Check out the Processing Serial library:
You should be able to create a simple protocol for the sensor data, write the data from Arduino over the Serial port, read it in Processing and trigger the right behavior.
You could try something like this, for example:
A12
B123
A10
C1234
where the first letter of each line is the name of the sensor, and the number that follows gives the value of the sensor. You can use the Processing function readStringUntil() (readStringUntil() / Libraries / Processing.org) to read a line at a time.