[ISSUE #889] Python Example: start a simple consumer in background th…

…read (#889)

python/example/background_simple_consumer_example.py

@@ -0,0 +1,54 @@
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements.  See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership.
+# The ASF licenses this file to You under the Apache License, Version 2.0
+# (the "License"); you may not use this file except in compliance with
+# the License.  You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+from rocketmq import ClientConfiguration, Credentials, SimpleConsumer
+import asyncio
+import threading
+
+
+def start_simple_consumer():
+    endpoints = "endpoints"
+    credentials = Credentials("ak", "sk")
+    config = ClientConfiguration(endpoints, credentials)
+    topic = "topic"
+    try:
+        simple_consumer = SimpleConsumer(config, "consumer-group")
+        simple_consumer.startup()
+        simple_consumer.subscribe(topic)
+        while True:
+            try:
+                messages = simple_consumer.receive(32, 15)
+                if messages is not None:
+                    print(f"{simple_consumer.__str__()} receive {len(messages)} messages.")
+                    for msg in messages:
+                        simple_consumer.ack(msg)
+                        print(f"{simple_consumer.__str__()} ack message:[{msg.message_id}].")
+            except Exception as e:
+                print(f"receive or ack message raise exception: {e}")
+    except Exception as e:
+        print(f"simple consumer example raise exception: {e}")
+
+
+def run_simple_consumer():
+    loop = asyncio.new_event_loop()
+    asyncio.set_event_loop(loop)
+    loop.run_until_complete(start_simple_consumer())
+
+
+if __name__ == '__main__':
+    # start a simple consumer in background thread
+    t = threading.Thread(target=run_simple_consumer)
+    t.start()
+    print("start background simple consumer success!")
+    t.join()