Projeto final do curso

import com.google.gson.Gson;
import com.google.gson.GsonBuilder;

import java.io.IOException;
import java.net.URI;
import java.net.http.HttpClient;
import java.net.http.HttpRequest;
import java.net.http.HttpResponse;

public class ConsultaCep {

    public Endereco buscaEndereco(String cep) {
        URI endereco = URI.create("https://viacep.com.br/ws/" + cep + "/json");

        HttpRequest request = HttpRequest.newBuilder()
                .uri(endereco)
                .build();

        try {
            HttpResponse<String> response = HttpClient
                    .newHttpClient()
                    .send(request, HttpResponse.BodyHandlers.ofString());
            return new Gson().fromJson(response.body(), Endereco.class);
        } catch (Exception e) {
            throw new RuntimeException("Endereço não encontrado!");
        }
    }
}

public record Endereco(String cep, String logradouro, String complemento, String localidade, String uf) {
}

import com.google.gson.Gson;
import com.google.gson.GsonBuilder;

import java.io.FileWriter;
import java.io.IOException;

public class GeradorDeArquivo {

    public void salvaJson(Endereco endereco) throws IOException {
        Gson gson = new GsonBuilder().setPrettyPrinting().create();
        FileWriter escrita = new FileWriter(endereco.cep() + ".json");
        escrita.write(gson.toJson(endereco));
        escrita.close();
    }
}

import java.io.IOException;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {

        Scanner scanner = new Scanner(System.in);
        ConsultaCep consultaCep = new ConsultaCep();

        System.out.println("Digite o CEP: ");
        String cep = scanner.nextLine();

        try {
            Endereco novoEndereco = consultaCep.buscaEndereco(cep);
            System.out.println(novoEndereco);
            GeradorDeArquivo gerador = new GeradorDeArquivo();
            gerador.salvaJson(novoEndereco);
        } catch (RuntimeException | IOException e) {
            System.out.println(e.getMessage());
            System.out.println("Fim");
        }
    }
}