feat(java): switch api key helper

Author: Fluf22

clients/algoliasearch-client-java/algoliasearch/src/main/java/com/algolia/ApiClient.java

@@ -24,7 +24,7 @@
  */
 public abstract class ApiClient implements Closeable {
 
-  private final Requester requester;
+  protected final Requester requester;
   private final ExecutorService executor;
 
   /** Constructs a new instance of the {@link ApiClient}. */

clients/algoliasearch-client-java/algoliasearch/src/main/java/com/algolia/config/Requester.java

@@ -31,4 +31,8 @@ public interface Requester extends Closeable {
    * @return The deserialized response.
    */
   <T> T execute(HttpRequest httpRequest, RequestOptions requestOptions, TypeReference<?> returnType);
+
+  default void setApiKey(String apiKey) {
+    System.out.println("Nothing to do here");
+  }
 }

clients/algoliasearch-client-java/algoliasearch/src/main/java/com/algolia/internal/HttpRequester.java

@@ -60,6 +60,11 @@ public <T> T execute(HttpRequest httpRequest, RequestOptions requestOptions, Typ
     return execute(httpRequest, requestOptions, serializer.getJavaType(returnType));
   }
 
+  @Override
+  public void setApiKey(@Nonnull String apiKey) {
+    this.httpClient.interceptors().add(new HeaderInterceptor(Collections.singletonMap("X-Algolia-API-Key", apiKey)));
+  }
+
   /** Core method to execute an HTTP request and handle the response. */
   private <T> T execute(@Nonnull HttpRequest httpRequest, RequestOptions requestOptions, JavaType returnType) {
     if (isClosed.get()) {

templates/java/api.mustache

@@ -130,6 +130,15 @@ public class {{classname}} extends ApiClient {
     }
     {{/hostsWithoutVariables.size}}
 
+  /**
+   * Helper method to switch the API key used to authenticate the requests.
+   * 
+   * @param apiKey The new API key to be used from now on.
+   */
+  public void setApiKey(@Nonnull String apiKey) {
+    this.requester.setApiKey(apiKey);
+  }
+
     {{#operation}}
     /**
      * {{{notes}}}{{#allParams}}