Add enum alias name or change name

Question

Java enum’s name declare in source code, as some reason, we want to change its name to another one.

For Example

Have a enum:

enum modifier {
    _public, _private, _protected;
}   

As we know “public”, “private”,”protected” are java reserved keywords, add ‘_’ to head of them for enum names. But you want name(), toString() method return “public” and etc.

Resolution

We can change name, supporting Enum.valueOf(), by reflection.

enum modifier {
    _public, _private, _protected;

    static {
        try {
            Field efield = Enum.class.getDeclaredField("name");
            efield.setAccessible(true);
            efield.set(modifier._public, "public");
            efield.set(modifier._private, "private");
            efield.set(modifier._protected, "protected");
            Method dirMethod = Class.class.getDeclaredMethod("enumConstantDirectory");
            dirMethod.setAccessible(true);
            Map<String, modifier> cTypeMap = (Map<String, modifier>) dirMethod.invoke(modifier.class);
            cTypeMap.put("_public", modifier._public);
            cTypeMap.put("_private", modifier._private);
            cTypeMap.put("_protected", modifier._protected);
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }
}

    public static void main(String[] args) {
        System.out.println(Arrays.deepToString(modifier.values()));
        System.out.println(Enum.valueOf(modifier.class, "_public"));
        System.out.println(Enum.valueOf(modifier.class, "public"));
    }

We can see the following output:

[public, private, protected]
public
public

Enjoy it