basic auth implemented for generate request

src/main/java/io/github/amithkoujalgi/ollama4j/core/OllamaAPI.java

@@ -37,6 +37,8 @@ public class OllamaAPI {
   private final String host;
   private long requestTimeoutSeconds = 3;
   private boolean verbose = true;
+  private String username;
+  private String password;
 
   /**
    * Instantiates the Ollama API.
@@ -64,6 +66,14 @@ public class OllamaAPI {
     this.verbose = verbose;
   }
 
+  /**
+   *
+   */
+  public void setBasicAuth(String username, String password) {
+    this.username = username;
+    this.password = password;
+  }
+
   /**
    * API to check the reachability of Ollama server.
    *
@@ -426,14 +436,18 @@ public class OllamaAPI {
     long startTime = System.currentTimeMillis();
     HttpClient httpClient = HttpClient.newHttpClient();
     URI uri = URI.create(this.host + "/api/generate");
-    HttpRequest request =
+    HttpRequest.Builder requestBuilder =
         HttpRequest.newBuilder(uri)
             .POST(
                 HttpRequest.BodyPublishers.ofString(
                     Utils.getObjectMapper().writeValueAsString(ollamaRequestModel)))
             .header("Content-Type", "application/json")
-            .timeout(Duration.ofSeconds(requestTimeoutSeconds))
-            .build();
+            .timeout(Duration.ofSeconds(requestTimeoutSeconds));
+    if (basicAuthCredentialsSet()) {
+      requestBuilder.header("Authorization", getBasicAuthHeaderValue());
+    }
+    HttpRequest request = requestBuilder.build();
+    logger.debug("Ask model '" + ollamaRequestModel + "' ...");
     HttpResponse<InputStream> response =
         httpClient.send(request, HttpResponse.BodyHandlers.ofInputStream());
     int statusCode = response.statusCode();
@@ -444,10 +458,16 @@ public class OllamaAPI {
       String line;
       while ((line = reader.readLine()) != null) {
         if (statusCode == 404) {
+          logger.warn("Status code: 404 (Not Found)");
           OllamaErrorResponseModel ollamaResponseModel =
               Utils.getObjectMapper().readValue(line, OllamaErrorResponseModel.class);
           responseBuffer.append(ollamaResponseModel.getError());
-        } else {
+        } else if (statusCode == 401) {
+          logger.warn("Status code: 401 (Unauthorized)");
+          OllamaErrorResponseModel ollamaResponseModel =
+                  Utils.getObjectMapper().readValue("{\"error\":\"Unauthorized\"}", OllamaErrorResponseModel.class);
+          responseBuffer.append(ollamaResponseModel.getError());
+        }else {
           OllamaResponseModel ollamaResponseModel =
               Utils.getObjectMapper().readValue(line, OllamaResponseModel.class);
           if (!ollamaResponseModel.isDone()) {
@@ -457,10 +477,30 @@ public class OllamaAPI {
       }
     }
     if (statusCode != 200) {
+      logger.error("Status code " + statusCode + " instead 200");
       throw new OllamaBaseException(responseBuffer.toString());
     } else {
       long endTime = System.currentTimeMillis();
       return new OllamaResult(responseBuffer.toString().trim(), endTime - startTime, statusCode);
     }
   }
+
+  /**
+   * @return basic authentication header value (encoded credentials)
+   */
+  private String getBasicAuthHeaderValue() {
+    String credentialsToEncode = username + ":" + password;
+    return "Basic " + Base64.getEncoder().encodeToString(credentialsToEncode.getBytes());
+  }
+
+  /**
+   * @return true when Basic Auth credentials set
+   */
+  private boolean basicAuthCredentialsSet() {
+    if (username != null && password !=  null) {
+      return true;
+    } else {
+      return false;
+    }
+  }
 }