Mods to change HookManager into an interface.

src/main/java/org/gitlab4j/api/HookManager.java

@@ -4,37 +4,23 @@ package org.gitlab4j.api;
 import javax.servlet.http.HttpServletRequest;
 
 /**
- * This class provides a base class handler for processing GitLab Web Hook and System Hook callouts.
+ * This interface provides a base class handler for processing GitLab Web Hook and System Hook callouts.
  */
-public abstract class HookManager {
-
-    private String secretToken;
-
-    /**
-     * Create a HookManager to handle GitLab hook events.
-     */
-    public HookManager() {
-        this.secretToken = null;
-    }
+public interface HookManager {
 
     /**
-     * Create a HookManager to handle GitLab hook events which will be verified
-     * against the specified secretToken.
-     * 
-     * @param secretToken the secret token to verify against
+     * Get the secret token that received hook events should be validated against.
+     *
+     * @return the secret token that received hook events should be validated against
      */
-    public HookManager(String secretToken) {
-        this.secretToken = secretToken;
-    }
+    String getSecretToken();
 
     /**
      * Set the secret token that received hook events should be validated against.
      *
      * @param secretToken the secret token to verify against
      */
-    public void setSecretToken(String secretToken) {
-        this.secretToken = secretToken;
-    }
+    void setSecretToken(String secretToken);
 
     /**
      * Validate the provided secret token against the reference secret token. Returns true if
@@ -44,8 +30,11 @@ public abstract class HookManager {
      * @param secretToken the token to validate
      * @return true if the secret token is valid or there is no reference secret token to validate against
      */
-    public boolean isValidSecretToken(String secretToken) {
-        return (this.secretToken == null || this.secretToken.equals(secretToken) ? true : false);
+    default public boolean isValidSecretToken(String secretToken) {
+        String ourSecretToken = getSecretToken();
+        return (ourSecretToken == null ||
+                ourSecretToken.trim().isEmpty() ||
+                ourSecretToken.equals(secretToken) ? true : false);
     }
 
     /**
@@ -56,9 +45,9 @@ public abstract class HookManager {
      * @param request the HTTP request to verify the secret token
      * @return true if the secret token is valid or there is no reference secret token to validate against
      */
-    public boolean isValidSecretToken(HttpServletRequest request) {
+    default public boolean isValidSecretToken(HttpServletRequest request) {
 
-        if (this.secretToken != null) {
+        if (getSecretToken() != null) {
             String secretToken = request.getHeader("X-Gitlab-Token");
             return (isValidSecretToken(secretToken));
         }
@@ -73,5 +62,5 @@ public abstract class HookManager {
      * @param request the HttpServletRequest to read the Event instance from
      * @throws GitLabApiException if the parsed event is not supported
      */
-    public abstract void handleEvent(HttpServletRequest request) throws GitLabApiException;
+    public void handleEvent(HttpServletRequest request) throws GitLabApiException;
 }
\ No newline at end of file

src/main/java/org/gitlab4j/api/systemhooks/SystemHookManager.java

@@ -21,7 +21,7 @@ import com.fasterxml.jackson.databind.node.ObjectNode;
 /**
  * This class provides a handler for processing GitLab System Hook callouts.
  */
-public class SystemHookManager extends HookManager {
+public class SystemHookManager implements HookManager {
 
     public static final String SYSTEM_HOOK_EVENT = "System Hook";
     private final static Logger LOGGER = GitLabApi.getLogger();
@@ -30,37 +30,69 @@ public class SystemHookManager extends HookManager {
     // Collection of objects listening for System Hook events.
     private final List<SystemHookListener> systemHookListeners = new CopyOnWriteArrayList<SystemHookListener>();
 
+    private String secretToken;
+
     /**
      * Create a HookManager to handle GitLab system hook events.
      */
     public SystemHookManager() {
-        super();
     }
 
     /**
      * Create a HookManager to handle GitLab system hook events which will be verified
      * against the specified secretToken.
-     * 
+     *
      * @param secretToken the secret token to verify against
      */
     public SystemHookManager(String secretToken) {
-        super(secretToken);
-    }
+        this.secretToken = secretToken;
+     }
+
+     /**
+      * Get the secret token that received hook events should be validated against.
+      *
+      * @return the secret token that received hook events should be validated against
+      */
+     public String getSecretToken() {
+         return (secretToken);
+     }
+
+     /**
+      * Set the secret token that received hook events should be validated against.
+      *
+      * @param secretToken the secret token to verify against
+      */
+     public void setSecretToken(String secretToken) {
+         this.secretToken = secretToken;
+     }
 
