How to Read Files in Spring Boot: A Guide to Secure and Efficient Methods

Reading files in a Spring Boot application is a common task. Whether you are working with configuration files, resource files, or files uploaded by users, it’s essential to ensure that your approach is both efficient and secure.

1. Reading Files from the resources Folder

Spring Boot applications typically include files like application.properties, templates, and static resources in the src/main/resources directory. To read files from this folder:

Using ClassPathResource

This method is simple and effective for reading static resources packaged within the application.

import org.springframework.core.io.ClassPathResource;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.stream.Collectors;

public class FileReaderExample {
    public String readFileFromResources(String fileName) throws Exception {
        ClassPathResource resource = new ClassPathResource(fileName);
        try (BufferedReader reader = new BufferedReader(new InputStreamReader(resource.getInputStream()))) {
            return reader.lines().collect(Collectors.joining("\n"));
        }
    }
}

Advantages:

• Works seamlessly…