How to compare string to enum type in Java?

问题

I have an enum list of all the states in the US as following:

public enum State
{ AL, AK, AZ, AR, ..., WY }

and in my test file, I will read input from a text file that contain the state. Since they are string, how can I compare it to the value of enum list in order to assign value to the variable that I have set up as:

private State state;

I understand that I need to go through the enum list. However, since the values are not string type, how can you compare it? This is what I just type out blindly. I don't know if it's correct or not.

public void setState(String s)
{
    for (State st : State.values())
    {
        if (s == State.values().toString())
        {
           s = State.valueOf();
           break;
        }
    }
}

回答1:

try this

public void setState(String s){
 state = State.valueOf(s);
}

You might want to handle the IllegalArgumentException that may be thrown if "s" value doesn't match any "State"

回答2:

Use .name() method. Like st.name(). e.g. State.AL.name() returns string "AL".

So,

if(st.name().equalsIgnoreCase(s)) {

should work.

回答3:

to compare enum to string

for (Object s : State.values())
    {
            if (theString.equals(s.toString()))
        {
            // theString is equal State object

        }
    }

来源：https://stackoverflow.com/questions/12682553/how-to-compare-string-to-enum-type-in-java