feat: add getContextId()/getTaskId() to the events-related interfaces

Signed-off-by: Jeff Mesnil <[email protected]>

Author: jmesnil

server-common/src/main/java/io/a2a/server/tasks/TaskManager.java

@@ -4,11 +4,13 @@
 
 import io.a2a.spec.A2AServerException;
 import io.a2a.spec.Event;
+import io.a2a.spec.EventKind;
 import io.a2a.spec.InvalidParamsError;
 import io.a2a.spec.Message;
+import io.a2a.spec.StreamingEventKind;
 import io.a2a.spec.Task;
-import io.a2a.spec.TaskArtifactUpdateEvent;
-import io.a2a.spec.TaskStatusUpdateEvent;
+import io.a2a.spec.UpdateEvent;
+
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -105,10 +107,8 @@ public Task processAndSave(Event event) throws A2AServerException {
     private String extractTaskId(Event event) {
         if (event instanceof Task task) {
             return task.getId();
-        } else if (event instanceof TaskStatusUpdateEvent taskStatusUpdateEvent) {
-            return taskStatusUpdateEvent.getTaskId();
-        } else if (event instanceof TaskArtifactUpdateEvent taskArtifactUpdateEvent) {
-            return taskArtifactUpdateEvent.getTaskId();
+        } else if (event instanceof UpdateEvent update) {
+            return update.getTaskId();
         }
         return null;
     }
@@ -117,12 +117,10 @@ private String extractTaskId(Event event) {
      * Extracts the context ID from an event.
      */
     private String extractContextId(Event event) {
-        if (event instanceof Task task) {
-            return task.getContextId();
-        } else if (event instanceof TaskStatusUpdateEvent taskStatusUpdateEvent) {
-            return taskStatusUpdateEvent.getContextId();
-        } else if (event instanceof TaskArtifactUpdateEvent taskArtifactUpdateEvent) {
-            return taskArtifactUpdateEvent.getContextId();
+        if (event instanceof EventKind kind) {
+            return kind.getContextId();
+        } else if (event instanceof StreamingEventKind kind) {
+            return kind.getContextId();
         }
         return null;
     }

spec/src/main/java/io/a2a/spec/Event.java

@@ -19,6 +19,7 @@
  *   <li>{@link Message} - Message exchange</li>
  *   <li>{@link TaskStatusUpdateEvent} - Task status changes</li>
  *   <li>{@link TaskArtifactUpdateEvent} - Artifact creation/updates</li>
+ *   <li>{@link A2AError} - Error</li>
  * </ul>
  *
  * @see EventKind

spec/src/main/java/io/a2a/spec/EventKind.java

@@ -43,4 +43,6 @@ public interface EventKind {
      * @return the event kind string (e.g., "task", "message")
      */
     String getKind();
+
+    String getContextId();
 }

spec/src/main/java/io/a2a/spec/Message.java

@@ -96,6 +96,7 @@ public String getMessageId() {
         return messageId;
     }
 
+    @Override
     public String getContextId() {
         return contextId;
     }

spec/src/main/java/io/a2a/spec/StreamingEventKind.java

@@ -57,4 +57,6 @@ public sealed interface StreamingEventKind extends Event permits Task, Message,
      * @return the event kind string (e.g., "task", "message", "status-update", "artifact-update")
      */
     String getKind();
+
+    String getContextId();
 }

spec/src/main/java/io/a2a/spec/Task.java

@@ -88,6 +88,7 @@ public String getId() {
         return id;
     }
 
+    @Override
     public String getContextId() {
         return contextId;
     }

spec/src/main/java/io/a2a/spec/TaskArtifactUpdateEvent.java

@@ -80,6 +80,7 @@ public TaskArtifactUpdateEvent(@JsonProperty("taskId") String taskId, @JsonPrope
         this.kind = kind;
     }
 
+    @Override
     public String getTaskId() {
         return taskId;
     }
@@ -88,6 +89,7 @@ public Artifact getArtifact() {
         return artifact;
     }
 
+    @Override
     public String getContextId() {
         return contextId;
     }

spec/src/main/java/io/a2a/spec/TaskStatusUpdateEvent.java

@@ -53,6 +53,7 @@ public TaskStatusUpdateEvent(@JsonProperty("taskId") String taskId, @JsonPropert
         this.kind = kind;
     }
 
+    @Override
     public String getTaskId() {
         return taskId;
     }
@@ -61,6 +62,7 @@ public TaskStatus getStatus() {
         return status;
     }
 
+    @Override
     public String getContextId() {
         return contextId;
     }

spec/src/main/java/io/a2a/spec/UpdateEvent.java

@@ -21,4 +21,7 @@
  * @see TaskArtifactUpdateEvent
  */
 public sealed interface UpdateEvent permits TaskStatusUpdateEvent, TaskArtifactUpdateEvent {
+    String getContextId();
+
+    String getTaskId();
 }