How to Retrieve a Java Enum Using Its String Value?

How can I look up a Java enum by its String value?

public enum Verbosity {
    BRIEF, NORMAL, FULL;

    private static Map<String, Verbosity> stringMap = new HashMap<>();

    static {
        for (Verbosity verbosity : Verbosity.values()) {
            stringMap.put(verbosity.name(), verbosity);
        }
    }

    public static Verbosity getVerbosity(String key) {
        return stringMap.get(key);
    }
}

Retrieving a Java enum using its String representation can be accomplished by utilizing a static map to store and quickly look up enum instances.

public enum Verbosity {
    BRIEF, NORMAL, FULL;

    private static Map<String, Verbosity> stringMap = new HashMap<>();

    static {
        for (Verbosity verbosity : Verbosity.values()) {
            stringMap.put(verbosity.name(), verbosity);
        }
    }

    public static Verbosity getVerbosity(String key) {
        return stringMap.get(key);
    }
}

Causes

• The code provided uses an instance initializer, which is not suitable because it tries to use static context within an instance method.
• Static initialization blocks must be used to initialize static members correctly.

Solutions

• Use a static initializer block to populate the map when the enum class is loaded.
• Replace `this.toString()` with `this.name()` which is more common for enum constants.

Mistake: Using `this.toString()` instead of `this.name()` in the enum context.

Solution: Use `this.name()` to get the string representation of the enum constant.

Mistake: Not initializing the static map properly in the enum.

Solution: Utilize a static block to populate the `stringMap`.