The IBM MQ classes for Java configuration file

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

The format of an IBM MQ classes for Java configuration file is that of a standard Java properties file.

From IBM MQ 8.0.0, Fix Pack 7, a sample configuration file, mqjava.config, is supplied in the bin subdirectory of the IBM MQ classes for Java installation directory. This file documents all the supported properties and their default values.

Note: The sample configuration file is overwritten when the IBM MQ installation is upgraded to a future Fix Pack. Therefore, it is recommended that you make a copy of the sample configuration file for use with your applications.

You can choose the name and location of an IBM MQ classes for Java 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 Java configuration file. URLs of the following types are supported: http, file, ftp, and jar.

The following example shows a java command:


java -Dcom.ibm.msg.client.config.location=file:/D:/mydir/mqjava.config MyAppClass

This command identifies the IBM MQ classes for Java configuration file as the file D:\mydir\mqjava.config on the local Windows system.

When an application starts, IBM MQ classes for Java 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 Java uses the default values for all the properties. If required, you can override any property in the configuration file by specifying it as a system property on the java command.

An IBM MQ classes for Java 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 Java. However, properties that are 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 an IBM MQ MQI client configuration file by specifying it as a property in an IBM MQ classes for Java configuration file. To override an attribute in an IBM MQ MQI client configuration file, use an entry with the following format in the IBM MQ classes for Java 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 that is 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 Java. If you specify or override other attributes, it has no effect. Specifically, 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 Java for details of how to use the CCDT with the IBM MQ classes for Java.

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	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 more information on the IBM MQ MQI client configuration, see Configuring a client using a configuration file.