     /**
      * Parses and verifies an SystemHookEvent instance from the HTTP request and
      * fires it off to the registered listeners.
-     * 
+     *
      * @param request the HttpServletRequest to read the Event instance from
      * @throws GitLabApiException if the parsed event is not supported
      */
     public void handleEvent(HttpServletRequest request) throws GitLabApiException {
+        handleRequest(request);
+    }
+
+    /**
+     * Parses and verifies an SystemHookEvent instance from the HTTP request and
+     * fires it off to the registered listeners.
+     *
+     * @param request the HttpServletRequest to read the Event instance from
+     * @return the processed SystemHookEvent instance read from the request,null if the request
+     * not contain a system hook event
+     * @throws GitLabApiException if the parsed event is not supported
+     */
+    public SystemHookEvent handleRequest(HttpServletRequest request) throws GitLabApiException {
 
         String eventName = request.getHeader("X-Gitlab-Event");
         if (eventName == null || eventName.trim().isEmpty()) {
             String message = "X-Gitlab-Event header is missing!";
             LOGGER.warning(message);
-            return;
+            return (null);
         }
 
         if (!isValidSecretToken(request)) {
@@ -126,6 +158,7 @@ public class SystemHookManager extends HookManager {
             event.setRequestUrl(requestUrl != null ? requestUrl.toString() : null);
             event.setRequestQueryString(request.getQueryString());
             fireEvent(event);
+            return (event);
 
         } catch (Exception e) {
             LOGGER.warning("Error processing JSON data, exception=" +

src/main/java/org/gitlab4j/api/webhook/WebHookManager.java

@@ -18,7 +18,7 @@ import org.gitlab4j.api.utils.JacksonJson;
 /**
  * This class provides a handler for processing GitLab WebHook callouts.
  */
-public class WebHookManager extends HookManager {
+public class WebHookManager implements HookManager {
 
     private final static Logger LOGGER = GitLabApi.getLogger();
     private final JacksonJson jacksonJson = new JacksonJson();
@@ -26,11 +26,12 @@ public class WebHookManager extends HookManager {
     // Collection of objects listening for WebHook events.
     private final List<WebHookListener> webhookListeners = new CopyOnWriteArrayList<WebHookListener>();
 
+    private String secretToken;
+
     /**
      * Create a HookManager to handle GitLab webhook events.
      */
     public WebHookManager() {
-        super();
     }
 
     /**
@@ -40,7 +41,25 @@ public class WebHookManager extends HookManager {
      * @param secretToken the secret token to verify against
      */
     public WebHookManager(String secretToken) {
-        super(secretToken);
+        this.secretToken = secretToken;
+    }
+
+    /**
+     * Get the secret token that received hook events should be validated against.
+     *
+     * @return the secret token that received hook events should be validated against
+     */
+    public String getSecretToken() {
+        return (secretToken);
+    }
+
+    /**
+     * Set the secret token that received hook events should be validated against.
+     *
+     * @param secretToken the secret token to verify against
+     */
+    public void setSecretToken(String secretToken) {
+        this.secretToken = secretToken;
     }
 
     /**
@@ -51,11 +70,24 @@ public class WebHookManager extends HookManager {
      * @throws GitLabApiException if the parsed event is not supported
      */
     public void handleEvent(HttpServletRequest request) throws GitLabApiException {
+        handleRequest(request);
+    }
+
+    /**
+     * Parses and verifies an Event instance from the HTTP request and
+     * fires it off to the registered listeners.
+     *
+     * @param request the HttpServletRequest to read the Event instance from
+     * @return the Event instance that was read from the request body, null if the request
+     * not contain a webhook event
+     * @throws GitLabApiException if the parsed event is not supported
+     */
+    public Event handleRequest(HttpServletRequest request) throws GitLabApiException {
 
         String eventName = request.getHeader("X-Gitlab-Event");
         if (eventName == null || eventName.trim().isEmpty()) {
             LOGGER.warning("X-Gitlab-Event header is missing!");
-            return;
+            return (null);
         }
 
         if (!isValidSecretToken(request)) {
@@ -101,6 +133,7 @@ public class WebHookManager extends HookManager {
             event.setRequestUrl(request.getRequestURL().toString());
             event.setRequestQueryString(request.getQueryString());
             fireEvent(event);
+            return (event);
 
         } catch (Exception e) {
             LOGGER.warning("Error parsing JSON data, exception=" + e.getClass().getSimpleName() + ", error=" + e.getMessage());