Convert integer value to matching Java Enum
Solution 1:
You would need to do this manually, by adding a a static map in the class that maps Integers to enums, such as
private static final Map<Integer, PcapLinkType> intToTypeMap = new HashMap<Integer, PcapLinkType>();
static {
for (PcapLinkType type : PcapLinkType.values()) {
intToTypeMap.put(type.value, type);
}
}
public static PcapLinkType fromInt(int i) {
PcapLinkType type = intToTypeMap.get(Integer.valueOf(i));
if (type == null)
return PcapLinkType.DLT_UNKNOWN;
return type;
}
Solution 2:
There's a static method values()
which is documented, but not where you'd expect it: http://docs.oracle.com/javase/tutorial/java/javaOO/enum.html
enum MyEnum {
FIRST, SECOND, THIRD;
private static MyEnum[] allValues = values();
public static MyEnum fromOrdinal(int n) {return allValues[n];}
}
In principle, you can use just values()[i]
, but there are rumors that values()
will create a copy of the array each time it is invoked.
Solution 3:
You will have to make a new static method where you iterate PcapLinkType.values() and compare:
public static PcapLinkType forCode(int code) {
for (PcapLinkType typе : PcapLinkType.values()) {
if (type.getValue() == code) {
return type;
}
}
return null;
}
That would be fine if it is called rarely. If it is called frequently, then look at the Map
optimization suggested by others.