Use transactions to process messages in MSMQ

The following example uses MSMQ to send and receive objects of the person and Order Types and uses transaction ).

 

1. First define the person class and order class:

 

// Personnel class <br/> public class person <br/> {<br/> Public Person () <br/> {<br/> m_name = ""; <br/> m_age = 0; <br/>}</P> <p> Public Person (string name, uint16 age) <br/>{< br/> m_name = Name; <br/> m_age = age; <br/>}</P> <p> // name <br/> Public string name <br/>{< br/> get {return m_name ;} <br/> set {m_name = value ;} <br/>}</P> <p> // age <br/> Public uint16 age <br/>{< br/> get {return m_age ;} <br/> set {m_age = value ;}< br/>}</P> <p> private string m_name; <br/> private uint16 m_age; <br/>}< br/>

 

// Shopping list <br/> public class order <br/> {<br/> Public Order () <br/> {<br/> price = 0.0; <br/> Number = 0; <br/> time = datetime. now; <br/>}</P> <p> Public Order (double price, uint64 number, datetime time) <br/>{< br/> price = price; <br/> Number = number; <br/> time = time; <br/>}</P> <p> // item unit price <br/> double price; </P> <p> // item quantity <br/> uint64 number; </P> <p> // order time <br/> datetime time; <br/>}

 

2. The following functions are used to create a message queue:

 

// Function for creating a Message Queue <br/> static void createmessagequeue () <br/>{< br/> string mqname = @". /private $/testmq "; </P> <p> // if the message queue already exists, it is not created <br/> If (! Messagequeue. exists (mqname) <br/>{< br/> messagequeue. Create (mqname, true); <br/>}< br/>}

 

3. The function for sending and receiving messages is defined below:

 

// Message sending function <br/> static bool send (person, order, string description) <br/>{< br/> messagequeue MQ = new messagequeue (@". /private $/testmq "); </P> <p> // specify that the message is encoded in XML format <br/> MQ. formatter = new xmlmessageformatter (New Type [] {typeof (person), typeof (Order), typeof (string )}); </P> <p> // define the transaction <br/> messagequeuetransaction transaction = new messagequeuetransaction (); </P> <p> try <br/> {<br/> // if the message queue uses a transaction, start the transaction <br/> If (MQ. transactional) <br/> transaction. begin (); </P> <p> message msg1 = new message (person); <br/> MQ. send (msg1, transaction); </P> <p> message msg2 = new message (order); <br/> MQ. send (msg2, transaction); </P> <p> message msg3 = new message (description); <br/> MQ. send (msg3, transaction); </P> <p> // If a Message Queue uses a transaction, stop the transaction. <br/> If (MQ. transactional) <br/> transaction. commit (); </P> <p> return true; <br/>}< br/> catch (exception ex) <br/>{< br/> // if the message queue adopts a transaction and an exception occurs, terminate the transaction. <br/> If (MQ. transactional) <br/> transaction. abort (); </P> <p> return false; <br/>}< br/>}

 

// Function for receiving messages <br/> static object [] receive () <br/>{< br/> messagequeue MQ = new messagequeue (@". /private $/testmq "); </P> <p> // defines all types of messages in the Message Queue (the order between types can be exchanged) <br/> type [] msgtypes = new type [] {typeof (person), typeof (Order), typeof (string )}; </P> <p> // specify that the message is encoded in XML format <br/> MQ. formatter = new xmlmessageformatter (msgtypes); </P> <p> // defines the transaction <br/> messagequeuetransaction transaction = new messagequeuetransaction (); </P> <p> try <br/> {<br/> // if the message queue uses a transaction, start the transaction <br/> If (MQ. transactional) <br/> transaction. begin (); </P> <p> message msg1 = MQ. receive (transaction); <br/> person = (person) msg1.body; </P> <p> message msg2 = MQ. receive (transaction); <br/> order = (Order) msg2.body; </P> <p> message msg3 = MQ. receive (transaction); <br/> string description = (string) msg3.body; </P> <p> // if the message queue uses transactions, stop the transaction <br/> If (MQ. transactional) <br/> transaction. commit (); </P> <p> return new object [] {person, order, description };< br/>}< br/> catch (exception ex) <br/>{< br/> // if the message queue adopts a transaction and an exception occurs, terminate the transaction. <br/> If (MQ. transactional) <br/> transaction. abort (); </P> <p> return NULL; <br/>}< br/>}

 

4. The following two main functions are used to send and receive messages respectively. (Generally, the sender and receiver of a message are not in the same process or in the same thread .)

 

// Main function of the message sender <br/> static void main (string [] ARGs) <br/>{< br/> // create a message queue <br/> createmessagequeue (); </P> <p> person = new person ("Jackie ", 30); <br/> order = New Order (110.0, 10, datetime. now); <br/> string description = "this is a new order. "; </P> <p> If (send (person, order, description) <br/>{< br/> console. writeline ("message sent successfully! "); <Br/>}< br/> else <br/>{< br/> console. writeline (" message sending failed! "); <Br/>}< br/>}

 

// Message Receiver main function <br/> static void main (string [] ARGs) <br/>{< br/> // create a message queue <br/> createmessagequeue (); </P> <p> // receives messages. If the returned value is null, the receiving fails. <br/> object [] Message = receive (); </P> <p> If (message! = NULL) <br/>{< br/> // when the message is successfully received, the message is retrieved and saved to the following objects in sequence <br/> person = (person) message [0]; <br/> order prder = (Order) Message [1]; <br/> string description = (string) Message [2]; </P> <p> console. writeline ("Message received successfully! "); <Br/>}< br/> else <br/>{< br/> console. writeline (" message receipt failed! "); <Br/>}< br/>}