Code Generation

Since DBus provides a mechanism for introspecting objects via the org.freedesktop.DBus.Introspectable interface, it is possible to query an already running application for information about interfaces that it has. This will then return an XML file, which you can then run the code generator against in order to produce a Java interface that you can then use to get a remote object, or use as an interface for your program.

New code generation

You can directly obtain the required interface information by reading the introspection data directly from DBus:

mvn exec:java \
  -Dexec.mainClass="org.freedesktop.dbus.utils.generator.InterfaceCodeGenerator" \
  -Dexec.executable="java" \
  -Dexec.args="%classpath --system --outputDir /tmp/classes org.bluez /org/bluez"

You can also use introspection data which is stored in an xml file:

mvn exec:java \
  -Dexec.mainClass="org.freedesktop.dbus.utils.generator.InterfaceCodeGenerator" \
  -Dexec.executable="java" \
  -Dexec.args="%classpath --inputFile /tmp/org.freedesktop.UDisks2.xml --outputDir /tmp/classes ' '"

In both cases the generated classes/interfaces will be written to the provided output directory.

Old code generation

Obtain the introspection XML file from the service that you wish to use or implement. These introspection XML files are often in the source code of the reference application. If the application is running on DBus, you can obtain the introspection XML using a dbus-send query such as the following (change the ‘dest’ and path as appropriate):
```
dbus-send --print-reply=literal --type=method_call --dest=org.freedesktop.Notifications /org/freedesktop/Notifications org.freedesktop.DBus.Introspectable.Introspect
```

Run the code generator on the given XML file.

org.freedesktop.dbus.utils.bin.CreateInterface /path/to/introspection.xml

The code will be printed to stdout; copy and paste it into a file.