When RPG starts the Java™ Virtual
Machine (JVM), there are several options that control how the JVM
is started. See the
Java System
Properties section in the
IBM® i
Information Center.
- You can place these options in the SystemDefault.properties file.
- You can use the CLASSPATH environment variable to specify the
classpath (see above).
- You can place these options in an environment variable called
QIBM_RPG_JAVA_PROPERTIES. Any options placed in this environment variable
will override the options in the SystemDefault.properties file.
If you specify the java.class.path option in this environment variable,
and you also specified the CLASSPATH environment variable, it is undefined
which value will take precedence for the classpath.
To specify
options in the QIBM_RPG_JAVA_PROPERTIES environment variable, you
code the options in a string, one after the other, separated by any
character that does not appear in any of the options. Then you end
the string with the separator character. For example, if you want
to specify the options
java.version=1.4
os400.stderr=file:stderr.txt
then you would add the environment variable using the
following command:
ADDENVVAR ENVVAR(QIBM_RPG_JAVA_PROPERTIES)
VALUE('-Djava.version=1.4;-Dos400.stderr=file:stderr.txt;')
If the options string is not valid, Java may
reject one of the options. Message JVAB55A will appear in the joblog
indicating which option was not valid. If this happens, RPG will try
to start the JVM again without any of the options, but still including
the java.class.path option if it came from the CLASSPATH environment
variable.
Some parameters and return values require conversion
between the job CCSID and the CCSID that Java uses
for byte arrays. The file.encoding Java property
is used by RPG to obtain the CCSID that Java uses.
Ensure that the file.encoding property is set correctly for your job
CCSID. You can allow Java to
set the property implicitly using attributes of your job, or you can
set the property explicitly using one of the mechanisms above. For
example, you could add '-Dfile.encoding=ISO8859_1' or '-Dfile.encoding=Cp948'
to your QIBM_RPG_JAVA_PROPERTIES environment variable. For more information
about the file.encoding property, see the IBM Developer
Kit for Java topic in the Information Center.
For more information about the properties you can
specify to control the Java virtual
machine, and other environment variables that may be required for Java to operate correctly, such
as the QIBM_USE_DESCRIPTOR_STDIO environment variable, see the see
the IBM Developer
Kit for Java topic
in the Information Center.
You may also need to consult the documentation for the specific Java classes that you will be using. 