Yes - obviously up to the circuit limits.
Without going through the datasheet I'll give you some theoretical values. Lets assume the dropout of the LM317 is 3 volts (it may be different)
With an input voltage of 30V, the output voltage will be 27 volts maximum.
Now set the current to 10mA with the external resistors, put a 1 ohm load on it, it will limit the current to 10mA
Put a 10 ohm load on it, it will still limit the current to 10mA
Put a 1000 ohm load on it, still 10mA limit
Put a 10000 ohm load on it, you'll now only have 2.7mA going through (27 volts into 10,000 ohms)
You may also want to heatsink the LM317 dependant on the input/output voltages and current required.