IBM WebSphere MQ retrieving messages

IBM WebSphere MQ Retrieve messages

Retrieve messages

To retrieve messages , Do the following ：

1. according to “ Create connection objects ” Create a connection object as described in . under these circumstances , Please create %Net.MQRecv Example .Connection Object has a message queue , You can retrieve messages from .
2. Call the following methods as needed ：

• %Get()- Return a string message by reference as the first parameter .
• %GetStream()- Given the initialized file character stream , This method retrieves messages from the queue , And put it into the file associated with the stream . Please note that , The... Of the stream must be set Filename Property to initialize it . Binary streams are not supported .

1. Check the value returned by the called method . see also “ Get the error code ”. please remember , When the queue is empty ,IBM WebSphere MQ return 2033.
2. After retrieving the message , call Connection Object's %Close() Method to release the handle of the dynamic link library .

Example 1：ReceiveString()

The following class methods are from mqtest Queue retrieval messages .

///Method returns string or null or error message
ClassMethod ReceiveString() As %String
{
 Set recv=##class(%Net.MQRecv).%New()
 Set queue="mqtest"
 Set qm="QM_antigua"
 Set chan="S_antigua/TCP/antigua(1414)"
 Set logfile="c:\mq-recv-log.txt"
 
 Set check=recv.%Init(queue,qm,chan,logfile)
 If 'check  Quit recv.%GetLastError()

 Set check=recv.%Get(.msg)
 If 'check {
     Set reasoncode=recv.%GetLastError()
     If reasoncode=2033 Quit ""
     Quit "ERROR: "_reasoncode
     }
 
 Quit msg
}

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Example 2：ReceiveCharacterStream()

The following methods can retrieve longer messages , Because it uses %GetStream()：

/// Method returns reason code from IBM WebSphere MQ
ClassMethod ReceiveCharacterStream() As %Integer
{
 Set recv=##class(%Net.MQRecv).%New()
 Set queue="mqtest"
 Set qm="QM_antigua"
 Set chan="S_antigua/TCP/antigua(1414)"
 Set logfile="c:\mq-recv-log.txt"

 Set check=recv.%Init(queue,qm,chan,logfile)
 If 'check  Quit recv.%GetLastError()
 
 //initialize the stream and tell it what file to use
 //make sure filename is unique we can tell what we received
 Set longmsg=##class(%FileCharacterStream).%New()
 Set longmsg.Filename="c:\mq-received"_$h_".txt"

 Set check=recv.%GetStream(longmsg)

 If 'check  Quit recv.%GetLastError()
 Quit check
}

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Update message information

%Net.MQSend and %Net.MQRecv Class also provides the following methods ：

%CorId()

( By quoting ) Update the association of the last read message ID.

%ReplyQMgrName()

( By quoting ) Update the reply queue manager name of the last read message .

%ReplyQName()

( By quoting ) Update the reply queue name of the last read message .

Troubleshooting

If you are using IBM WebSphere MQ Of InterSystems IRIS Interface encountered a problem , You should first determine whether the client is installed correctly and can communicate with the server . To perform such a test , have access to IBM WebSphere MQ Sample program provided . The executable is located at IBM WebSphere MQ Client's bin Directory .

The following steps describe how to Windows Use these sample programs on . On other operating systems , The details may vary ; Please refer to IBM Document and check the name of the file that exists in your client .

1. Create a file called MQSERVER Environment variables of . The format of its value should be channel_name/Transport/server, among channel_name Is the name of the channel to be used ,Transport Is a string indicating the transfer to be used , and server Is the name of the server . for example ：S_Antigua/TCP/Antigua
2. On the command line , Enter the following command ：

amqsputc queue_name queue_manager_name

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among ,QUEUE_NAME Is the name of the queue to be used ,QUEUE_MANAGER_NAME Is the name of the queue manager . for example ：

amqsputc mqtest QM_antigua

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If amqsputc The command does not recognize , Please make sure it is updated PATH Environment variables to include IBM WebSphere MQ Client's bin Catalog .

1. You should see a few lines of code , As shown below ：

Sample AMQSPUT0 start
target queue is mqtest

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1. Now you can send messages . Just type in each message , Then press... After each message Enter Press the key . for example ：

sample message 1
sample message 2

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1. After sending the email , Press two times. Enter key . then , You will see the line shown below ：

Sample AMQSPUT0 end

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1. To complete this test , We will retrieve the messages sent to the queue . Type the following command on the command line ：

amqsgetc queue_name queue_manager_name

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among ,QUEUE_NAME Is the name of the queue to be used ,QUEUE_MANAGER_NAME Is the name of the queue manager . for example ：

1. then , You should see a starting line , Followed by the message sent before , As shown below ：

Sample AMQSGET0 start
message <sample message 1>
message <sample message 2>

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1. This sample program briefly waits to receive any other messages , Then display the following ：

no more messages
Sample AMQSGET0 end

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If the test fails , Please refer to IBM file . The possible causes of the problem include the following aspects ：

• safety problem
• The queue definition is incorrect
• The queue manager did not start