Project: Apache RocketMQ (App Definition and Development / Streaming & Messaging)
File: API_Reference_DefaultMQProducer.md

`public class DefaultMQProducer extends ClientConfig implements MQProducer` `DefaultMQProducer` is the entry point for an application to post messages, out of the box, ca quickly create a producer with a no-argument construction. it is mainly responsible for message sending, support synchronousasynchronousone-way send. All of these send methods support batch send. The parameters of the sender can be adjusted through the getter/setter methods , provided by this class. `DefaultMQProducer` has multi send method and each method is slightly different. Make sure you know the usage before you use it . Blow is a producer example . . ``` java public class Producer { public static void main(String[] args) throws MQClientException { // create a produce with producergroupname DefaultMQProducer producer = new DefaultMQProducer("ProducerGroupName"); // start the producer producer.start(); for (int i = 0; i < 128; i++) try { // construct the msg Message msg = new Message("TopicTest", "TagA", "OrderID188", "Hello world".getBytes(RemotingHelper.DEFAULT_CHARSET)); // send sync SendResult sendResult = producer.send(msg); // print the result System.out.printf("%s%n", sendResult); } catch (Exception e) { e.printStackTrace(); } producer.shutdown(); } } ``` Note : This class is thread safe. It can be safely shared between multiple threads after configuration and startup is complete. |Type|Name| description | ||-|-| |DefaultMQProducerImpl|defaultMQProducerImpl|The producer's internal default implementation| |String|producerGroup|The producer's group| |String|createTopicKey| Topics that do not exist on the server are automatically created when the message is sent | |int|defaultTopicQueueNums|The default number of queues to create a topic| |int|sendMsgTimeout|The timeout for the message to be sent| |int|compressMsgBodyOverHowmuch|the threshold of the compress of message body| |int|retryTimesWhenSendFailed|Maximum number of internal attempts to send a message in synchronous mode| |int|retryTimesWhenSendAsyncFailed|Maximum number of internal attempts to send a message in asynchronous mode| |boolean|retryAnotherBrokerWhenNotStoreOK|Whether to retry another broker if an internal send fails| |int|maxMessageSize| Maximum length of message body | |TraceDispatcher|traceDispatcher| Message trackers. Use rcpHook to track messages | |Method name|Method description| |-|| |DefaultMQProducer()| creates a producer with default parameter values | |DefaultMQProducer(final String producerGroup)| creates a producer with producer group name. | |DefaultMQProducer(final String producerGroup, boolean enableMsgTrace)|creates a producer with producer group name and set whether to enable message tracking| |DefaultMQProducer(final String producerGroup, boolean enableMsgTrace, final String customizedTraceTopic)|creates a producer with producer group name and set whether to enable message trackingthe trace topic.| |DefaultMQProducer(RPCHook rpcHook)|creates a producer with a rpc hook.| |DefaultMQProducer(final String producerGroup, RPCHook rpcHook)|creates a producer with a rpc hook and producer group.| |DefaultMQProducer(final String producerGroup, RPCHook rpcHook, boolean enableMsgTrace,final String customizedTraceTopic)|all of above.|