Specifies a system property. A system property defines a common value for a setting at one of these levels, from highest to lowest: domain, server, or config. A value set at a higher level can be overridden at a lower level. Some system properties are predefined; see system-property. You can also create system properties using this element.
The following example shows the use of a predefined system property:
<log-service file="${com.sun.aas.instanceRoot}/logs/server.log">
    <module-log-levels admin=INFO .../>
</log-service>
The following example shows the creation and use of a system property:
<config name="config1">
    ...
    <http-service>
        ...
        <http-listener id="ls1" host="0.0.0.0" port="${ls1-port}"/>
        ...
    </http-service>
    ...
    <system-property name="ls1-port" value="8080"/>
</config>
The following table describes subelements for the system-property element.
Table 1–122 system-property Subelements| Element | Required | Description | 
|---|---|---|
| zero or one | Contains a text description of this element. | 
The following table describes attributes for the system-property element.
Table 1–123 system-property Attributes| Attribute | Default | Description | 
|---|---|---|
| none | Specifies the name of the system property. | |
| none | Specifies the value of the system property. | 
The following table lists predefined system properties.
Table 1–124 Predefined System Properties| Property | Default | Description | 
|---|---|---|
| com.sun.aas.installRoot | depends on operating system | Specifies the directory where the Application Server is installed. | 
| com.sun.aas.instanceRoot | depends on operating system | Specifies the top level directory for a server instance. | 
| com.sun.aas.hostName | none | Specifies the name of the host (machine). | 
| com.sun.aas.javaRoot | depends on operating system | Specifies the J2SE installation directory. | 
| com.sun.aas.imqLib | depends on operating system | Specifies the library directory for Sun Java System Message Queue. | 
| com.sun.aas.configName | server-config | Specifies the name of the config used by a server instance. | 
| com.sun.aas.instanceName | server1 | Specifies the name of the server instance. This property is not used in the default configuration, but can be used to customize configuration. | 
| com.sun.aas.domainName | domain1 | Specifies the name of the domain. This property is not used in the default configuration, but can be used to customize configuration. |