Get Enum instance

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Lookup Java enum by string value 23 answers

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Try this out. I have created a method which searches type using id:

public static Type getType(int id) {

    for (Type type : Type.values()) {
        if (id == type.getId()) {
            return type;
        }
    }
    return null;
}

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您可以构建一个映射来执行此查找。

static final Map<Integer, Type> id2type = new HashMap<>();
static {
    for (Type t : values())
        id2type.put(t.id, t);
}
public static Type forId(int id) {
    return id2type.get(id);
}

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Create a method inside the Type class returning the Enum instances:

Type get(int n) {
    switch (n) {
    case 1:
        return Type.ADMIN;
    case 2:
        return Type.EMPLOYEE;
    case 3:
        return Type.HIRER;
    default:
        return null;
    }

}

TIP: you need to add default in switch-case or add a return null at the end of the method to avoid compiler errors.

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UPDATE (thanks to @AndyTurner):

It would be better to loop and refer to the id field, so you're not duplicating the IDs.

Type fromId(int id) {
    for (Type t : values()) {
        if (id == t.id) {
            return t;
        }
    }
    return null;
}

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