Security

Are you handling sensitive data correctly? Are your dependencies upto-date? Check the important areas of your code again.

Security should be part of every commit. Handling sensitive data correctly, validating inputs, and keeping dependencies up-to-date are non-negotiable. One careless method can create vulnerabilities that are hard to fix later.

For example, storing passwords in plain text is unsafe:

public class UserService {
    public void saveUser(String username, String password) {
        database.save(username, password); // unsafe!
    }
}

Refactor using Spring Security’s BCryptPasswordEncoder, a current and maintained library:

import org.springframework.security.crypto.password.Pbkdf2PasswordEncoder;

public class UserService {
    private final Pbkdf2PasswordEncoder passwordEncoder =
    new Pbkdf2PasswordEncoder(
        "secret",16,600_000,
        Pbkdf2PasswordEncoder.SecretKeyFactoryAlgorithm.PBKDF2WithHmacSHA256
    );

    public void saveUser(String username, String password) {
        String hashedPassword = passwordEncoder.encode(password);
        database.save(username, hashedPassword);
    }

    public boolean checkPassword(String password, String storedHash) {
        return passwordEncoder.matches(password, storedHash);
    }
}

Here:

encode hashes the password with a strong salt.
matches safely verifies user input against the stored hash.

Practical habits for secure code:

Never store sensitive information in plain text.
Validate all user inputs; never trust external data.
Use well-maintained libraries like Spring Security for cryptography.
Keep dependencies up-to-date and monitor for vulnerabilities.
Limit access to sensitive methods and data with proper access control.

Every commit should ask: “Could this expose sensitive data or create a vulnerability?” Using modern, maintained libraries and secure patterns consistently keeps your code safe and maintainable.