feat(demos): add seperately demos
diff --git a/demos/orderly_push_consumer.go b/demos/orderly_push_consumer.go
new file mode 100644
index 0000000..bf10055
--- /dev/null
+++ b/demos/orderly_push_consumer.go
@@ -0,0 +1,82 @@
+/*
+ * 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.
+ */
+
+package main
+
+import (
+	"fmt"
+	"github.com/apache/rocketmq-client-go/core"
+	"math/rand"
+	"sync/atomic"
+)
+
+func main() {
+	pConfig := &rocketmq.PushConsumerConfig{
+		ClientConfig: rocketmq.ClientConfig{
+			GroupID:    "GID_XXXXXXXXXXXX",
+			NameServer: "http://XXXXXXXXXXXXXXXXXX:80",
+			Credentials: &rocketmq.SessionCredentials{
+				AccessKey: "Your Access Key",
+				SecretKey: "Your Secret Key",
+				Channel:   "ALIYUN/OtherChannel",
+			},
+		},
+		Model:         rocketmq.Clustering,
+		ConsumerModel: rocketmq.Orderly,
+	}
+	ConsumeWithOrderly(pConfig)
+}
+func ConsumeWithOrderly(config *rocketmq.PushConsumerConfig) {
+
+	consumer, err := rocketmq.NewPushConsumer(config)
+	if err != nil {
+		println("create Consumer failed, error:", err)
+		return
+	}
+
+	ch := make(chan interface{})
+	var count = (int64)(1000000)
+	// ********************************************
+	// MUST subscribe topic before consumer started.
+	// *********************************************
+	consumer.Subscribe("YourOrderlyTopicXXXXXXXX", "*", func(msg *rocketmq.MessageExt) rocketmq.ConsumeStatus {
+		fmt.Printf("A message received, MessageID:%s, Body:%s \n", msg.MessageID, msg.Body)
+		if atomic.AddInt64(&count, -1) <= 0 {
+			ch <- "quit"
+		}
+		if 0 == rand.Int()%7 {
+			fmt.Printf("Consumer Later, MessageID:%s \n", msg.MessageID)
+			return rocketmq.ReConsumeLater
+		}
+		return rocketmq.ConsumeSuccess
+	})
+
+	err = consumer.Start()
+	if err != nil {
+		println("consumer start failed,", err)
+		return
+	}
+
+	fmt.Printf("consumer: %s started...\n", consumer)
+	<-ch
+	err = consumer.Shutdown()
+	if err != nil {
+		println("consumer shutdown failed")
+		return
+	}
+	println("consumer has shutdown.")
+}
diff --git a/demos/producer.go b/demos/producer.go
new file mode 100644
index 0000000..a941305
--- /dev/null
+++ b/demos/producer.go
@@ -0,0 +1,66 @@
+/*
+ * 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.
+ */
+
+package main
+
+import (
+	"fmt"
+	"github.com/apache/rocketmq-client-go/core"
+)
+
+func main() {
+	pConfig := &rocketmq.ProducerConfig{
+		ClientConfig: rocketmq.ClientConfig{
+			GroupID:    "GID_XXXXXXXXXXXX",
+			NameServer: "http://XXXXXXXXXXXXXXXXXX:80",
+			Credentials: &rocketmq.SessionCredentials{
+				AccessKey: "Your Access Key",
+				SecretKey: "Your Secret Key",
+				Channel:   "ALIYUN/OtherChannel",
+			},
+		},
+		//Set to Common Producer as default.
+		ProducerModel: rocketmq.CommonProducer,
+	}
+	sendMessage(pConfig)
+}
+func sendMessage(config *rocketmq.ProducerConfig) {
+	producer, err := rocketmq.NewProducer(config)
+
+	if err != nil {
+		fmt.Println("create common producer failed, error:", err)
+		return
+	}
+
+	err = producer.Start()
+	if err != nil {
+		fmt.Println("start common producer error", err)
+		return
+	}
+	defer producer.Shutdown()
+
+	fmt.Printf("Common producer: %s started... \n", producer)
+	for i := 0; i < 10; i++ {
+		msg := fmt.Sprintf("%s-%d", "Hello,Common MQ Message-", i)
+		result, err := producer.SendMessageSync(&rocketmq.Message{Topic: "YourTopicXXXXXXXX", Body: msg})
+		if err != nil {
+			fmt.Println("Error:", err)
+		}
+		fmt.Printf("send message: %s result: %s\n", msg, result)
+	}
+	fmt.Println("shutdown common producer.")
