The IBM MQ classes for JMS configuration file

An IBM® MQ classes for JMS configuration file specifies properties that are used to configure IBM MQ classes for JMS.

Note: The properties defined in configuration file can also be set as JVM system properties. If a property is set both in the configuration file and as a system property, the system property takes precedence. Therefore, if required, you can override any property in the configuration file by specifying it as a system property on the java command.

The format of an IBM MQ classes for JMS configuration file is that of a standard Java properties file. A sample configuration file called jms.config is supplied in the bin subdirectory of the IBM MQ classes for JMS installation directory. This file documents all the supported properties and their default values.

You can choose the name and location of a IBM MQ classes for JMS configuration file. When you start your application, use a java command with the following format: 

java -Dcom.ibm.msg.client.config.location= config_file_url application_name
In the command, config_file_url is a uniform resource locator (URL) that specifies the name and location of the IBM MQ classes for JMS configuration file. URLs of the following types are supported: http, file, ftp, and jar.
Here is an example of a java command: 

java -Dcom.ibm.msg.client.config.location=file:/D:/mydir/myjms.config MyAppClass
This command identifies the IBM MQ classes for JMS configuration file as the file D:\mydir\mjms.config on the local Windows system.

When an application starts, IBM MQ classes for JMS reads the contents of the configuration file and stores the specified properties in an internal property store. If the java command does not identify a configuration file, or if the configuration file cannot be found, IBM MQ classes for JMS uses the default values for all the properties.

An IBM MQ classes for JMS configuration file can be used with any of the supported transports between an application and a queue manager or broker.

Overriding properties specified in an IBM MQ MQI client configuration file

An IBM MQ MQI client configuration file can also specify properties that are used to configure IBM MQ classes for JMS. However, properties specified in an IBM MQ MQI client configuration file apply only when an application connects to a queue manager in client mode.

If required, you can override any attribute in a IBM MQ MQI client configuration file by specifying it as a property in a IBM MQ classes for JMS configuration file. To override an attribute in a IBM MQ MQI client configuration file, use an entry with the following format in the IBM MQ classes for JMS configuration file: 

com.ibm.mq.cfg. stanza. propName = propValue
The variables in the entry have the following meanings:
stanza
The name of the stanza in the IBM MQ MQI client configuration file that contains the attribute
propName
The name of the attribute as specified in the IBM MQ MQI client configuration file
propValue
The value of the property that overrides the value of the attribute specified in the IBM MQ MQI client configuration file

Alternatively, you can override an attribute in an IBM MQ MQI client configuration file by specifying the property as a system property on the java command. Use the preceding format to specify the property as a system property.

Only the following attributes in an IBM MQ MQI client configuration file are relevant to IBM MQ classes for JMS. If you specify or override other attributes, it has no effect. Specifically, please note that the ChannelDefinitionFile and ChannelDefinitionDirectory in the CHANNELS stanza of the client configuration file are not used. See Using a client channel definition table with IBM MQ classes for JMS for details of how to use the CCDT with the IBM MQ classes for JMS.
Table 1. Which stanza of the client configuration file contains which attribute.
Stanza Attribute
CHANNELS stanza of the client configuration file Put1DefaultAlwaysSync
CHANNELS stanza of the client configuration file DefRecon
CHANNELS stanza of the client configuration file ReconDelay
CHANNELS stanza of the client configuration file PasswordProtection
ClientExitPath stanza of the client configuration file ExitsDefaultPath
ClientExitPath stanza of the client configuration file ExitsDefaultPath64
ClientExitPath stanza of the client configuration file JavaExitsClasspath
JMQI stanza of the client configuration file useMQCSPauthentication
MessageBuffer stanza of the client configuration file MaximumSize
MessageBuffer stanza of the client configuration file PurgeTime
MessageBuffer stanza of the client configuration file UpdatePercentage
TCP stanza of the client configuration file ClntRcvBufSize
TCP stanza of the client configuration file ClntSndBufSize
TCP stanza of the client configuration file Connect_Timeout
TCP stanza of the client configuration file KeepAlive
For further details on the IBM MQ MQI client configuration see Configuring a client using a configuration file