Following code.
//OBJETO FUZZY
Engine engine = new Engine();
engine.setName("simple-dimmer");
//VARIAVEIS LINGUISTICAS DE ENTRADA
InputVariable inputVariable = new InputVariable();
inputVariable.setEnabled(true);
inputVariable.setName("Ambient");
inputVariable.setRange(0.000, 1.000);
inputVariable.addTerm(new Triangle("DARK", 0.000, 0.250, 0.500));
inputVariable.addTerm(new Triangle("MEDIUM", 0.250, 0.500, 0.750));
inputVariable.addTerm(new Triangle("BRIGHT", 0.500, 0.750, 1.000));
engine.addInputVariable(inputVariable);
//SAIDA
OutputVariable outputVariable = new OutputVariable();
outputVariable.setEnabled(true);
outputVariable.setName("Power");
outputVariable.setRange(0.000, 1.000);
outputVariable.fuzzyOutput().setAccumulation(new Maximum());
outputVariable.fuzzyOutput().setAccumulation(new AlgebraicSum());
outputVariable.setDefuzzifier(new WeightedAverage());
outputVariable.setDefuzzifier(new Centroid(200));
outputVariable.setDefaultValue(Double.NaN);
outputVariable.setLockValidOutput(false);
outputVariable.setLockOutputRange(false);
outputVariable.addTerm(new Constant("LOW", 0.250));
outputVariable.addTerm(new Constant("MEDIUM", 0.500));
outputVariable.addTerm(new Constant("HIGH", 0.750));
engine.addOutputVariable(outputVariable);
//RULES
RuleBlock ruleBlock = new RuleBlock();
ruleBlock.setEnabled(true);
ruleBlock.setName("");
ruleBlock.setConjunction(new Minimum());
ruleBlock.setDisjunction(new Maximum());
ruleBlock.setActivation(new Minimum());
ruleBlock.addRule(Rule.parse("if Ambient is DARK then Power is HIGH",engine));
ruleBlock.addRule(Rule.parse("if Ambient is MEDIUM then Power is MEDIUM", engine));
ruleBlock.addRule(Rule.parse("if Ambient is BRIGHT then Power is LOW",engine));
engine.addRuleBlock(ruleBlock);
StringBuilder status = new StringBuilder();
if (!engine.isReady(status))
throw new RuntimeException("Nao foi possivel gerar o arquivo. "
+ "O seguintes erros foram encontrados:\n"
+ status.toString());
engine.setInputValue("Ambient", 0.1);
engine.process();
System.out.println(engine.getOutputValue("Power"));