+}
diff --git a/demos/producer_orderly.go b/demos/producer_orderly.go
new file mode 100644
index 0000000..7822448
--- /dev/null
+++ b/demos/producer_orderly.go
@@ -0,0 +1,60 @@
+/*
+ * 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.
+ */
+package main
+
+import (
+	"fmt"
+	"github.com/apache/rocketmq-client-go/core"
+	"time"
+)
+
+func main() {
+	pConfig := &rocketmq.ProducerConfig{
+		ClientConfig: rocketmq.ClientConfig{
+			GroupID:    "GID_XXXXXXXXXXXX",
+			NameServer: "http://XXXXXXXXXXXXXXXXXX:80",
+			Credentials: &rocketmq.SessionCredentials{
+				AccessKey: "Your Access Key",
+				SecretKey: "Your Secret Key",
+				Channel:   "ALIYUN/OtherChannel",
+			},
+		},
+		ProducerModel: rocketmq.OrderlyProducer,
+	}
+	sendMessageOrderlyByShardingKey(pConfig)
+}
+func sendMessageOrderlyByShardingKey(config *rocketmq.ProducerConfig) {
+	producer, err := rocketmq.NewProducer(config)
+	if err != nil {
+		fmt.Println("create Producer failed, error:", err)
+		return
+	}
+
+	producer.Start()
+	defer producer.Shutdown()
+	for i := 0; i < 1000; i++ {
+		msg := fmt.Sprintf("%s-%d", "Hello Lite Orderly Message", i)
+		r, err := producer.SendMessageOrderlyByShardingKey(
+			&rocketmq.Message{Topic: "YourOrderLyTopicXXXXXXXX", Body: msg}, "ShardingKey" /*orderID*/)
+		if err != nil {
+			println("Send Orderly Message Error:", err)
+		}
+		fmt.Printf("send orderly message result:%+v\n", r)
+		time.Sleep(time.Duration(1) * time.Second)
+	}
+
+}
diff --git a/demos/push_consumer.go b/demos/push_consumer.go
new file mode 100644
index 0000000..af8a9a0
--- /dev/null
+++ b/demos/push_consumer.go
@@ -0,0 +1,77 @@
+/*
+ * 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.
+ */
+
+package main
+
+import (
+	"fmt"
+	"github.com/apache/rocketmq-client-go/core"
+	"sync/atomic"
+)
+
+func main() {
+	pConfig := &rocketmq.PushConsumerConfig{
+		ClientConfig: rocketmq.ClientConfig{
+			GroupID:    "GID_XXXXXXXXXXXX",
+			NameServer: "http://XXXXXXXXXXXXXXXXXX:80",
+			Credentials: &rocketmq.SessionCredentials{
+				AccessKey: "Your Access Key",
+				SecretKey: "Your Secret Key",
+				Channel:   "ALIYUN/OtherChannel",
+			},
+		},
+		Model:         rocketmq.Clustering,
+		ConsumerModel: rocketmq.CoCurrently,
+	}
+	ConsumeWithPush(pConfig)
+}
+func ConsumeWithPush(config *rocketmq.PushConsumerConfig) {
+
+	consumer, err := rocketmq.NewPushConsumer(config)
+	if err != nil {
+		println("create Consumer failed, error:", err)
+		return
+	}
+
+	ch := make(chan interface{})
+	var count = (int64)(1000000)
+	// ********************************************
+	// MUST subscribe topic before consumer started.
+	// *********************************************
+	consumer.Subscribe("YourTopicXXXXXXXX", "*", func(msg *rocketmq.MessageExt) rocketmq.ConsumeStatus {
+		fmt.Printf("A message received, MessageID:%s, Body:%s \n", msg.MessageID, msg.Body)
+		if atomic.AddInt64(&count, -1) <= 0 {
+			ch <- "quit"
+		}
+		return rocketmq.ConsumeSuccess
+	})
+
+	err = consumer.Start()
+	if err != nil {
+		println("consumer start failed,", err)
+		return
+	}
+
+	fmt.Printf("consumer: %s started...\n", consumer)
+	<-ch
+	err = consumer.Shutdown()
+	if err != nil {
+		println("consumer shutdown failed")
+		return
+	}
+	println("consumer has shutdown.")
+}