This is a simple java code used to load a fuzzy inference system (FIS), this code available at net.sourceforge.jFuzzyLogic.TestTipper.java

First load an FCL file, using FIS.load(fileName) function.

String fileName = "fcl/tipper.fcl";
FIS fis = FIS.load(fileName,true);

When an error is detected during FIS.load(), a null object is returned.

if( fis == null ) { // Error while loading?
	System.err.println("Can't load file: '" + fileName + "'");
	return;
}

Now we can plot the FIS. Actually, we plot each Variable in the FUNCTION_BLOCK (and each LinguisticTerm in each Variable). This might only be usefull when you are debugging your code.
fis.chart();
And we get the following images:

Now we use the FIS. We start by setting FIS' inputs

fis.setVariable("service", 3);
fis.setVariable("food", 7);

And we run the system
fis.evaluate();
If we want to know the system's output (in this case there's only one output variable 'tip')
fis.getVariable("tip").getLatestDefuzzifiedValue();
We can also plot output's defuzzifier (probably only during debuging)
fis.getVariable("tip").chartDefuzzifier(true);
And, of course, we can print the FIS
System.out.println(fis);