java - Gson如何排除JsonSerializer中的某些字段

Question

我只需要更改一个字段，另一个字段我想要有默认值，但使用此代码我在输出中只有一个字段 - 我在 JsonSerializer 中编写的字段，但我需要拥有所有字段并且只有一个字段为了改变。有一个属性方法可以做到这一点吗？

GsonBuilder gson = new GsonBuilder().serializeNulls();
gson.registerTypeAdapter(TripCardView.class, new JsonSerializer<TripCardView>() {
    @Override
    public JsonElement serialize(TripCardView src, Type typeOfSrc, JsonSerializationContext context) {
        JsonObject jObj = new JsonObject();
        jObj.add("numberShortYear", new JsonPrimitive(src.getNumberShortYear()));
        return jObj;
    }
});
jsonResponse.add("aaData", gson.setDateFormat("dd.MM.yyyy").create().toJsonTree(result));

Answer 1

只有一些小改动，请参阅下面代码中的注释:

gson.registerTypeAdapter(TripCardView.class, new JsonSerializer<TripCardView>() {
    // You need to create a new Gson in your serializer because calling original contex
    // would call this serializer again and cause stack overflow because of recursion
    private Gson gson = new GsonBuilder().setDateFormat("dd.MM.yyyy").create();
    @Override
    public JsonElement serialize(TripCardView src, Type typeOfSrc, 
                JsonSerializationContext context) {
        // You need to serialize the original object to have its fields populated 'default'
        JsonElement result = gson.toJsonTree(src);
        // After that it is just to add the extra field with value from method call
        result.getAsJsonObject().add("numberShortYear",
                new JsonPrimitive(src.getNumberShortYear()));
        return result;
    }
});