Update 6 files

- /src/main/Resources/application.yml
- /src/main/config/AppProperties.java
- /src/main/service/ExternalApiService.java
- /src/main/controller/GenerateController.java
- /src/test/AppPropertiesTest.java
- /README.md

README.md

@@ -88,6 +88,27 @@ Show your appreciation to those who have contributed to the project.
 
 ## License
 For open source projects, say how it is licensed.
+---
 
-## Project status
-If you have run out of energy or time for your project, put a note at the top of the README saying that development has slowed down or stopped completely. Someone may choose to fork your project or volunteer to step in as a maintainer or owner, allowing your project to keep going. You can also make an explicit request for maintainers.
+## Sprint 4 – Secure API Key Management
+
+In Sprint 4, secure handling of API keys was implemented for the V2D (Video to Document) framework.
+
+### Implementation Overview
+- API keys are **not stored in the source code**
+- The backend loads the key from an **environment variable**
+- A single configuration works for all users without manual setup
+- Secrets are protected from being exposed in the repository or frontend
+
+### Configuration
+The backend expects the following environment variable:
+
+
+This variable is injected at runtime by the deployment or CI/CD environment and referenced in `application.yml`.
+
+### Security Benefits
+- Prevents accidental exposure of API keys
+- Ensures secure collaboration in GitLab
+- Follows best practices for secret management
+
+---

src/main/Resources/application.yml

@@ -0,0 +1,7 @@
+spring:
+  application:
+    name: v2d-document
+
+app:
+  external:
+    apiKey: ${LLM_API_KEY:}

src/main/config/AppProperties.java

@@ -0,0 +1,13 @@
+package com.v2d.document.config;
+
+import org.springframework.boot.context.properties.ConfigurationProperties;
+import org.springframework.context.annotation.Configuration;
+
+@Configuration
+@ConfigurationProperties(prefix = "app.external")
+public class AppProperties {
+    private String apiKey;
+
+    public String getApiKey() { return apiKey; }
+    public void setApiKey(String apiKey) { this.apiKey = apiKey; }
+}

src/main/controller/GenerateController.java

@@ -0,0 +1,26 @@
+package com.v2d.document.controller;
+
+import com.v2d.document.service.ExternalApiService;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.*;
+
+import java.util.Map;
+
+@RestController
+@RequestMapping("/api/generate")
+public class GenerateController {
+
+    private final ExternalApiService externalApiService;
+
+    public GenerateController(ExternalApiService externalApiService) {
+        this.externalApiService = externalApiService;
+    }
+
+    @PostMapping
+    public ResponseEntity<String> generate(@RequestBody Map<String,Object> body) {
+        // Build provider payload from the user's body (transform safely)
+        String payload = "{\"text\": \"use this text\"}"; // adapt for real usage
+        String providerResponse = externalApiService.callProvider(payload);
+        return ResponseEntity.ok(providerResponse);
+    }
+}

src/main/service/ExternalApiService.java

@@ -0,0 +1,90 @@
+package com.v2d.document.service;
+
+import com.v2d.document.config.AppProperties;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.stereotype.Service;
+
+import java.net.URI;
+import java.net.http.HttpClient;
+import java.net.http.HttpRequest;
+import java.net.http.HttpResponse;
+
+@Service
+public class ExternalApiService {
+    private final Logger log = LoggerFactory.getLogger(ExternalApiService.class);
+    private final AppProperties props;
+    private final HttpClient http = HttpClient.newHttpClient();
+
+    public ExternalApiService(AppProperties props) {
+        this.props = props;
+    }
+
+    public String callProvider(String jsonPayload) {
+        String key = props.getApiKey();
+        if (key == null || key.isBlank()) {
+            log.warn("External API key is not configured.");
+            throw new IllegalStateException("External API key missing");
+        }
+
+        try {
+            HttpRequest req = HttpRequest.newBuilder()
+                    .uri(URI.create("https://api.example.com/endpoint")) // replace with real endpoint
+                    .header("Authorization", "Bearer " + key)
+                    .header("Content-Type", "application/json")
+                    .POST(HttpRequest.BodyPublishers.ofString(jsonPayload))
+                    .build();
+
+            HttpResponse<String> resp = http.send(req, HttpResponse.BodyHandlers.ofString());
+            return resp.body();
+        } catch (Exception e) {
+            log.error("External API call failed: {}", e.getMessage());
+            throw new RuntimeException("External API call failed", e);
+        }
+    }
+}
+package com.v2d.document.service;
+
+import com.v2d.document.config.AppProperties;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.stereotype.Service;
+
+import java.net.URI;
+import java.net.http.HttpClient;
+import java.net.http.HttpRequest;
+import java.net.http.HttpResponse;
+
+@Service
+public class ExternalApiService {
+    private final Logger log = LoggerFactory.getLogger(ExternalApiService.class);
+    private final AppProperties props;
+    private final HttpClient http = HttpClient.newHttpClient();
+
+    public ExternalApiService(AppProperties props) {
+        this.props = props;
+    }
+
+    public String callProvider(String jsonPayload) {
+        String key = props.getApiKey();
+        if (key == null || key.isBlank()) {
+            log.warn("External API key is not configured.");
+            throw new IllegalStateException("External API key missing");
+        }
+
+        try {
+            HttpRequest req = HttpRequest.newBuilder()
+                    .uri(URI.create("https://api.example.com/endpoint")) // replace with real endpoint
+                    .header("Authorization", "Bearer " + key)
+                    .header("Content-Type", "application/json")
+                    .POST(HttpRequest.BodyPublishers.ofString(jsonPayload))
+                    .build();
+
+            HttpResponse<String> resp = http.send(req, HttpResponse.BodyHandlers.ofString());
+            return resp.body();
+        } catch (Exception e) {
+            log.error("External API call failed: {}", e.getMessage());
+            throw new RuntimeException("External API call failed", e);
+        }
+    }
+}

src/test/AppPropertiesTest.java

@@ -0,0 +1,20 @@
+package com.v2d.document.config;
+
+import org.junit.jupiter.api.Test;
+import org.springframework.boot.test.context.runner.ApplicationContextRunner;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class AppPropertiesTest {
+    private final ApplicationContextRunner contextRunner = new ApplicationContextRunner()
+            .withUserConfiguration(AppProperties.class)
+            .withPropertyValues("app.external.apiKey=TEST_KEY");
+
+    @Test
+    void bindsApiKey() {
+        contextRunner.run(context -> {
+            AppProperties props = context.getBean(AppProperties.class);
+            assertThat(props.getApiKey()).isEqualTo("TEST_KEY");
+        });
+    }
+}