NUHMAN.com

To make a call to a website that requires username, password, and a token-based authentication (like JWT), you'll typically follow these steps:

✅ 1. Login to the Website and Get a Token

You send a POST request with username and password, and receive a token (commonly JWT) in return.

java

import org.springframework.http.*;
import org.springframework.web.client.RestTemplate;

import java.util.HashMap;
import java.util.Map;

public class AuthService {

    private final RestTemplate restTemplate = new RestTemplate();

    public String loginAndGetToken(String loginUrl, String username, String password) {
        // Create the login request body
        Map<String, String> loginRequest = new HashMap<>();
        loginRequest.put("username", username);
        loginRequest.put("password", password);

        // Set headers
        HttpHeaders headers = new HttpHeaders();
        headers.setContentType(MediaType.APPLICATION_JSON);

        // Wrap body and headers into entity
        HttpEntity<Map<String, String>> request = new HttpEntity<>(loginRequest, headers);

        // Make the request
        ResponseEntity<String> response = restTemplate.exchange(loginUrl, HttpMethod.POST, request, String.class);

        // Extract token from response (simplified)
        return extractTokenFromResponse(response.getBody());
    }

    private String extractTokenFromResponse(String responseBody) {
        // Simplified: Use a JSON library like Jackson or Gson in real code
        return "your-jwt-token";
    }
}

✅ 2. Use the Token for Authenticated API Calls

Use the received token to access protected endpoints.

java

public class ApiService {

    private final RestTemplate restTemplate = new RestTemplate();

    public String callApiWithToken(String apiUrl, String token) {
        HttpHeaders headers = new HttpHeaders();
        headers.set("Authorization", "Bearer " + token);

        HttpEntity<String> request = new HttpEntity<>(headers);

        ResponseEntity<String> response = restTemplate.exchange(apiUrl, HttpMethod.GET, request, String.class);

        return response.getBody();
    }
}

✅ 3. Putting It All Together

java

public class Application {

    public static void main(String[] args) {
        AuthService authService = new AuthService();
        ApiService apiService = new ApiService();

        String loginUrl = "https://example.com/api/login";
        String username = "your-username";
        String password = "your-password";

        String token = authService.loginAndGetToken(loginUrl, username, password);

        String apiUrl = "https://example.com/api/data";
        String response = apiService.callApiWithToken(apiUrl, token);

        System.out.println("API Response: " + response);
    }
}

🔍 Explanation

• Login Request: A POST request is sent to the login URL with the user's credentials.
• Token Extraction: The response is parsed to extract the authentication token.
• Authenticated API Call: The token is passed in the Authorization header using the Bearer schema.