Created map in enum using parameters

• Key: AUTQ - Value: AUTP
• Key: FAUQ - Value: FAUP

I created map but now stuck in static and non static calls within enum

AUTHOR("AUTQ","AUTP"), <--- Author is of no use but the values AUTQ is Key and AUTP is value
FINA("FAUQ","FAUP"),

private final Map<String, String> val;
MessageFunction(String key, String value){
    this.val = new HashMap<>();
    this.val.put(key.toUpperCase(), value); <--- Created a Map
}

public static String getResultValue( String fromValue) {
   
    return this.val.get(fromValue.toUpperCase()); <--- How to access it?
}

When i add static then it do not allow to call this.val (Can not be referred from static context)

When i add non static then not sure how to call it in code.

Could you please suggest how to handle this use case?

CodePudding user response：

You can create the map contents in a static block.

public enum MessageFunction {
    AUTHOR("AUTQ", "AUTP"),
    FINA("FAUQ", "FAUP");

    private static final Map<String, String> val;

    static {
        val = Arrays.stream(MessageFunction.values())
                .collect(Collectors.toMap(my -> my.key.toUpperCase(), my -> my.value));
    }

    MessageFunction(String key, String value) {
        this.key = key;
        this.value = value;
    }

    private final String key;
    private final String value;

    public static String getResultValue(String fromValue) {
        return val.get(fromValue.toUpperCase());
    }
}

Both the below calls print AUTP.

System.out.println(MessageFunction.getResultValue("AUTQ"));
System.out.println(MessageFunction.getResultValue("autq"));