如何根据 Gson 中的应用程序版本使用不同的字段名称？

Question

I have a rest API running using Java and Gson and have a task to standardize the names of the fields. Unfortunately, they were created in my native language and now they need to be changed to English. I was thinking in a way where I could support old versions, passing the old field names.

Is it possible to use the @Since annotation with @SerializedName? Or any solution to change the field names dynamically based in the version?

Answer 1

As far as I know, you cannot combine @Since and @SerializedName to dynamically change field names. Another way is to use FieldNamingStrategy with a variable ver to determine which name is supposed to be used for serialization.

Following example shows if there is a field named user in your POJO, then you can change its name with different pre-defined ver (such as 0.1 or 0.2) for serialization.

Code Snippet

double ver = 0.1;
Gson gson = new GsonBuilder()
        .setFieldNamingStrategy(new FieldNamingStrategy() {
            @Override
            public String translateName(Field field) {
                if ("user".equals(field.getName())) {
                    if (ver == 0.1) {
                        return "username";
                    } else if (ver == 0.2) {
                        return "user_name";
                    } else {
                        return field.getName();
                    }
                } else {
                    return field.getName();
                }
            }
        })
        .create();