How to deserialize enum with Jackson (2.13.1)-CodePudding

I want to deserialize an enum with Jackson 2.13.1.

I found the following solution.

public enum Type {
    TYPEONE("Type1");

    private static Map<String, Type> typesMap = new HashMap<>(1);

    static {
        typesMap.put("type1", TYPEONE);
    }

    @JsonCreator
    public static Type forValue(String value) {
        return typesMap.get(value.toLowerCase());
    }

    private final String label;

    Type(String label) {
        this.label = label;
    }

    @JsonValue
    public String getLabel() {
        return label;
    }
}

Still getting the following error:

java.lang.IllegalArgumentException: No enum constant com.cas.cascrt.certificate.model.enums.Type.Type1
at java.base/java.lang.Enum.valueOf(Enum.java:266) ~[na:na]

CodePudding user response：

You don't need to maintain a map. In @JsonCreator method stream through the Type.values(), filter the incoming value and return the enum.

CodePudding user response：

Looks like your error is caused by a typo:
Instead of typesMap.put("type1", TYPEONE);
it should be typesMap.put("Type1", TYPEONE); to match the TYPEONE("Type1");.

But anyway: Using a @JsonCreator, @JsonValueand a Map for deserializing/serializing an enum from/to customized strings is kind of overkill.

You can do it much simpler just by using @JsonProperty on the enum constants.

public enum Type {
    @JsonProperty("Type1")
    TYPEONE,

    @JsonProperty("Type2")
    TYPETWO,

    @JsonProperty("Type3")
    TYPETHREE;
}