java循环遍历枚举值的子集

Question

我有一个带有4个值的枚举，还有一个接受枚举值的方法签名。我希望能够处理所有未作为doSomething（）参数传递的枚举值

public void doSomething(EnumThing thing){
   EnumThing[] thingValues = EnumThing.values();
   List<EnumThing> valuesNotPassedAsArg = new ArrayList<EnumThing>();
   for(EnumThing th : thingValues){
       valuesNotPassedAsArg.add(th);
   }
   valuesNotPassAsArg.remove(thing);
  //here I would loop through all valuesNotPassAsArg and do something with them
}

public enum EnumThing{
 SOMETHING, SOMETHINGELSE, ANOTHERTHING;
}

有没有更干净的方法？我觉得从thingValues数组获取项目的循环是多余的

Answer 1

我想说，这样会好一点

public void doSomething(EnumThing thing){
   EnumThing[] thingValues = EnumThing.values();
   List<EnumThing> valuesNotPassedAsArg = Arrays.asList(thingValues);
   valuesNotPassAsArg.remove(thing);
   //here I would loop through all valuesNotPassAsArg and do something with them
}
public enum EnumThing{
   SOMETHING, SOMETHINGELSE, ANOTHERTHING;
}

Answer 2

另一种方法是使用Stream.of方法。例如：

public class EnumTest {

    public static enum MyEnum {
        VALUE1, VALUE2, VALUE3
    }

    public static void main(String[] args) {
        Stream.of(MyEnum.values()).filter(v -> v != MyEnum.VALUE2).forEach(System.out::println);
    }
}

其中打印：

VALUE1
VALUE3

Answer 3

public void doSomething(EnumThing thing){
   EnumThing[] thingValues = EnumThing.values();
   for(EnumThing th : thingValues){
       if (th != thing) {
          doSomethingElse(th);
       }
   }
}

Answer 4

查看EnumSet。具体来说,

import java.util.EnumSet;
import static java.util.EnumSet.complementOf;

for (EnumThing t : complementOf(EnumSet.of(thing))) {
  ... do the work ...
}

Answer 5

@Marko的答案比这更好，但了解这种替代方法可能会有所帮助

public static void main(String[] args) {
    EnumThing thing = EnumThing.ANOTHERTHING;

    List<EnumThing> list = new ArrayList<EnumThing>(Arrays.asList(EnumThing.values()));
    list.remove(thing);
    System.out.println(list);
}



public enum EnumThing{
    SOMETHING, SOMETHINGELSE, ANOTHERTHING;
}

这是打印出来的

[SOMETHING, SOMETHINGELSE]

Answer 6

查看标题，迭代一个范围

for (int i = YourEnum.___RANGE___START___.ordinal() +1; i != YourEnum.__RANGE___END___.ordinal() ; i++) {
    YourEnumvalue = YourEnum.values()[i];
    //use value
}

还是这个

for (YourEnum value: EnumSet.range(YourEnum.___RANGE___START___, YourEnum.__RANGE___END___)) {
    // use value
}

如果您只想跳过一个元素，那么Skip Head's solution可能会优于complementOf，这在单次迭代的情况下似乎是过分了