Dedicated Java System Properties

The pre-compiled installer "understands" a couple of system properties given to the JVM at runtime.

At the command line, they can be given as -D<propertyname>=<value>.

The following property names and their according values are known to an IzPack installer at runtime:

NamePossible valuesDefaultDescription
INSTALL_PATHAny path according to the host OSbuilt-in
(OS-dependent) 

This allows to initialize the installation root path the user can change for example on a TargetPanel.

The value of this system property is directly mapped to the reserved IzPack variable $INSTALL_PATH.

MULTIINSTANCEtrue | falsefalse

There is a built-in feature of popping up a message which asks the user whether an already running instance of the same installer should be ignored or rather whether to abort. This can be inconvenient for some use cases (clustering, sub-calls when an installer calls itself with different options,...).

This option allows to disable this behavior at compile time. The value true means to override the default behavior and allow multiple instances of an installer. The default is multi-instance check at installer start (MULTIINSTANCE=false).

Since: IzPack 5.0 RC5

STACKTRACEtrue | falsefalseWhether to show Java stacktraces are on the installer's console output. This can be useful for debugging and reporting errors to installer or IzPack developers.
DEBUGtrue | falsefalseWhether to show particular runtime information on the installer's console output. This can be useful for debugging and reporting errors to installer or IzPack developers.
TRACEtrue | falsefalseWhether to show an extra panel on GUI installers only displaying the current values and change traces of the installer's internal variables and conditions. This can be useful for debugging and reporting errors to installer or IzPack developers.

Command line options

The installer does also take a number of command line options:

OptionPossible valuesDefaultDescription
-console--

Use console installation mode instead of GUI.

In headless environments, if the graphics environment cannot be initialized, this option is selected as fallback automatically.

-languageISO3 language code-

Using this option it is possible to preset the language the installation should run in.

This option overrides system settings and skips the language dialog, while propagating the selected language to the installer at runtime.

Since: 5.0.7

-mediaA valid absolute directory path.The directory where the installer jar itself is located.For multi volume installation, this is the directory where all parts of the installer are searched for assembly,
-defaults-file
A valid absolute file path.The file with the variable default overrides to be processed.

See Mixed Installation Mode Using Variable Defaults.

Since: 5.0.10

-auto--

In combination with -defaults-file, runs the installer in automated mode after loading the variable default overrides.

See Mixed Installation Mode Using Variable Defaults.

Since: 5.0.10

-options
-options-auto
-options-template
A valid path to a properties file.-See Unattended Installations Using Properties.
-options-system

-debug-(no debug mode)

Switching debug mode on. This option has no parameters.
In debug mode, there are many more log entries shown in the log which may be helpful for installer developers.
Same like -DDEBUG=true.

Since: 5.1.0

-trace-(no trace mode)

Switching trace mode on. This option has no parameters.
In trace mode, an embedded widget to the installer window is shown (just in GUI mode), seeing all conditions and variables settings and traces how their values changed during the actual session according to the user input.
Same like -DTRACE=true.

Since: 5.1.0 

-stacktrace-(no stacktrace mode)

Switching stacktrace mode on. This option has no parameters.
In stacktrace mode, if a Java exception is thrown in the code the stacktrace is logged, otherwise just the exception message is shown in the log.
Same like -DSTACKTRACE=true.

Since: 5.1.0