给定下面的矩阵，用Java实现该矩阵的一种好方法是什么？
我想返回字符串消息，例如"Possibly OK"在该位置满足相应谓词时，例如pIndex = 4, volume = 1。
我本质上具有5 * 5条件，因此有25个可能性。
这是我能想到的最好的方法（必须有一种更整洁，更易于维护的方法，如果if语句不是笨拙的）：
@Test
void decisionMakerTest() {
String decision = DecisionMaker.makeDecision(4.0, 1.0);
Assertions.assertEquals("Possibly OK", decision);
}
class DecisionMaker {
private DecisionMaker() {
throw new IllegalStateException("Utility class");
}
private static List<Rule> ruleList = new ArrayList<>(Arrays.asList(
new Rule(i -> (i <= 5), v -> (v <= -10), "Too Low"),
new Rule(i -> (i <= 5), v -> (-10 < v && v <= -5), "Too Low"),
new Rule(i -> (i <= 5), v -> (-5 < v && v < 2), "Possibly OK"),
new Rule(i -> (i <= 5), v -> (2 <= v && v < 5), "Possibly OK"),
new Rule(i -> (i <= 5), v -> (5 <= v), "Other - Investigate"),
new Rule(i -> (5 < i && i <= 10), v -> (v <= -10), "Too Low"),
new Rule(i -> (5 < i && i <= 10), v -> (-10 < v && v <= -5), "Possibly Too Low"),
new Rule(i -> (5 < i && i <= 10), v -> (-5 < v && v < 2), "OK"),
new Rule(i -> (5 < i && i <= 10), v -> (2 <= v && v < 5), "OK"),
new Rule(i -> (5 < i && i <= 10), v -> (5 <= v), "Possibly Too High"),
new Rule(i -> (10 < i && i < 90), v -> (v <= -10), "Possibly Too Low"),
new Rule(i -> (10 < i && i < 90), v -> (-10 < v && v <= -5), "OK"),
new Rule(i -> (10 < i && i < 90), v -> (-5 < v && v < 2), "OK"),
new Rule(i -> (10 < i && i < 90), v -> (2 <= v && v < 5), "OK"),
new Rule(i -> (10 < i && i < 90), v -> (5 <= v), "Possibly Too High"),
new Rule(i -> (90 <= i && i < 95), v -> (v <= -10), "Possibly Too Low"),
new Rule(i -> (90 <= i && i < 95), v -> (-10 < v && v <= -5), "OK"),
new Rule(i -> (90 <= i && i < 95), v -> (-5 < v && v < 2), "OK"),
new Rule(i -> (90 <= i && i < 95), v -> (2 <= v && v < 5), "Possibly Too High"),
new Rule(i -> (90 <= i && i < 95), v -> (5 <= v), "Too High"),
new Rule(i -> (95 <= i), v -> (v <= -10), "Other - Investigate"),
new Rule(i -> (95 <= i), v -> (-10 < v && v <= -5), "Possibly OK"),
new Rule(i -> (95 <= i), v -> (-5 < v && v < 2), "Possibly OK"),
new Rule(i -> (95 <= i), v -> (2 <= v && v < 5), "Too High"),
new Rule(i -> (95 <= i), v -> (5 <= v), "Too High")
));
static String makeDecision(double pIndex, double volume) {
for (Rule rule : ruleList) {
if (rule.test(pIndex, volume)) {
return rule.getDecision();
}
}
return "Other - Investigate";
}
}
class Rule {
private DoublePredicate pIndexRule;
private DoublePredicate volumeRule;
private String decision;
Rule(
DoublePredicate pIndexRule, DoublePredicate volumeRule, String decision
) {
this.pIndexRule = pIndexRule;
this.volumeRule = volumeRule;
this.decision = decision;
}
public boolean test(double pIndex, double volume) {
return pIndexRule.test(pIndex) && volumeRule.test(volume);
}
String getDecision() {
return decision;
}
}
最佳答案
您可以尝试如下操作：
class DecisionMaker {
static final List<DoublePredicate> P_INDEX_TEST = Arrays.asList(
x -> x > 5.0,
x -> x > 10.0,
x -> x >= 90.0,
x -> x >= 95.0
);
static final List<DoublePredicate> VOLUME_TEST = Arrays.asList(
x -> x > -10.0,
x -> x > -5.0,
x -> x >= 2.0,
x -> x >= 5.0
);
static final String[][] TABLE = {
{"Too Low", "Too Low", "Possibly OK", "Possibly OK", "Other - Investigate"},
{"Too Low", "Possibly Too Low", "OK", "OK", "Possibly Too High"},
{"Possibly Too Low", "OK", "OK", "OK", "Possibly Too High"},
{"Possibly Too Low", "OK", "OK", "Possibly Too High", "Too High"},
{"Other - Investigate", "Possibly OK", "Possibly OK", "Too High", "Too High"},
};
static String makeDecision(double pIndex, double volume) {
int row = (int) P_INDEX_TEST.stream().filter(p -> p.test(pIndex)).count();
int col = (int) VOLUME_TEST .stream().filter(p -> p.test(volume)).count();
return TABLE[row][col];
}
}
关于java - 如何在Java中实现决策矩阵？，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/58882439/