• Implement error handling to manage potential issues during CSV file reading or database operations. Use try-catch blocks and log the errors appropriately.

Step 8: Run the Application

• Start your Spring Boot application and run the method that reads the CSV file.
• Verify that the data is correctly saved in the MySQL database.

Conclusion

In this tutorial, we covered how to set up a Spring Boot application to read CSV files and save the data into a MySQL database using Spring Data JPA. You learned how to configure your project, create entities and repositories, read from a CSV file, and handle exceptions. As a next step, consider exploring additional features of Spring Data JPA or enhancing your application with further functionalities like data validation or REST API integration. Happy coding!