检查 Enum 是否包含列表中存在的所有值<string></string>

Question

I want to check if a list of String contains any value that is not there in the Enum.

public interface MyInterface {

public static enum MyEnum { 
    ONE,
    TWO,
    THREE,
    FOUR;
}

public otherMethodsBelow();

}

Below is my API where the user will pass the list of strings

@GET
@Path("/{path}")
public Response find(@QueryParam("list") final List<String> list) {
if(list contains the values that are present in MyEnum){ //if list is "ONE","THREE" then go inside if
    // do stuff
}else if(list contains any other value that is not present in MyEnum){ //if list is "ONE","FIVE" then go inside else if
    throw "Invalid Argument in list"
}}

My requirement is if list contain any wrong value(value which is not there in MyEnum) then it should go in the else if block and if list contains the values which are also there in the MyEnum then it should go in the if block.

Answer 1

// cache enum string values to set (constant time access time)
private static final Set<String> myEnumStringValues = Arrays.stream(MyEnum.values()).map(Enum::name).collect(Collectors.toSet());

@GET
@Path("/{path}")
public Response find(@QueryParam("list") final List<String> list) {
    // O(N), where N = at most sizeof(myEnumStringValues)
    if(myEnumStringValues.containsAll(list)){ //if list is "ONE","THREE" then go inside if
        // do stuff
    }else { //if list is "ONE","FIVE" then go inside else if
        throw "Invalid Argument in list" // you can create a copy of list and call removeAll(myEnumStringValues) -> this is not always needed, I guess usually I'll have a valid case, so it is cheaper to do that operation only if it fails
    }
}
    

Answer 2

Using streams you can map MyEnum constants to a set of String

private static final Set<String> ALL_MY_ENUMS = Arrays.stream(MyEnum.values()).map(Enum::name).collect(toSet());

@GET
@Path("/{path}")
public Response find(@QueryParam("list") final List<String> list) {
    List<String> extraValues = new ArrayList<>(list);
    extraValues.removeAll(ALL_MY_ENUMS);
    if (extraValues.isEmpty()) {
        // do stuff
    } else {
        throw "Invalid Argument in list"
    }

Answer 3

fun contains(list: List<String>): Boolean {
    for (e: MyEnum in MyEnum.values()) {
        return list.contains(e.name)
    }
    return false
}

You can use Like

if (!contains(list))

Answer 4

you may do as @Andy Turner suggested or

Set<String> set = new HashSet<>(list);
Set<String> enumSet = Arrays.stream(RequestType.values()).map(Enum::name).collect(Collectors.toSet()));
    if (set.equals(enumSet)) {

    } else {

    }